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Should surgeons as well as radiologists report mammograms in symptomatic patients?
The Breast (2001) 10, 140–142 # 2000 Harcourt Publishers Ltd doi:10.1054/brst.2000.0216, available online at http://www.idealibrary.com on
ORIGINAL ARTICLE
Should surgeons as well as radiologists report mammograms in symptomatic patients? R. Vidya and J. M. Dixon Edinburgh Breast Unit, Western General Hospital, Edinburgh, UK S U M M A R Y. This study compared the accuracy of interpretation by surgeons and radiologists of 1053 women who had two view mammography and a histological or cytological diagnosis of benign or malignant breast disease. Patients with large or locally advanced breast cancers who had definite clinical findings where radiology was not required to make a diagnosis were excluded. The sensitivity for radiologists was non-significantly greater (81%) than surgeons (78%), but specificity and positive predictive value was identical in the two groups of readers. Combining the reports of the radiologists and surgeons increased sensitivity to 85.4% which is a significant increase in the sensitivity of the radiologist alone, P=0.02. This study indicates that symptomatic mammograms should be read by surgeons as well as radiologists. # 2000 Harcourt Publishers Ltd
current study. The clinic protocol was that all patients were seen in the clinic by two doctors. The first doctor was a senior house officer, a junior specialist registrar or a clinical assistant and the second doctor was an experienced breast surgeon, either a staff grade surgeon or more commonly a consultant surgeon. Mammograms were performed either immediately prior to the patient attending the clinic or were ordered by the first doctor. For all patients included in this study mammograms were available to the surgeon prior to them seeing the patient. The surgeon then reported the mammograms having received the history from the first doctor. The patient was then examined by the surgeon and then the mammogram request form was completed with full details of the history and clinical findings being recorded. This study is a selective series of patients with solid masses as all patients with cysts were excluded because when a cyst was aspirated in the clinic this was made clear to the radiologist on the mammogram request form. Also excluded were patients with very large or locally advanced breast cancers who had such definite clinical findings that radiology was not required to make a specific diagnosis. This study therefore concentrates on those solid lesions where the surgeon was looking for assistance from mammography to help establish a definitive diagnosis.
INTRODUCTION Mammography is a sensitive method for detecting breast abnormalities although its specificity is low.1,2 When screening films are read by two radiologists the number of cancers detected increases by almost 10% yet mammograms of symptomatic patients are usually read and reported by a single radiologist. Previous studies have suggested that non-radiologists can read mammograms with the same accuracy as radiologists.3 The aim of the present study was to investigate the value of experienced breast surgeons who had no training in radiology interpreting mammograms of symptomatic patients.
PATIENTS, MATERIALS AND METHODS This is a retrospective analysis of a cohort of patients attending the Breast Unit at the Western General Hospital prior to the introduction of one stop clinics. Patients seen during 1997 and 1998 were included in the Address correspondence to: Mr J. M. Dixon, Consultant Surgeon and Senior Lecturer, Academic Office, Edinburgh Breast Unit, Western General Hospital, Edinburgh EH4 2XU, UK. Tel.: +44 (0) 131 537 2643; Fax: +44 (0) 131 537 2653; E-mail: [email protected] Published online: 29 November 2000
140
Should surgeons as well as radiologists report mammograms in symptomatic patients? One thousand and fifty three women were identified who had two-view mammography and had a histological or cytological diagnosis of benign or malignant disease. Of the 1053 cases, 567 were diagnosed as malignant and 486 were solid benign lesions. Four consultant surgeons and one staff grade and four consultant radiologists reported mammograms in this study. All the radiologists had at least 10 years’ experience in reading mammograms. Of the consultant surgeons, one had been a consultant for over 10 years at the start of the study, one six years’ one three years and the other one year. The staff grade surgeon had been in post for three years. Mammograms were reported on the standard 5 point scale; R1=normal, R2=benign, R3=probably benign, R4=probably malignant, R5=malignant. When considering sensitivity R4 or R5 mammograms were considered. For specificity, R1, R2 and R3 mammograms were considered benign. Positive predictive value was calculated considering only those patients with R5 mammograms and negative predictive value was calculated using those with mammograms reported R1 and R2. The results obtained by surgeons and radiologists were compared using the w2 test. Intra-observer agreement was evaluated by determining the kappa value.
RESULTS Results are shown in Table 1. Table 2 gives values of specificity, sensitivity, positive predictive value and negative predictive value. There was very good agreement in mammographic diagnosis between radiologists and surgeons with a Table 1 Accuracy for interpretation of mammograms by surgeons and radiologists
Cancer Benign
Number
Both surgeon and radiologist correct
Both surgeon and radiologist wrong
Surgeon alone correct
Radiologist alone correct
567 486
415 454
81 15
25 9
46 8
Table 2 Sensitivity, specificity and predictive value for mammographic evaluation by surgeons and radiologists
Sensitivity Specificity Positive predictive value Negative predictive value
Surgeon
Radiologist
78% 95% 95% 78%
81% 95% 95% 81%
141
kappa value of 0.62. There was no significant difference in sensitivity, specificity, positive predictive value or negative predictive value between surgeons and radiologists. Surgeons identified 25 cancers missed by the radiologists. Surgeons thus identified an additional 4.4% of cancers. Thus a combination of the radiologist and the surgeon would have had a sensitivity of 85.4% which is a significant increase in sensitivity over the radiologist alone, P=0.02.
DISCUSSION Mammography complements history and physical examination. Sensitivity varies in different series but in symptomatic practice is in the range of 80–90%. Double reading of screening mammography has been shown to increase sensitivity although it does lead to an increase in the number of women recalled.4–6 When mammograms are reported there is a direct correlation between sensitivity and the experience of the reader.7 Although not trained in reading mammograms, surgeons need to be able to interpret mammographic images before and during needle localization procedures. Studies have shown that when non-radiologists such as surgeons or nurses look at mammograms, their rate of detection of cancer is higher in symptomatic than in screen detected woman.3 These findings suggest that there may be value in surgeons seeing all mammograms of patients presenting to a symptomatic breast clinic. Furthermore, the present study has shown that when surgeons as well as radiologists report mammograms, this can significantly increase sensitivity in a similar but less dramatic way to that reported of double reading of screening mammograms. It is not clear whether double reading of symptomatic mammograms by two radiologists would increase sensitivity even further, but this would have cost implications. Inter-observer agreement between radiologists and surgeons reading mammograms was good as measured by the kappa statistic. One potential criticism of the results of this study could be that the surgeons were influenced in their reports of mammograms by more detailed knowledge of the history and clinical examination. To counter this, the mammogram request form was only completed once the patient had been carefully examined and the radiologist was given detailed information of signs and symptoms. Even with the combination of a surgeon and a radiologist reporting mammograms, the combined sensitivity was only 85%. This study did not include patients with screen detected breast cancer and so the majority of patients were either under the age of 50 or
142
The Breast
over the age of 64. Mammographic sensitivity is known to vary with age and sensitivity is much lower in younger women.8 Also in the present series, large and locally advanced breast cancers were excluded. Nonetheless, this series does represent a group of patients where the surgeons needs assistance in diagnosing a solid mass lesion and the present study has shown that in this selected group of patients, mammography has limited sensitivity. Thus mammography is not particularly useful in helping establish a diagnosis in patients with discrete lumps but it is useful for screening and detecting other lesions within the breast. For a discrete mass, a combination of ultrasound with fine needle aspiration cytology or core biopsy performed freehand or in small lesions image guided are the investigations of choice. References 1. Harvey J A, Fajardo L L, Innis C A. Previous mammograms in patients with impalpable breast carcinoma: retrospective vs blinded
2. 3. 4. 5. 6. 7. 8.
interpretation. American Journal of Roentgenology 1993; 161: 1167–1172. Heywang-Kobrunner S H, Schreer I, Dershaw D D. Diagnostic breast imaging. Tuttgart Thiene, 1997: 209–220. George W D, Sellwood R A, Asbury D, Hartley G. Role of non-medical staff in screening for breast cancer. B M J 1980; 280: 147–149. Anttinen I, Pamilo M, Soiva M, Roiha M. Double reading of mammography screening films – one radiologist or two? Clin Radiol 1993; 48: 414–421. Anderson E D C, Muir B B, Walsh J S, Kirkpatrick A E. The efficacy of double reading mammograms in breast screening. Clin Radiol 1994; 41: 248–251. Denton E R E, Field S. Just how valuable is double reporting in screening mammography? Royal College of Radiologists 1997; 52: 466–458. Warren R, Duffy S. Comparison of single reading with double reading of mammograms and change in effectiveness with experience. B J Radio 1995; 68: 958–962. Dixon J M, Anderson T J, Lamb J, Nixon S J and Forrest A P M. Fine needle aspiration cytology in relationship to clinical examination and mammography in the diagnosis of a solid breast mass. B J Surg 1984; 71: 593–596.
ORIGINAL ARTICLE
Should surgeons as well as radiologists report mammograms in symptomatic patients? R. Vidya and J. M. Dixon Edinburgh Breast Unit, Western General Hospital, Edinburgh, UK S U M M A R Y. This study compared the accuracy of interpretation by surgeons and radiologists of 1053 women who had two view mammography and a histological or cytological diagnosis of benign or malignant breast disease. Patients with large or locally advanced breast cancers who had definite clinical findings where radiology was not required to make a diagnosis were excluded. The sensitivity for radiologists was non-significantly greater (81%) than surgeons (78%), but specificity and positive predictive value was identical in the two groups of readers. Combining the reports of the radiologists and surgeons increased sensitivity to 85.4% which is a significant increase in the sensitivity of the radiologist alone, P=0.02. This study indicates that symptomatic mammograms should be read by surgeons as well as radiologists. # 2000 Harcourt Publishers Ltd
current study. The clinic protocol was that all patients were seen in the clinic by two doctors. The first doctor was a senior house officer, a junior specialist registrar or a clinical assistant and the second doctor was an experienced breast surgeon, either a staff grade surgeon or more commonly a consultant surgeon. Mammograms were performed either immediately prior to the patient attending the clinic or were ordered by the first doctor. For all patients included in this study mammograms were available to the surgeon prior to them seeing the patient. The surgeon then reported the mammograms having received the history from the first doctor. The patient was then examined by the surgeon and then the mammogram request form was completed with full details of the history and clinical findings being recorded. This study is a selective series of patients with solid masses as all patients with cysts were excluded because when a cyst was aspirated in the clinic this was made clear to the radiologist on the mammogram request form. Also excluded were patients with very large or locally advanced breast cancers who had such definite clinical findings that radiology was not required to make a specific diagnosis. This study therefore concentrates on those solid lesions where the surgeon was looking for assistance from mammography to help establish a definitive diagnosis.
INTRODUCTION Mammography is a sensitive method for detecting breast abnormalities although its specificity is low.1,2 When screening films are read by two radiologists the number of cancers detected increases by almost 10% yet mammograms of symptomatic patients are usually read and reported by a single radiologist. Previous studies have suggested that non-radiologists can read mammograms with the same accuracy as radiologists.3 The aim of the present study was to investigate the value of experienced breast surgeons who had no training in radiology interpreting mammograms of symptomatic patients.
PATIENTS, MATERIALS AND METHODS This is a retrospective analysis of a cohort of patients attending the Breast Unit at the Western General Hospital prior to the introduction of one stop clinics. Patients seen during 1997 and 1998 were included in the Address correspondence to: Mr J. M. Dixon, Consultant Surgeon and Senior Lecturer, Academic Office, Edinburgh Breast Unit, Western General Hospital, Edinburgh EH4 2XU, UK. Tel.: +44 (0) 131 537 2643; Fax: +44 (0) 131 537 2653; E-mail: [email protected] Published online: 29 November 2000
140
Should surgeons as well as radiologists report mammograms in symptomatic patients? One thousand and fifty three women were identified who had two-view mammography and had a histological or cytological diagnosis of benign or malignant disease. Of the 1053 cases, 567 were diagnosed as malignant and 486 were solid benign lesions. Four consultant surgeons and one staff grade and four consultant radiologists reported mammograms in this study. All the radiologists had at least 10 years’ experience in reading mammograms. Of the consultant surgeons, one had been a consultant for over 10 years at the start of the study, one six years’ one three years and the other one year. The staff grade surgeon had been in post for three years. Mammograms were reported on the standard 5 point scale; R1=normal, R2=benign, R3=probably benign, R4=probably malignant, R5=malignant. When considering sensitivity R4 or R5 mammograms were considered. For specificity, R1, R2 and R3 mammograms were considered benign. Positive predictive value was calculated considering only those patients with R5 mammograms and negative predictive value was calculated using those with mammograms reported R1 and R2. The results obtained by surgeons and radiologists were compared using the w2 test. Intra-observer agreement was evaluated by determining the kappa value.
RESULTS Results are shown in Table 1. Table 2 gives values of specificity, sensitivity, positive predictive value and negative predictive value. There was very good agreement in mammographic diagnosis between radiologists and surgeons with a Table 1 Accuracy for interpretation of mammograms by surgeons and radiologists
Cancer Benign
Number
Both surgeon and radiologist correct
Both surgeon and radiologist wrong
Surgeon alone correct
Radiologist alone correct
567 486
415 454
81 15
25 9
46 8
Table 2 Sensitivity, specificity and predictive value for mammographic evaluation by surgeons and radiologists
Sensitivity Specificity Positive predictive value Negative predictive value
Surgeon
Radiologist
78% 95% 95% 78%
81% 95% 95% 81%
141
kappa value of 0.62. There was no significant difference in sensitivity, specificity, positive predictive value or negative predictive value between surgeons and radiologists. Surgeons identified 25 cancers missed by the radiologists. Surgeons thus identified an additional 4.4% of cancers. Thus a combination of the radiologist and the surgeon would have had a sensitivity of 85.4% which is a significant increase in sensitivity over the radiologist alone, P=0.02.
DISCUSSION Mammography complements history and physical examination. Sensitivity varies in different series but in symptomatic practice is in the range of 80–90%. Double reading of screening mammography has been shown to increase sensitivity although it does lead to an increase in the number of women recalled.4–6 When mammograms are reported there is a direct correlation between sensitivity and the experience of the reader.7 Although not trained in reading mammograms, surgeons need to be able to interpret mammographic images before and during needle localization procedures. Studies have shown that when non-radiologists such as surgeons or nurses look at mammograms, their rate of detection of cancer is higher in symptomatic than in screen detected woman.3 These findings suggest that there may be value in surgeons seeing all mammograms of patients presenting to a symptomatic breast clinic. Furthermore, the present study has shown that when surgeons as well as radiologists report mammograms, this can significantly increase sensitivity in a similar but less dramatic way to that reported of double reading of screening mammograms. It is not clear whether double reading of symptomatic mammograms by two radiologists would increase sensitivity even further, but this would have cost implications. Inter-observer agreement between radiologists and surgeons reading mammograms was good as measured by the kappa statistic. One potential criticism of the results of this study could be that the surgeons were influenced in their reports of mammograms by more detailed knowledge of the history and clinical examination. To counter this, the mammogram request form was only completed once the patient had been carefully examined and the radiologist was given detailed information of signs and symptoms. Even with the combination of a surgeon and a radiologist reporting mammograms, the combined sensitivity was only 85%. This study did not include patients with screen detected breast cancer and so the majority of patients were either under the age of 50 or
142
The Breast
over the age of 64. Mammographic sensitivity is known to vary with age and sensitivity is much lower in younger women.8 Also in the present series, large and locally advanced breast cancers were excluded. Nonetheless, this series does represent a group of patients where the surgeons needs assistance in diagnosing a solid mass lesion and the present study has shown that in this selected group of patients, mammography has limited sensitivity. Thus mammography is not particularly useful in helping establish a diagnosis in patients with discrete lumps but it is useful for screening and detecting other lesions within the breast. For a discrete mass, a combination of ultrasound with fine needle aspiration cytology or core biopsy performed freehand or in small lesions image guided are the investigations of choice. References 1. Harvey J A, Fajardo L L, Innis C A. Previous mammograms in patients with impalpable breast carcinoma: retrospective vs blinded
2. 3. 4. 5. 6. 7. 8.
interpretation. American Journal of Roentgenology 1993; 161: 1167–1172. Heywang-Kobrunner S H, Schreer I, Dershaw D D. Diagnostic breast imaging. Tuttgart Thiene, 1997: 209–220. George W D, Sellwood R A, Asbury D, Hartley G. Role of non-medical staff in screening for breast cancer. B M J 1980; 280: 147–149. Anttinen I, Pamilo M, Soiva M, Roiha M. Double reading of mammography screening films – one radiologist or two? Clin Radiol 1993; 48: 414–421. Anderson E D C, Muir B B, Walsh J S, Kirkpatrick A E. The efficacy of double reading mammograms in breast screening. Clin Radiol 1994; 41: 248–251. Denton E R E, Field S. Just how valuable is double reporting in screening mammography? Royal College of Radiologists 1997; 52: 466–458. Warren R, Duffy S. Comparison of single reading with double reading of mammograms and change in effectiveness with experience. B J Radio 1995; 68: 958–962. Dixon J M, Anderson T J, Lamb J, Nixon S J and Forrest A P M. Fine needle aspiration cytology in relationship to clinical examination and mammography in the diagnosis of a solid breast mass. B J Surg 1984; 71: 593–596.