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Utilization of preoperative imaging in uterine cancer patients
Gynecologic Oncology 115 (2009) 226–230
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Gynecologic Oncology j o u r n a l h o m e p a g e : w w w. e l s e v i e r. c o m / l o c a t e / y g y n o
Utilization of preoperative imaging in uterine cancer patients Lilian T. Gien a,⁎, Lisa Barbera b,c,d, Rachel Kupets a, Refik Saskin c, Lawrence Paszat c,d a
Division of Gynecologic Oncology, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada c Institute of Clinical Evaluative Sciences, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada d Department of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada b
a r t i c l e
i n f o
Article history: Received 30 April 2009 Available online 15 August 2009 Keywords: Computed tomography Magnetic resonance imaging Uterine cancer Endometrial cancer Preoperative
a b s t r a c t Objective. Improvements in imaging technology over time have led to its increasingly widespread use in health care, even when the imaging may not be indicated. This study evaluates patterns of preoperative ultrasound, CT and MRI use among uterine cancer patients in Ontario. Methods. This population-based study identified women diagnosed with uterine malignancy from 1995– 2005 in the Ontario Cancer Registry. Record linkages were made to other healthcare databases to characterize residence, socioeconomic status, comorbidities, and timing of investigations surrounding diagnosis. Results. We identified 12,522 women who received surgery for uterine adenocarcinoma or sarcoma, of which 9145 (73%) had a preoperative ultrasound, and 1148 (9.2%) had a preoperative CT and/or MRI. Over 10 years, the rate of CT use increased 4.5-fold while MRI use increased 10.6-fold. There were no significant differences in CT/MRI use among patients with increased comorbidities, urban residence or socioeconomic status. Higher rates of CT/MRI use were associated with non-endometrioid high-risk histology (33.5% vs 14.6%, p b 0.0001). Median time from ultrasound to surgery was 11.6 weeks. Time from diagnosis to surgery was 2 weeks longer if a preoperative CT/MRI was done. Half of these tests were ordered by non-gynecologists. Conclusions. The rate of preoperative CT and MRI use in patients with uterine cancer has increased twice as much as the reported rate in cancer patients overall. Given the questionable utility of preoperative CT/MRI in this disease, guidelines should be developed for use of these imaging tests in uterine cancer, especially when use is associated with a delay in surgery. © 2009 Elsevier Inc. All rights reserved.
Introduction Endometrial cancer is the most common gynecologic malignancy in North America. In 2008, approximately 4200 new cases were diagnosed in Canada, with an estimated 790 deaths from this disease [1]. Once a diagnosis is established from an endometrial biopsy, the primary treatment of endometrial cancer is surgical, consisting of at least a total hysterectomy and bilateral salpingo-oophorectomy, and can include a surgical staging procedure with pelvic and para-aortic node dissection and peritoneal cytology. Although the majority of patients with endometrial cancer present with early stage disease, approximately 12% of patients will have evidence of lymph node metastasis at the time of surgery [2]. Most gynecologic oncologists will complete a surgical staging procedure for patients at intermediate or high risk of lymph node metastasis to help guide decisions regarding adjuvant treatment such as radiation or chemotherapy.
⁎ Corresponding author. Dr. Lilian Gien, Odette Cancer Centre, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, Ontario, Canada M4N 3M5. Fax: +1 416 480 6002. E-mail address: [email protected] (L.T. Gien). 0090-8258/$ – see front matter © 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.ygyno.2009.07.025
Interest has developed in using non-invasive imaging techniques such as preoperative computed tomography (CT) and magnetic resonance imaging (MRI) to help predict depth of myometrial invasion, cervical involvement, and enlarged lymph nodes. Numerous studies have quoted variable sensitivity and specificity rates for these imaging tests. For detection of myometrial invasion, CT scan has a sensitivity of 57–83% and specificity of 42–92%, while MRI has a sensitivity of 56–92% and specificity of 82–90% [3–6]. The American College of Obstetrics and Gynecology (ACOG) Guidelines for the management of endometrial cancer has stated there is no role for preoperative CT or MRI in this disease [7]. Studies demonstrate these tests alter management in only 4–8% [4,8], and the majority of errors in interpretation occur in early stage endometrial cancer where CT or MRI overestimate the extent of disease [9]. Studies have shown an increase in CT and MRI use over the past two decades. Specifically, in Ontario between 1993 and 2002, the use of these tests for cancer-specific indications increased 2.3-fold for CT scans and 4.6-fold for MRI [10,11]. This is significant given the potential costs and waiting times, not only for the tests themselves, but also for subsequent treatment pending the completion of imaging. The primary objective of this study was to evaluate patterns of preoperative ultrasound, CT and MRI use among uterine cancer
L.T. Gien et al. / Gynecologic Oncology 115 (2009) 226–230
patients in Ontario. Secondary objectives included determining an association between CT/MRI imaging and gynecologic oncology consults or surgical staging, and the impact of waiting times for surgery in women with this disease. Methods This is a population-based study using data at the Institute of Clinical Evaluative Sciences (ICES), which houses the health records for 12.5 million residents of the province of Ontario, Canada. Ethics approval for this study was obtained through the Research Ethics Board at Sunnybrook Health Sciences Centre. Data sources Data were obtained from the Ontario Cancer Registry (OCR), the Ontario Health Insurance Plan (OHIP), the Registered Persons Database (RPDB), the Canadian Institute for Health Information (CIHI) Discharge Abstract Database (DAD), and the Corporate Physicians' Database (CPD). The OCR has registered all cases of invasive cancer diagnosed in Ontario since 1964 and captures 95% of cancer cases [12]. The OHIP database contains all physician billing records for services provided to Ontario residents since July 1, 1991. Information on radiology imaging and procedures billed for each patient are recorded, along with a service date, provider and institutional identification. The RPDB contains information for all beneficiaries of OHIP since 1991 and includes data such as age, gender, postal code of residence, and vital status. The CIHI-DAD records procedure codes from all inpatient and outpatient hospital admissions, and patient comorbidities at the time of admission to hospital with maximum discrepancy rates of 10% and 11%, respectively, in reported studies on re-abstraction [13]. Comorbidities were classified using Deyo's clinical comorbidity index for administrative databases [14]. The CPD lists all physicians practicing medicine and their specialties in the province of Ontario. Canada's 2001 Census provided data on neighbourhood income quintiles that were linked to individuals using a postal code conversion file to impute socioeconomic status [15]. All databases housed at ICES can be linked by a common unique numeric identifier. Cohort Incident cases of uterine cancer (ICD-9 codes 179 or 182; ICD-10 codes C54 or C55) were identified in the OCR from 1995 to 2005. Exclusion criteria were applied: male gender, age under 18, previous malignancy 3 years prior to diagnosis of endometrial cancer, those with an invalid OHIP number or no recent postal code, any histology other than adenocarcinoma or sarcoma of the uterus, and those who did not have surgery as part of their treatment. Variables Patient variables Variables obtained from OCR included diagnosis date, age at diagnosis, and histology of disease. No staging information is available from this database. Linkage to RPDB and Canadian census data were used for demographics and socioeconomic status, while linkage to CIHI-DAD determined patient comorbidities. Treatment variables This cohort was then linked to the OHIP and CIHI-DAD databases to obtain data regarding investigations and procedures completed 6 months prior to and 6 months after diagnosis of uterine cancer, such as preoperative pelvic or transvaginal ultrasound, preoperative endometrial biopsy (office biopsy and dilatation and curettage), preoperative pelvic/abdominal CT and/or MRI, and the date and type
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of surgical procedure. Surgical procedures were classified as “staging” if the procedure included either a pelvic and/or para-aortic node dissection. Linkage to the OHIP and CPD obtained data on consults to gynecologic oncologists, and the specialty of the physician ordering preoperative investigations and performing patient surgeries, respectively. Analysis The group with preoperative CT and/or MRI was compared to those without preoperative CT and/or MRI to see if use varied according to age, comorbidities, socioeconomic status, location of dwelling (rural or urban), or tumor histology. The rates of CT and MRI use were calculated over time. The time from investigation to final surgery was calculated for those with ultrasound, CT or MRI; time to surgery for those with preoperative imaging were compared to those without. Finally, the two groups were compared to see if there was an association with preoperative imaging and consults to gynecologic oncology, or to surgical staging. Statistical analysis was performed using SAS 9.1. The Student t-test was used for comparison of continuous data, and the Chi-Squared test for categorical data, with 95% confidence intervals. Multivariate logistic regression analysis was performed to determine independent factors associated with performance of imaging. Clinically important variables that were thought to potentially influence preoperative imaging were chosen a priori and entered into the model. A two-tailed p b 0.05 was considered statistically significant. Results 14,665 women were diagnosed with uterine cancer in Ontario between 1995 and 2005. After excluding patients with histology other than adenocarcinoma or sarcoma (n = 981) and patients who did not have surgery as part of their management (n = 1162), 12,522 women were eligible for analysis. The mean age was 63.4 years, with the majority (87.5%) over the age of 50, and presumably postmenopausal. 83.7% of patients had endometrioid type histology. The OCR did not include details regarding grade. 16.3% were classified as having high risk histology, such as serous, clear cell, undifferentiated, or sarcoma. The majority of patients (81.8%) had at least a total abdominal hysterectomy and bilateral salpingo-oophorectomy as part of their treatment. 16.2% of patients underwent a staging procedure which included pelvic and/or para-aortic lymphadenectomy. The baseline characteristics of this cohort are presented in Table 1. Preoperative investigations 73% of the cohort (n = 9145) had a preoperative ultrasound, with the majority done prior to obtaining a histologic diagnosis of cancer (n = 8458, 92.5%). The median time between ultrasound and a biopsyproven diagnosis was 47 days. Most of these ultrasounds were ordered by non-gynecologists (73.3%); 67.4% (n = 5540) were family physicians and 26.7% (n = 2197) were gynecologists. 73.5% (n = 9198) had an endometrial biopsy or dilatation and curettage done prior to surgery resulting in a diagnosis of uterine cancer, while 23.2% (n = 2906) were diagnosed with a malignancy from the pathologic specimen obtained from definitive surgery. 1148 patients (9.2%) had a preoperative CT or MRI as part of their preoperative investigations. Preoperative CT and/or MRI use The characteristics of the group with preoperative CT and/or MRI were compared to those without preoperative CT and/or MRI to determine if any variables were associated with obtaining these
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Table 1 Baseline characteristics.
Table 3 Predictors of preoperative imaging by multivariate regression analysis.
Variable
N (total = 12,522)
Age N 50 years ≤ 50 years Comorbidity (Charlson score) 0 ≥1 Residencea Urban Rural Income quintileb 1 (lowest) 2 3 4 5 Unknown Histology Endometrioid Serous/clear cell/sarcoma Surgery Hysterectomy (Hyst)/BSO Hyst/BSO + nodesc Laparotomy (“open/close”)
%
10,956 1566
87.5 12.5
11,100 1422
88.6 11.4
10,564 1945
84.5 15.6
2186 2469 2461 2550 2629 227
17.5 19.7 19.7 20.4 21.0 1.8
10,480 2042
83.7 16.3
10,239 2027 256
81.8 16.2 2.0
Variable
Hazard ratio
95% Confidence intervals
Age Comorbidity (Charlson score ≥1) Urban residence Income quintilea 1 (lowest) 2 3 4 5 Histology (high riskb)
1.01 1.23 1.31
1.00–1.01 1.03–1.48 1.09–1.57
1.23 1.03 0.98 0.92 1.0 2.91
1.02–1.50 0.85–1.25 0.81–1.20 0.76–1.13 – 2.54–3.32 (p b 0.0001)
a b
Reference category is income quintile 5, represented by HR 1.0. Papillary serous, clear cell, undifferentiated, or sarcoma.
ordered by gynecologic oncologists. The majority of CT scans (50%) were ordered by non-gynecologists, 42% of whom were family physicians. Among MRI scans ordered, 54% were ordered by gynecologic oncologists, while 22% were general gynecologists and 24% were non-gynecologists (Fig. 2). Association with consults to gynecologic oncology and staging
BSO = bilateral salpingo-oophorectomy. a Missing variable in 13. b Missing variable in 203. c Pelvic +/− para-aortic lymphadenectomy.
images. There were no clinically significant differences in the two groups with regard to age, comorbidities, region of dwelling or socioeconomic status (Table 2). However, there was a higher proportion of patients in the preoperative imaging group who had high risk tumor histology, namely serous, clear cell, undifferentiated type, and sarcomas (33.5% vs 14.6%, p b 0.0001). When these same factors were analyzed by multivariate regression analysis, high risk tumor histology was the only independent prognostic factor associated with preoperative imaging that was both statistically and clinically significant (odds ratio [OR] 2.91, 95% confidence intervals [CI] 2.54–3.32, p b 0.0001). Although other factors were statistically significant in this analysis, the odds ratios of these variables were close to 1.0, and therefore these results likely reflect the large sample size of this cohort (Table 3). The rate of CT and MRI use was calculated between 1995 and 2005. There was a 4.5-fold increase in CT use over 10 years. Meanwhile, there was a 10.6-fold increase in MRI use over the same time period (Fig. 1). Of all the patients receiving CT or MRI, 10% of patients received both CT and MRI preoperatively. The physician ordering the imaging test was identified for 80% of CT scans (n = 846) and 71% of MRIs (n = 145). Among the CT scans ordered, 35% were ordered by general gynecologists, while 15% were
Overall, 31.4% had a consultation with a gynecologic oncologist, and 19% had their surgical procedure done by a gynecologic oncologist. Staging, which was defined as having a pelvic and/or para-aortic node dissection, was completed in 16.2% of patients. There was a significant difference in the number of consultations with a gynecologic oncologist, with 52.7% in the preoperative imaging group compared to 29.2% in the non-preoperative imaging group (p b 0.0001). Additionally, there was a significant difference in the proportion of those who had a staging procedure; 37.2% in the preoperative imaging group had a pelvic and/or para-aortic node dissection, compared to 14.1% in the non-preoperative imaging group (p b 0.0001). However, from this data we are unable to determine the timing of the imaging test in relation to the consultation, and whether the imaging influenced the decision to surgically stage. Time from diagnosis to surgery The median time from having an ultrasound to having a biopsyproven histologic diagnosis of cancer was 47 days. The median time from histologic diagnosis to definitive surgery was 34 days. Using ultrasound as a surrogate for seeking medical attention because of concern of vaginal bleeding, the median time from ultrasound to surgery was 81 days, or 11.6 weeks. When comparing the groups with and without preoperative CT/ MRI, the median time from biopsy-proven histologic diagnosis of
Table 2 Comparison of characteristics of those with and without preoperative CT +/− MRI. Variable
Preop CT +/− MRI (n = 1148)
No preop CT +/− MRI (n = 11,374)
Age (years) Comorbidity ≥1 (Charlson score) Urban residence Income quintile 1 (lowest) 2 3 4 5 Histology (high riska)
64.6 13.8% 87.4%
63.3 11.1% 84.2%
21.0% 19.8% 18.9% 18.3% 20.4% 33.5%
17.1% 19.8% 19.8% 20.6% 21.1% 14.6%b
a b
Papillary serous, clear cell, undifferentiated, or sarcoma. p b 0.0001.
Fig. 1. Rate of CT and MRI use in uterine cancer patients over time.
L.T. Gien et al. / Gynecologic Oncology 115 (2009) 226–230
Fig. 2. Physicians ordering preoperative CT and MRI scans.
cancer to surgery was 35 days in the group without preoperative imaging, and 49 days in the group with preoperative imaging. In other words, the time from histologic diagnosis to definitive surgery was 2 weeks longer if a CT or MRI was obtained preoperatively. This was a statistically significant difference (p b 0.0001). Discussion This study demonstrates that pre-diagnosis ultrasound is commonplace and the rate of preoperative CT and MRI use for uterine cancer has increased significantly over the past 10 years. Compared to all cancer patients with a previously reported 2.3-fold increase in CT use and 4.6-fold increase in MRI use [11], in uterine malignancies the rates were twice as high with a 4.6-fold increase in CT and 10.6-fold increase in MRI. These increases are difficult to justify given the questionable utility of these preoperative tests. Depth of myometrial invasion is a known risk factor for lymph node metastasis, where tumor invasion into the outer half of the myometrium can result in positive nodes in 25%, compared to 1% for tumors isolated to the endometrium [2]. Some practitioners believe preoperative CT/MRI may be warranted to predict for myometrial invasion and triage those who require surgical staging. However, intraoperative gross visual inspection of the bivalved uterus has a sensitivity of 84%, specificity of 91% [16], and an overall accuracy rate of 85% [17,18], similar to the accuracy rate for predicting myometrial invasion by MRI [17]. Likewise, MRI provides a minimal additional benefit when compared to intraoperative frozen section [19]. Furthermore, Zerbe et al. [20] reported the sensitivity of CT scans in predicting any degree of myometrial invasion, lymph node or cervical involvement to be only 50–60%. Therefore, it is difficult to justify preoperative imaging to predict myometrial invasion when the intraoperative assessment has at least a similar accuracy to MRI and improved sensitivity compared to CT. Some physicians may order CT/MRI in case imaging alters management. In a study by Connor et al. [4], preoperative CT scans were done in 15% of patients with uterine malignancies. Of the 75 patients, only six (8%) had treatments modified based on CT scans, of which two (3%) had advanced disease prohibiting primary surgery [4]. More recently, Bansal et al. [8] reported on 250 patients who underwent preoperative CT scans for uterine cancer. In those with endometrioid histology, 7–9% had findings on imaging suggesting metastases, but only 4% had management altered. In our study, the cohort only consisted of uterine cancer patients who had surgery as part of their treatment. On exploratory analysis, the 1162 patients who did not have surgery and were excluded from the cohort were compared to the surgery group. Median age was 69 years compared to 63 years (p b 0.0001), and the comorbidity index
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was higher in 25%, versus 11% in the surgery group (p b 0.0001). Furthermore, of the 1162 patients who did not have surgery, 48% had a CT/MRI as part of their investigations, but it could not be determined when the imaging was done in relation to the decision to have surgery, or whether the imaging was done for monitoring during subsequent treatment. The study design prohibited knowing the results from the imaging tests. Therefore, we cannot predict how many patients had treatment altered by these tests. Based on previously reported studies [4,8], this number is likely small. Additionally, it has been reported that an expenditure of $17,622 (US) for CT imaging is required to alter the management of one patient [8]. In a publicly funded health care system, the routine use of these tests with their associated costs cannot be supported. Our study demonstrated that the presence of serous, clear cell, undifferentiated carcinoma or sarcoma was associated with increased CT and MRI use. Since these histologies have a greater risk of peritoneal and lymphatic dissemination, it is not surprising that the imaging rate is higher in this group. Bansal et al. [8] also reported that CT scans altered management in 11% of serous or clear cell carcinomas and 13% of sarcomas, which suggests the use of CT/MRI for high risk histology may be more useful compared to those with endometrioid histology. However, it is also arguable that if staging will be completed in this high risk group regardless of its findings, the goal of imaging is questionable. There are several limitations to this study. The indication for the CT/MRI is not available from the databases. Therefore, CT/MRIs done in the preceding 6 months for reasons other than their uterine cancer work-up could result in an overestimation of imaging tests. Alternatively, MRI scans performed for inpatient scans have no OHIP billing and therefore the rate of MRI use could be underestimated. Additionally, we cannot determine whether the association of preoperative CT/MRI with a higher rate of gynecologic oncology consults and lymphadenectomies is a result of causation. It is not possible from our methods to determine if the results from the imaging led to a referral to gynecologic oncology and the decision to stage, or whether the consult or the decision to stage led to ordering the preoperative imaging. It is likely that these variables are confounded by histology. Those with high risk histologic subtypes received more preoperative imaging, and these same patients were more likely to be referred to a gynecologic oncologist for consultation and subsequent surgical staging. The results of the CT and MRI scans would have to be known to determine whether the imaging had an effect on management. Further work with the individual chart review of all cases across the province would be required to describe the true relationship among preoperative imaging, consults to gynecologic oncology, and surgical staging. The absence of stage of disease from the databases is also a limitation. We cannot determine whether there were a higher proportion of patients with Stage III or IV disease in the non-operative group or whether imaging had any influence in this decision. However, the number of patients who present with peritoneal carcinomatosis from uterine cancer who cannot be managed with surgery is likely to be small. We also cannot determine whether imaging was done for Stage II disease if there was suspicion of cervical involvement on clinical exam, and whether imaging influenced management. Ideally, it would be useful to correlate stage data with what was found on imaging results, but that is not possible with this population study based on the absence of such information from the databases. Furthermore, the reason for ordering the tests is unknown. The majority of physicians ordering CT scans were non-gynecologists, 42% of which were family physicians. In an era where CT scans are increasingly prevalent, perhaps non-gynecologists presume that ordering a CT is helpful for the subspecialist managing the disease. Alternatively, it is unknown whether gynecologic oncologists are requesting a CT scan to be ordered prior to consultation, although, arguably, the imaging rate for gynecologic oncologists should be
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lower since they are trained to perform lymphadenectomies. Given the limited utility of preoperative CT scans in this disease, development of guidelines for tests in uterine cancer patients would be helpful for all physicians involved in the care of these women. Finally, this study demonstrated significant delays during the preoperative work-up for patients with uterine cancer. The majority of women with postmenopausal bleeding had an ultrasound by their family physician prior to having an endometrial biopsy by a gynecologist. The cumulative wait times for the ultrasound and consult to a gynecologist, and the additional wait time for surgery resulted in a median of 11.6 weeks between symptoms and definitive surgery. This time is an underestimate because it does not account for the time the patient waited for the ultrasound. An ultrasound in a woman with postmenopausal bleeding should not be the first step in management, given that an endometrial biopsy is needed regardless of the thickness of the endometrial lining [21]. In order to improve delays in diagnosis and treatment, further dissemination of information is needed for both patients and physicians that the first test for postmenopausal bleeding is an endometrial biopsy. The median time from histologic diagnosis to surgery for those with preoperative CT/MRI scans was 2 weeks longer than those without these preoperative tests. For the subset which had both CT and MRI preoperatively, this could potentially be a longer delay. Although we cannot confirm whether the longer waiting time is caused by the imaging studies, or whether the imaging is done while awaiting surgery delayed for other reasons, the delay is another reason to deter from a preoperative CT/MRI, especially when management is rarely altered by these tests. The routine use of CT/MRI scans preoperatively in uterine cancer is of limited value and should not be universally used for all patients diagnosed with this disease. The rate of CT and MRI use in uterine cancer patients has increased twice that of cancer patients in general. This is the first study to evaluate the pattern of CT and MRI use in uterine cancer using administrative databases, and represents what is occurring in our health care system. This study generates questions regarding the indications for CT or MRI use in this disease. Further guidelines should be developed for imaging tests in uterine cancer, especially since its use is associated with a delay in surgery. Conflict of interest statement There are no conflicts of interest declared.
Acknowledgments This was presented at the International Gynecologic Cancer Society 12th Biennial Meeting, October 2008, Bangkok, Thailand. Lisa Barbera, MD, is an Ontario Ministry of Health and Long Term Care Career Scientist.
References [1] Canadian Cancer Society, National Cancer Institute of Canada: Canadian cancer statistics. Toronto, ON, 2008, [2] Creasman WT, Morrow CP, Bundy BN, Homesley HD, Graham JE, Heller PB. Surgical pathologic spread patterns of endometrial cancer: a gynecologic oncology group study. Cancer 1987;60:2035–41. [3] Barwick TD, Rockall AG, Barton DP, Sohaib SA. Imaging of endometrial adenocarcinoma. Clin Radiol 2006;61:545–55. [4] Connor JP, Andrews JI, Anderson B, Buller RE. Computed tomography in endometrial cancer. Obstet Gynecol 2000;95:692–6. [5] Hardesty LA, Sumkin JH, Hakim C, Johns C, Nath M. The ability of helical CT to preoperatively stage endometrial carcinoma. Am J Roentgenol 2001;176:603–6. [6] Ortashi O, Jain S, Emannuel O, Henry R, Wood A, Evans J. Evaluation of the sensitivity, specificity, positive and negative predictive values of preoperative magnetic resonance imaging for staging endometrial cancer. A prospective study of 100 cases at the Dorset Cancer Centre. Eur J Obstet, Gynecol Reprod Biol 2008;137:232–5. [7] ACOG Practice Bulletin Number 65: Management of endometrial cancer., 2005, [8] Bansal N, Herzog TJ, Brunner-Brown A, Wethington SL, Cohen CJ, Burke WM, Wright JD. The utility and cost-effectiveness of preoperative computed tomography for patients with uterine malignancies. Gynecol Oncol 2008;111:208–12. [9] Chung HH, Kang SB, Cho JY, Kim JW, Park NH, Song YS, Kim SH, Lee HP. Accuracy of MR imaging for the prediction of myometrial invasion of endometrial carcinoma. Gynecol Oncol 2007;104:654–9. [10] Coburn N, Przybysz R, Barbera L, Hodgson D, Sharir S, Laupacis A, Law C. CT, MRI and ultrasound scanning rates: evaluation of cancer diagnosis, staging and surveillance in Ontario. J Surg Oncol 2008;98:490–9. [11] Coburn N, Przybysz R, Law C, Barbera L, Hodgson D, Sharir S, Laupacis A. Utilization of CT and MRI Scanning among Cancer Patients in Ontario, 1993–2002.; in Report II. Toronto: Institute for Clinical Evaluative Sciences; 2005. [12] Robles SC, Marrett LD, Clarke EA, Risch HA. An application of capture–recapture methods to the estimation of completeness of cancer registration. J Clin Epidemiol 1988;41:495–501. [13] Richards J, Brown A, Homan C: The data quality study of the Canadian discharge abstract database: Proceedings of Statistics Canada Symposium, 2001, [14] Deyo RA, Cherkin DC, Ciol MA. Adapting a clinical comorbidity index for use with ICD-9-CM administrative databases. J Clin Epidemiol 1992;45:613–9. [15] Wilkins R. PCCF+ Version 3G Users Guide: Automated Geographic Coding Based on the Statistics Canada Postal Code Conversion Files. Ottawa: Statistics Canada; 2001. [16] Vorgias G, Hintipas E, Katsoulis M, Kalinoglou N, Dertimas B, Akrivos T. Intraoperative gross examination of myometrial invasion and cervical infiltration in patients with endometrial cancer: decision-making accuracy. Gynecol Oncol 2002;85:483–6. [17] Cunha TM, Felix A, Cabral I. Preoperative assessment of deep myometrial and cervical invasion in endometrial carcinoma: comparison of magnetic resonance imaging and gross visual inspection. Int J Gynecol Cancer 2001;11:130–6. [18] Franchi M, Ghezzi F, Melpignano M, Cherchi PL, Scarabelli C, Apolloni C, Zanaboni F. Clinical value of intraoperative gross examination in endometrial cancer. Gynecol Oncol 2000;76:357–61. [19] Sanjuan A, Cobo T, Pahisa J, Escaramis G, Ordi J, Ayuso JR, Garcia S, Hernandez S, Torne A, Martinez Roman S, Lejarcegui JA, Vanrell JA. Preoperative and intraoperative assessment of myometrial invasion and histologic grade in endometrial cancer: role of magnetic resonance imaging and frozen section. Int J Gynecol Cancer 2006;16:385–90. [20] Zerbe MJ, Bristow R, Grumbine FC, Montz FJ. Inability of preoperative computed tomography scans to accurately predict the extent of myometrial invasion and extracorporal spread in endometrial cancer. Gynecol Oncol 2000;78:67–70. [21] Brand A, Dubuc-Lissoir J, Ehlen TG, Plante M. Diagnosis of endometrial cancer in women with abnormal uterine bleeding: SOGC clinical practice guidelines. J SOGC 2000;22:102–4.
Contents lists available at ScienceDirect
Gynecologic Oncology j o u r n a l h o m e p a g e : w w w. e l s e v i e r. c o m / l o c a t e / y g y n o
Utilization of preoperative imaging in uterine cancer patients Lilian T. Gien a,⁎, Lisa Barbera b,c,d, Rachel Kupets a, Refik Saskin c, Lawrence Paszat c,d a
Division of Gynecologic Oncology, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada c Institute of Clinical Evaluative Sciences, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada d Department of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada b
a r t i c l e
i n f o
Article history: Received 30 April 2009 Available online 15 August 2009 Keywords: Computed tomography Magnetic resonance imaging Uterine cancer Endometrial cancer Preoperative
a b s t r a c t Objective. Improvements in imaging technology over time have led to its increasingly widespread use in health care, even when the imaging may not be indicated. This study evaluates patterns of preoperative ultrasound, CT and MRI use among uterine cancer patients in Ontario. Methods. This population-based study identified women diagnosed with uterine malignancy from 1995– 2005 in the Ontario Cancer Registry. Record linkages were made to other healthcare databases to characterize residence, socioeconomic status, comorbidities, and timing of investigations surrounding diagnosis. Results. We identified 12,522 women who received surgery for uterine adenocarcinoma or sarcoma, of which 9145 (73%) had a preoperative ultrasound, and 1148 (9.2%) had a preoperative CT and/or MRI. Over 10 years, the rate of CT use increased 4.5-fold while MRI use increased 10.6-fold. There were no significant differences in CT/MRI use among patients with increased comorbidities, urban residence or socioeconomic status. Higher rates of CT/MRI use were associated with non-endometrioid high-risk histology (33.5% vs 14.6%, p b 0.0001). Median time from ultrasound to surgery was 11.6 weeks. Time from diagnosis to surgery was 2 weeks longer if a preoperative CT/MRI was done. Half of these tests were ordered by non-gynecologists. Conclusions. The rate of preoperative CT and MRI use in patients with uterine cancer has increased twice as much as the reported rate in cancer patients overall. Given the questionable utility of preoperative CT/MRI in this disease, guidelines should be developed for use of these imaging tests in uterine cancer, especially when use is associated with a delay in surgery. © 2009 Elsevier Inc. All rights reserved.
Introduction Endometrial cancer is the most common gynecologic malignancy in North America. In 2008, approximately 4200 new cases were diagnosed in Canada, with an estimated 790 deaths from this disease [1]. Once a diagnosis is established from an endometrial biopsy, the primary treatment of endometrial cancer is surgical, consisting of at least a total hysterectomy and bilateral salpingo-oophorectomy, and can include a surgical staging procedure with pelvic and para-aortic node dissection and peritoneal cytology. Although the majority of patients with endometrial cancer present with early stage disease, approximately 12% of patients will have evidence of lymph node metastasis at the time of surgery [2]. Most gynecologic oncologists will complete a surgical staging procedure for patients at intermediate or high risk of lymph node metastasis to help guide decisions regarding adjuvant treatment such as radiation or chemotherapy.
⁎ Corresponding author. Dr. Lilian Gien, Odette Cancer Centre, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, Ontario, Canada M4N 3M5. Fax: +1 416 480 6002. E-mail address: [email protected] (L.T. Gien). 0090-8258/$ – see front matter © 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.ygyno.2009.07.025
Interest has developed in using non-invasive imaging techniques such as preoperative computed tomography (CT) and magnetic resonance imaging (MRI) to help predict depth of myometrial invasion, cervical involvement, and enlarged lymph nodes. Numerous studies have quoted variable sensitivity and specificity rates for these imaging tests. For detection of myometrial invasion, CT scan has a sensitivity of 57–83% and specificity of 42–92%, while MRI has a sensitivity of 56–92% and specificity of 82–90% [3–6]. The American College of Obstetrics and Gynecology (ACOG) Guidelines for the management of endometrial cancer has stated there is no role for preoperative CT or MRI in this disease [7]. Studies demonstrate these tests alter management in only 4–8% [4,8], and the majority of errors in interpretation occur in early stage endometrial cancer where CT or MRI overestimate the extent of disease [9]. Studies have shown an increase in CT and MRI use over the past two decades. Specifically, in Ontario between 1993 and 2002, the use of these tests for cancer-specific indications increased 2.3-fold for CT scans and 4.6-fold for MRI [10,11]. This is significant given the potential costs and waiting times, not only for the tests themselves, but also for subsequent treatment pending the completion of imaging. The primary objective of this study was to evaluate patterns of preoperative ultrasound, CT and MRI use among uterine cancer
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patients in Ontario. Secondary objectives included determining an association between CT/MRI imaging and gynecologic oncology consults or surgical staging, and the impact of waiting times for surgery in women with this disease. Methods This is a population-based study using data at the Institute of Clinical Evaluative Sciences (ICES), which houses the health records for 12.5 million residents of the province of Ontario, Canada. Ethics approval for this study was obtained through the Research Ethics Board at Sunnybrook Health Sciences Centre. Data sources Data were obtained from the Ontario Cancer Registry (OCR), the Ontario Health Insurance Plan (OHIP), the Registered Persons Database (RPDB), the Canadian Institute for Health Information (CIHI) Discharge Abstract Database (DAD), and the Corporate Physicians' Database (CPD). The OCR has registered all cases of invasive cancer diagnosed in Ontario since 1964 and captures 95% of cancer cases [12]. The OHIP database contains all physician billing records for services provided to Ontario residents since July 1, 1991. Information on radiology imaging and procedures billed for each patient are recorded, along with a service date, provider and institutional identification. The RPDB contains information for all beneficiaries of OHIP since 1991 and includes data such as age, gender, postal code of residence, and vital status. The CIHI-DAD records procedure codes from all inpatient and outpatient hospital admissions, and patient comorbidities at the time of admission to hospital with maximum discrepancy rates of 10% and 11%, respectively, in reported studies on re-abstraction [13]. Comorbidities were classified using Deyo's clinical comorbidity index for administrative databases [14]. The CPD lists all physicians practicing medicine and their specialties in the province of Ontario. Canada's 2001 Census provided data on neighbourhood income quintiles that were linked to individuals using a postal code conversion file to impute socioeconomic status [15]. All databases housed at ICES can be linked by a common unique numeric identifier. Cohort Incident cases of uterine cancer (ICD-9 codes 179 or 182; ICD-10 codes C54 or C55) were identified in the OCR from 1995 to 2005. Exclusion criteria were applied: male gender, age under 18, previous malignancy 3 years prior to diagnosis of endometrial cancer, those with an invalid OHIP number or no recent postal code, any histology other than adenocarcinoma or sarcoma of the uterus, and those who did not have surgery as part of their treatment. Variables Patient variables Variables obtained from OCR included diagnosis date, age at diagnosis, and histology of disease. No staging information is available from this database. Linkage to RPDB and Canadian census data were used for demographics and socioeconomic status, while linkage to CIHI-DAD determined patient comorbidities. Treatment variables This cohort was then linked to the OHIP and CIHI-DAD databases to obtain data regarding investigations and procedures completed 6 months prior to and 6 months after diagnosis of uterine cancer, such as preoperative pelvic or transvaginal ultrasound, preoperative endometrial biopsy (office biopsy and dilatation and curettage), preoperative pelvic/abdominal CT and/or MRI, and the date and type
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of surgical procedure. Surgical procedures were classified as “staging” if the procedure included either a pelvic and/or para-aortic node dissection. Linkage to the OHIP and CPD obtained data on consults to gynecologic oncologists, and the specialty of the physician ordering preoperative investigations and performing patient surgeries, respectively. Analysis The group with preoperative CT and/or MRI was compared to those without preoperative CT and/or MRI to see if use varied according to age, comorbidities, socioeconomic status, location of dwelling (rural or urban), or tumor histology. The rates of CT and MRI use were calculated over time. The time from investigation to final surgery was calculated for those with ultrasound, CT or MRI; time to surgery for those with preoperative imaging were compared to those without. Finally, the two groups were compared to see if there was an association with preoperative imaging and consults to gynecologic oncology, or to surgical staging. Statistical analysis was performed using SAS 9.1. The Student t-test was used for comparison of continuous data, and the Chi-Squared test for categorical data, with 95% confidence intervals. Multivariate logistic regression analysis was performed to determine independent factors associated with performance of imaging. Clinically important variables that were thought to potentially influence preoperative imaging were chosen a priori and entered into the model. A two-tailed p b 0.05 was considered statistically significant. Results 14,665 women were diagnosed with uterine cancer in Ontario between 1995 and 2005. After excluding patients with histology other than adenocarcinoma or sarcoma (n = 981) and patients who did not have surgery as part of their management (n = 1162), 12,522 women were eligible for analysis. The mean age was 63.4 years, with the majority (87.5%) over the age of 50, and presumably postmenopausal. 83.7% of patients had endometrioid type histology. The OCR did not include details regarding grade. 16.3% were classified as having high risk histology, such as serous, clear cell, undifferentiated, or sarcoma. The majority of patients (81.8%) had at least a total abdominal hysterectomy and bilateral salpingo-oophorectomy as part of their treatment. 16.2% of patients underwent a staging procedure which included pelvic and/or para-aortic lymphadenectomy. The baseline characteristics of this cohort are presented in Table 1. Preoperative investigations 73% of the cohort (n = 9145) had a preoperative ultrasound, with the majority done prior to obtaining a histologic diagnosis of cancer (n = 8458, 92.5%). The median time between ultrasound and a biopsyproven diagnosis was 47 days. Most of these ultrasounds were ordered by non-gynecologists (73.3%); 67.4% (n = 5540) were family physicians and 26.7% (n = 2197) were gynecologists. 73.5% (n = 9198) had an endometrial biopsy or dilatation and curettage done prior to surgery resulting in a diagnosis of uterine cancer, while 23.2% (n = 2906) were diagnosed with a malignancy from the pathologic specimen obtained from definitive surgery. 1148 patients (9.2%) had a preoperative CT or MRI as part of their preoperative investigations. Preoperative CT and/or MRI use The characteristics of the group with preoperative CT and/or MRI were compared to those without preoperative CT and/or MRI to determine if any variables were associated with obtaining these
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Table 1 Baseline characteristics.
Table 3 Predictors of preoperative imaging by multivariate regression analysis.
Variable
N (total = 12,522)
Age N 50 years ≤ 50 years Comorbidity (Charlson score) 0 ≥1 Residencea Urban Rural Income quintileb 1 (lowest) 2 3 4 5 Unknown Histology Endometrioid Serous/clear cell/sarcoma Surgery Hysterectomy (Hyst)/BSO Hyst/BSO + nodesc Laparotomy (“open/close”)
%
10,956 1566
87.5 12.5
11,100 1422
88.6 11.4
10,564 1945
84.5 15.6
2186 2469 2461 2550 2629 227
17.5 19.7 19.7 20.4 21.0 1.8
10,480 2042
83.7 16.3
10,239 2027 256
81.8 16.2 2.0
Variable
Hazard ratio
95% Confidence intervals
Age Comorbidity (Charlson score ≥1) Urban residence Income quintilea 1 (lowest) 2 3 4 5 Histology (high riskb)
1.01 1.23 1.31
1.00–1.01 1.03–1.48 1.09–1.57
1.23 1.03 0.98 0.92 1.0 2.91
1.02–1.50 0.85–1.25 0.81–1.20 0.76–1.13 – 2.54–3.32 (p b 0.0001)
a b
Reference category is income quintile 5, represented by HR 1.0. Papillary serous, clear cell, undifferentiated, or sarcoma.
ordered by gynecologic oncologists. The majority of CT scans (50%) were ordered by non-gynecologists, 42% of whom were family physicians. Among MRI scans ordered, 54% were ordered by gynecologic oncologists, while 22% were general gynecologists and 24% were non-gynecologists (Fig. 2). Association with consults to gynecologic oncology and staging
BSO = bilateral salpingo-oophorectomy. a Missing variable in 13. b Missing variable in 203. c Pelvic +/− para-aortic lymphadenectomy.
images. There were no clinically significant differences in the two groups with regard to age, comorbidities, region of dwelling or socioeconomic status (Table 2). However, there was a higher proportion of patients in the preoperative imaging group who had high risk tumor histology, namely serous, clear cell, undifferentiated type, and sarcomas (33.5% vs 14.6%, p b 0.0001). When these same factors were analyzed by multivariate regression analysis, high risk tumor histology was the only independent prognostic factor associated with preoperative imaging that was both statistically and clinically significant (odds ratio [OR] 2.91, 95% confidence intervals [CI] 2.54–3.32, p b 0.0001). Although other factors were statistically significant in this analysis, the odds ratios of these variables were close to 1.0, and therefore these results likely reflect the large sample size of this cohort (Table 3). The rate of CT and MRI use was calculated between 1995 and 2005. There was a 4.5-fold increase in CT use over 10 years. Meanwhile, there was a 10.6-fold increase in MRI use over the same time period (Fig. 1). Of all the patients receiving CT or MRI, 10% of patients received both CT and MRI preoperatively. The physician ordering the imaging test was identified for 80% of CT scans (n = 846) and 71% of MRIs (n = 145). Among the CT scans ordered, 35% were ordered by general gynecologists, while 15% were
Overall, 31.4% had a consultation with a gynecologic oncologist, and 19% had their surgical procedure done by a gynecologic oncologist. Staging, which was defined as having a pelvic and/or para-aortic node dissection, was completed in 16.2% of patients. There was a significant difference in the number of consultations with a gynecologic oncologist, with 52.7% in the preoperative imaging group compared to 29.2% in the non-preoperative imaging group (p b 0.0001). Additionally, there was a significant difference in the proportion of those who had a staging procedure; 37.2% in the preoperative imaging group had a pelvic and/or para-aortic node dissection, compared to 14.1% in the non-preoperative imaging group (p b 0.0001). However, from this data we are unable to determine the timing of the imaging test in relation to the consultation, and whether the imaging influenced the decision to surgically stage. Time from diagnosis to surgery The median time from having an ultrasound to having a biopsyproven histologic diagnosis of cancer was 47 days. The median time from histologic diagnosis to definitive surgery was 34 days. Using ultrasound as a surrogate for seeking medical attention because of concern of vaginal bleeding, the median time from ultrasound to surgery was 81 days, or 11.6 weeks. When comparing the groups with and without preoperative CT/ MRI, the median time from biopsy-proven histologic diagnosis of
Table 2 Comparison of characteristics of those with and without preoperative CT +/− MRI. Variable
Preop CT +/− MRI (n = 1148)
No preop CT +/− MRI (n = 11,374)
Age (years) Comorbidity ≥1 (Charlson score) Urban residence Income quintile 1 (lowest) 2 3 4 5 Histology (high riska)
64.6 13.8% 87.4%
63.3 11.1% 84.2%
21.0% 19.8% 18.9% 18.3% 20.4% 33.5%
17.1% 19.8% 19.8% 20.6% 21.1% 14.6%b
a b
Papillary serous, clear cell, undifferentiated, or sarcoma. p b 0.0001.
Fig. 1. Rate of CT and MRI use in uterine cancer patients over time.
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Fig. 2. Physicians ordering preoperative CT and MRI scans.
cancer to surgery was 35 days in the group without preoperative imaging, and 49 days in the group with preoperative imaging. In other words, the time from histologic diagnosis to definitive surgery was 2 weeks longer if a CT or MRI was obtained preoperatively. This was a statistically significant difference (p b 0.0001). Discussion This study demonstrates that pre-diagnosis ultrasound is commonplace and the rate of preoperative CT and MRI use for uterine cancer has increased significantly over the past 10 years. Compared to all cancer patients with a previously reported 2.3-fold increase in CT use and 4.6-fold increase in MRI use [11], in uterine malignancies the rates were twice as high with a 4.6-fold increase in CT and 10.6-fold increase in MRI. These increases are difficult to justify given the questionable utility of these preoperative tests. Depth of myometrial invasion is a known risk factor for lymph node metastasis, where tumor invasion into the outer half of the myometrium can result in positive nodes in 25%, compared to 1% for tumors isolated to the endometrium [2]. Some practitioners believe preoperative CT/MRI may be warranted to predict for myometrial invasion and triage those who require surgical staging. However, intraoperative gross visual inspection of the bivalved uterus has a sensitivity of 84%, specificity of 91% [16], and an overall accuracy rate of 85% [17,18], similar to the accuracy rate for predicting myometrial invasion by MRI [17]. Likewise, MRI provides a minimal additional benefit when compared to intraoperative frozen section [19]. Furthermore, Zerbe et al. [20] reported the sensitivity of CT scans in predicting any degree of myometrial invasion, lymph node or cervical involvement to be only 50–60%. Therefore, it is difficult to justify preoperative imaging to predict myometrial invasion when the intraoperative assessment has at least a similar accuracy to MRI and improved sensitivity compared to CT. Some physicians may order CT/MRI in case imaging alters management. In a study by Connor et al. [4], preoperative CT scans were done in 15% of patients with uterine malignancies. Of the 75 patients, only six (8%) had treatments modified based on CT scans, of which two (3%) had advanced disease prohibiting primary surgery [4]. More recently, Bansal et al. [8] reported on 250 patients who underwent preoperative CT scans for uterine cancer. In those with endometrioid histology, 7–9% had findings on imaging suggesting metastases, but only 4% had management altered. In our study, the cohort only consisted of uterine cancer patients who had surgery as part of their treatment. On exploratory analysis, the 1162 patients who did not have surgery and were excluded from the cohort were compared to the surgery group. Median age was 69 years compared to 63 years (p b 0.0001), and the comorbidity index
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was higher in 25%, versus 11% in the surgery group (p b 0.0001). Furthermore, of the 1162 patients who did not have surgery, 48% had a CT/MRI as part of their investigations, but it could not be determined when the imaging was done in relation to the decision to have surgery, or whether the imaging was done for monitoring during subsequent treatment. The study design prohibited knowing the results from the imaging tests. Therefore, we cannot predict how many patients had treatment altered by these tests. Based on previously reported studies [4,8], this number is likely small. Additionally, it has been reported that an expenditure of $17,622 (US) for CT imaging is required to alter the management of one patient [8]. In a publicly funded health care system, the routine use of these tests with their associated costs cannot be supported. Our study demonstrated that the presence of serous, clear cell, undifferentiated carcinoma or sarcoma was associated with increased CT and MRI use. Since these histologies have a greater risk of peritoneal and lymphatic dissemination, it is not surprising that the imaging rate is higher in this group. Bansal et al. [8] also reported that CT scans altered management in 11% of serous or clear cell carcinomas and 13% of sarcomas, which suggests the use of CT/MRI for high risk histology may be more useful compared to those with endometrioid histology. However, it is also arguable that if staging will be completed in this high risk group regardless of its findings, the goal of imaging is questionable. There are several limitations to this study. The indication for the CT/MRI is not available from the databases. Therefore, CT/MRIs done in the preceding 6 months for reasons other than their uterine cancer work-up could result in an overestimation of imaging tests. Alternatively, MRI scans performed for inpatient scans have no OHIP billing and therefore the rate of MRI use could be underestimated. Additionally, we cannot determine whether the association of preoperative CT/MRI with a higher rate of gynecologic oncology consults and lymphadenectomies is a result of causation. It is not possible from our methods to determine if the results from the imaging led to a referral to gynecologic oncology and the decision to stage, or whether the consult or the decision to stage led to ordering the preoperative imaging. It is likely that these variables are confounded by histology. Those with high risk histologic subtypes received more preoperative imaging, and these same patients were more likely to be referred to a gynecologic oncologist for consultation and subsequent surgical staging. The results of the CT and MRI scans would have to be known to determine whether the imaging had an effect on management. Further work with the individual chart review of all cases across the province would be required to describe the true relationship among preoperative imaging, consults to gynecologic oncology, and surgical staging. The absence of stage of disease from the databases is also a limitation. We cannot determine whether there were a higher proportion of patients with Stage III or IV disease in the non-operative group or whether imaging had any influence in this decision. However, the number of patients who present with peritoneal carcinomatosis from uterine cancer who cannot be managed with surgery is likely to be small. We also cannot determine whether imaging was done for Stage II disease if there was suspicion of cervical involvement on clinical exam, and whether imaging influenced management. Ideally, it would be useful to correlate stage data with what was found on imaging results, but that is not possible with this population study based on the absence of such information from the databases. Furthermore, the reason for ordering the tests is unknown. The majority of physicians ordering CT scans were non-gynecologists, 42% of which were family physicians. In an era where CT scans are increasingly prevalent, perhaps non-gynecologists presume that ordering a CT is helpful for the subspecialist managing the disease. Alternatively, it is unknown whether gynecologic oncologists are requesting a CT scan to be ordered prior to consultation, although, arguably, the imaging rate for gynecologic oncologists should be
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lower since they are trained to perform lymphadenectomies. Given the limited utility of preoperative CT scans in this disease, development of guidelines for tests in uterine cancer patients would be helpful for all physicians involved in the care of these women. Finally, this study demonstrated significant delays during the preoperative work-up for patients with uterine cancer. The majority of women with postmenopausal bleeding had an ultrasound by their family physician prior to having an endometrial biopsy by a gynecologist. The cumulative wait times for the ultrasound and consult to a gynecologist, and the additional wait time for surgery resulted in a median of 11.6 weeks between symptoms and definitive surgery. This time is an underestimate because it does not account for the time the patient waited for the ultrasound. An ultrasound in a woman with postmenopausal bleeding should not be the first step in management, given that an endometrial biopsy is needed regardless of the thickness of the endometrial lining [21]. In order to improve delays in diagnosis and treatment, further dissemination of information is needed for both patients and physicians that the first test for postmenopausal bleeding is an endometrial biopsy. The median time from histologic diagnosis to surgery for those with preoperative CT/MRI scans was 2 weeks longer than those without these preoperative tests. For the subset which had both CT and MRI preoperatively, this could potentially be a longer delay. Although we cannot confirm whether the longer waiting time is caused by the imaging studies, or whether the imaging is done while awaiting surgery delayed for other reasons, the delay is another reason to deter from a preoperative CT/MRI, especially when management is rarely altered by these tests. The routine use of CT/MRI scans preoperatively in uterine cancer is of limited value and should not be universally used for all patients diagnosed with this disease. The rate of CT and MRI use in uterine cancer patients has increased twice that of cancer patients in general. This is the first study to evaluate the pattern of CT and MRI use in uterine cancer using administrative databases, and represents what is occurring in our health care system. This study generates questions regarding the indications for CT or MRI use in this disease. Further guidelines should be developed for imaging tests in uterine cancer, especially since its use is associated with a delay in surgery. Conflict of interest statement There are no conflicts of interest declared.
Acknowledgments This was presented at the International Gynecologic Cancer Society 12th Biennial Meeting, October 2008, Bangkok, Thailand. Lisa Barbera, MD, is an Ontario Ministry of Health and Long Term Care Career Scientist.
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