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Tu1494 Clinicopathological Characteristics of Interval Cancer Compared to Sporadic Colorectal Cancer
Abstracts
Tu1493 Adenoma Detection Rate in Asymptomatic Japanese Patients on Initial Colonoscopy Kiyoshi Mizuno*1, Hideki Fukuoka2, Atsushi Hirai2, Takahiro Shimodaira2, Jouji Kato2, Osamu Hara2 1 Internal Medicine, Nagoya Toei Clinic, Nagoya, Japan; 2Department of gastroenterology, Kizankai Memorial Hospital, Iida, Japan Background: Adenoma detection rate (ADR) is the accepted marker of colonoscopy quality. Current guidelines from Western countries recommend colonoscopy for colorectal cancer (CRC) screening in age over 50 years. But in recent years several studies reported potential need of screening in people under 50. At this moment prevalence of colorectal neoplasia for younger generation is not fully elucidated yet. The aim of this study was to estimate the prevalence of colorectal adenoma, advanced adenoma and adenocarcinoma in asymptomatic Japanese focusing on age under 50. Methods: We reviewed the endoscopic and pathological records of individuals age 20 to 85 (mean age 48.2 years) who underwent first-time colonoscopy from January 2004 to December 2012 at our clinic. Colonoscopies were performed for screening or positive fecal immunochemical testing (FIT). Overall adenoma detection rate was calculated. The prevalence of adenoma, advanced adenoma and invasive cancer were compared in both screening and FIT group and statistically analysed. Results: Of 7842 colonoscopy performed during the period, 2982 first time colonoscopy patients were evaluated. 72.6% (2165/2982) were men. 690 (23.1%) were in the screening group, while 2292 (76.9%) were in the positive FIT group. Overall adenoma detection rate was 24.3% (24.2% for men and 13% for women). The ADR for screening colonoscopy was 15.6% (17.5% for men and 8.2% for women), whereas the ADR for positive FIT patients was 27% (31.3% for men and 17% for women). The ADR for patients with age !40, 40-49 years, 50-59 years, O60 years were 7.06% (7.45% for men and 6.25% for women), 21,4% (25.3% for men and 10.6% for women), 32,5% (37.9% for men and 16.6% for women), 38.7% (39.1% for men and 37.6% for women), respectively. Compared to the age !40, the ORs and 95%CIs for men in each age group were 4.22, 2.86-6.21 (40-49 years), 7.57, 5.19-11.03 (50-59 years), 7.98, 5.31-12.0 (O60 years), and for women 1.78, 0.09-3.53 (40-49 years), 2.98, 1.57-5.63 (50-59 years), 9.03, 4.74-17.2 (O60 years) respectively. Conclusions: Prevalences of colonic neoplasia is much higher in men and increases with age. In these observation ADR for men between the ages of 40 to 49 years is substantially high compared to the ages under 40 years in both screening and positive FIT group. Over the age of 50 years ADRs were similar to those reported previously. This study suggests screening colonoscopy for men over the age of 40 years should be considered.
Tu1494 Clinicopathological Characteristics of Interval Cancer Compared to Sporadic Colorectal Cancer BUN Kim*, Soo Jung Park, Jae Hee Cheon, Tae IL. Kim, Won Ho Kim, Sung Pil Hong Institute of Gastroenterology, Department of internal medicine, Yonsei University College of Medicine, Seoul, Republic of Korea Background and aim: Colonoscopy has been widely performed to prevent colorectal cancers (CRCs). Because colonoscopy detect and remove adenoma effectively, surveillance colonoscopy is recommended with an interval according to the findings of index colonoscopy. However, recent studies reported the occurrence of CRCs shortly after colonoscopy. The aim of the present study was to compare the clinicopathological characteristics of interval cancers with sporadic CRCs. Method: From Jan. 2005 to Oct. 2012, 8610 patients received colonoscopy more than twice with at least 6 months interval at a tertiary academic hospital. Among them, 31 patients (0.36%) developed CRCs, which were referred to interval cancers. In the opportunistic screening center, 3785 subjects with over 50 year old received screening colonoscopy and 29 patients (0.77%) were diagnosed with CRCs. Clinical and pathological findings were reviewed retrospectively. Results: Among 31 patients with interval cancer, 12 (38.7%) were classified into new CRCs, 13 (41.9%) were missing CRCs, 3 (9.7%) were incomplete adenoma resection, and 3 (9.7%) were other categories, such as incomplete colonic intubation (2) and poor bowel preparation (1). The median interval between previous colonoscopy and the diagnosis of the interval cancer was 31 months. The median age of interval cancers and sporadic CRCs were 65 and 63, respectively (PZ0.437). Female tended to be more dominant in the interval cancer than sporadic CRCs (41.9% vs. 20.7%; PZ0.077). Other factors, such as family history of CRCs, aspirin use, smoking, and alcohol drinking were not different between the 2 groups. Interval cancers were significantly more prevalent in right colon than sporadic CRCs (48.4% vs. 17.2%; PZ0.011). When comparing morphological classification, B-0 type were significantly more common in interval cancers than sporadic CRCs (32.3% vs. 3.4%; PZ0.008). B-II and B-III types were most common morphological class in sporadic CRCs. Tumor size, grade, stage, and initial CEA level were not different between the 2 groups. Conclusion: Interval cancers have distinct clinicopathological
AB454 GASTROINTESTINAL ENDOSCOPY Volume 79, No. 5S : 2014
characteristics compared to sporadic colorectal cancers. Further genetic studies are mandatory to validate the different carcinogenesis of interval cancers.
Tu1495 Cost-Effectiveness Analysis of Different Surveillance Strategies After High-Risk Adenoma Excision Pedro Zapater, Rodrigo Jover* Hospital General Universitario de Alicante, Alicante, Spain Background & Aims: Guidelines recommend that patients with high-risk colon adenomas undergo surveillance colonoscopy at 3 years after excision. However, evidences supporting this interval recommendation are scarce and low-quality. The purpose of this study was to compare the cost-effectiveness of this strategy versus a strategy with longer surveillance intervals. Methods: We developed a Markov model to compare the current recommendation with colonoscopy at 3 years and subsequent colonoscopy at 5 years if no lesions or low-risk lesions are found versus a longer interval strategy based in colonoscopy at 5 years followed by subsequent colonoscopy at 10 years. We modelled a cohort of 50-year-old patients with newly diagnosed high-risk adenomas. Surveillance colonoscopies were performed until the age of 80 and patients were followed until death. Costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs) were measured. The analysis was performed using "R" software (version 2.13.1) Results: The 5 years surveillance interval supposes a saving of 158.992 colonoscopies in a 100.000 high risk-adenoma population with a cost difference of 55.329.216 €. However, this longer interval strategy results in a difference of 2.083 more colorectal cancer (CRC) cases and 562 more CRC deaths in the same population. The 3 years strategy had an average lifetime cost (ALTC) of 2,263€ whereas in the 5 years strategy this ALTC was 2,348€. The average QALYs in the 3 years surveillance arm was 21.0, and in the 5 years surveillance it was 21.7. Both strategies showed a similar cost-effectiveness rate with an ICER of 121€ per QALY favouring the 5 years strategy. The probabilistic sensitivity analysis confirmed the lack of differences between both strategies. Conclusions: A model with longer interval surveillance colonoscopies after high-risk adenoma excision shows a similar cost-effectiveness than current recommendations. This longer interval strategy would suppose a high reduction in the number of colonoscopies performed with the consequent gain in colonoscopic capacity. Studies comparing both strategies should be encouraged.
Tu1496 Missed Polyps Are Common in Patients Referred for Endoscopic Resection of Colon Polyps Rajesh N. Keswani*1, Roy M. Soetikno2, Tonya Kaltenbach2 1 Medicine, Northwestern University, Chicago, IL; 2Veteran’s Affairs Palo Alto Health Care System, Palo Alto, CA Introduction: Patients with complex colon polyps may be referred to a specialist in endoscopic resection (ER), presumably with all synchronous polyps identified or removed. The primary aim was to determine the polyp "miss" rate identified at ER. The secondary aim was to determine the association of referring physician adenoma detection rate (ADR) with polyp miss rate. Methods: Review of available data collected in two prospective colon ER databases was performed over a 4-year period (2008-2012). We included patients who had their index colonoscopy performed by a physician with a known ADR. ER of these polyps was performed by 1 of 5 physicians. We defined missed polyps as any polyps identified within one year of index colonoscopy by the ER endoscopist. We defined synchronous polyps as polyps identified (whether or not they were removed) at index colonoscopy by the referring endoscopist. Results: 96 patients (35F/61M) were referred for ER by 21 unique endoscopists. Patient median age was 65 (range 33-86). Median polyp size was 25 mm (range 10-80mm) with the majority (64.6%) of lesions classified as nonpolypoid (Paris O-IIa, IIb, or IIc). In most cases (67.7%), resection of the polyp was not attempted prior to referral. Missed polyps were identified in 67.7% of patients by the ER specialist, with 28.1% of patients harboring polyps O 10 mm in size. Synchronous polyps were identified in 71.9% of patients at index colonoscopy by the referring physician (Table). Sixty-seven patients (70.0%) were referred by physicians with an ADR below their institutional mean. There was a trend towards an increased missed polyp rate by endoscopists with low ADR as compared to those with high ADR (73.1% vs. 55.2%, pZ0.07). There was a similar trend for missed polyps O 10 mm in size and missed nonpolypoid lesions. A single missed adenocarcinoma was identified in a physician with an ADR below institutional mean. There was no difference in polyp miss rate whether synchronous polyps were seen on initial exam (69.6%) or not (63.0%). Endoscopists performing referred ER had ADR above the mean in their respective institutions. Conclusions: The majority of patients referred for ER of complex colon polyps have missed colon polyps, many of which are advanced lesions. Missed lesions appear more common when patients are referred by physicians with lower ADR. After resecting these lesions, referring and referred endoscopists should ensure that patients return for a complete surveillance examination to clear the remaining colon of neoplasia.
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Tu1493 Adenoma Detection Rate in Asymptomatic Japanese Patients on Initial Colonoscopy Kiyoshi Mizuno*1, Hideki Fukuoka2, Atsushi Hirai2, Takahiro Shimodaira2, Jouji Kato2, Osamu Hara2 1 Internal Medicine, Nagoya Toei Clinic, Nagoya, Japan; 2Department of gastroenterology, Kizankai Memorial Hospital, Iida, Japan Background: Adenoma detection rate (ADR) is the accepted marker of colonoscopy quality. Current guidelines from Western countries recommend colonoscopy for colorectal cancer (CRC) screening in age over 50 years. But in recent years several studies reported potential need of screening in people under 50. At this moment prevalence of colorectal neoplasia for younger generation is not fully elucidated yet. The aim of this study was to estimate the prevalence of colorectal adenoma, advanced adenoma and adenocarcinoma in asymptomatic Japanese focusing on age under 50. Methods: We reviewed the endoscopic and pathological records of individuals age 20 to 85 (mean age 48.2 years) who underwent first-time colonoscopy from January 2004 to December 2012 at our clinic. Colonoscopies were performed for screening or positive fecal immunochemical testing (FIT). Overall adenoma detection rate was calculated. The prevalence of adenoma, advanced adenoma and invasive cancer were compared in both screening and FIT group and statistically analysed. Results: Of 7842 colonoscopy performed during the period, 2982 first time colonoscopy patients were evaluated. 72.6% (2165/2982) were men. 690 (23.1%) were in the screening group, while 2292 (76.9%) were in the positive FIT group. Overall adenoma detection rate was 24.3% (24.2% for men and 13% for women). The ADR for screening colonoscopy was 15.6% (17.5% for men and 8.2% for women), whereas the ADR for positive FIT patients was 27% (31.3% for men and 17% for women). The ADR for patients with age !40, 40-49 years, 50-59 years, O60 years were 7.06% (7.45% for men and 6.25% for women), 21,4% (25.3% for men and 10.6% for women), 32,5% (37.9% for men and 16.6% for women), 38.7% (39.1% for men and 37.6% for women), respectively. Compared to the age !40, the ORs and 95%CIs for men in each age group were 4.22, 2.86-6.21 (40-49 years), 7.57, 5.19-11.03 (50-59 years), 7.98, 5.31-12.0 (O60 years), and for women 1.78, 0.09-3.53 (40-49 years), 2.98, 1.57-5.63 (50-59 years), 9.03, 4.74-17.2 (O60 years) respectively. Conclusions: Prevalences of colonic neoplasia is much higher in men and increases with age. In these observation ADR for men between the ages of 40 to 49 years is substantially high compared to the ages under 40 years in both screening and positive FIT group. Over the age of 50 years ADRs were similar to those reported previously. This study suggests screening colonoscopy for men over the age of 40 years should be considered.
Tu1494 Clinicopathological Characteristics of Interval Cancer Compared to Sporadic Colorectal Cancer BUN Kim*, Soo Jung Park, Jae Hee Cheon, Tae IL. Kim, Won Ho Kim, Sung Pil Hong Institute of Gastroenterology, Department of internal medicine, Yonsei University College of Medicine, Seoul, Republic of Korea Background and aim: Colonoscopy has been widely performed to prevent colorectal cancers (CRCs). Because colonoscopy detect and remove adenoma effectively, surveillance colonoscopy is recommended with an interval according to the findings of index colonoscopy. However, recent studies reported the occurrence of CRCs shortly after colonoscopy. The aim of the present study was to compare the clinicopathological characteristics of interval cancers with sporadic CRCs. Method: From Jan. 2005 to Oct. 2012, 8610 patients received colonoscopy more than twice with at least 6 months interval at a tertiary academic hospital. Among them, 31 patients (0.36%) developed CRCs, which were referred to interval cancers. In the opportunistic screening center, 3785 subjects with over 50 year old received screening colonoscopy and 29 patients (0.77%) were diagnosed with CRCs. Clinical and pathological findings were reviewed retrospectively. Results: Among 31 patients with interval cancer, 12 (38.7%) were classified into new CRCs, 13 (41.9%) were missing CRCs, 3 (9.7%) were incomplete adenoma resection, and 3 (9.7%) were other categories, such as incomplete colonic intubation (2) and poor bowel preparation (1). The median interval between previous colonoscopy and the diagnosis of the interval cancer was 31 months. The median age of interval cancers and sporadic CRCs were 65 and 63, respectively (PZ0.437). Female tended to be more dominant in the interval cancer than sporadic CRCs (41.9% vs. 20.7%; PZ0.077). Other factors, such as family history of CRCs, aspirin use, smoking, and alcohol drinking were not different between the 2 groups. Interval cancers were significantly more prevalent in right colon than sporadic CRCs (48.4% vs. 17.2%; PZ0.011). When comparing morphological classification, B-0 type were significantly more common in interval cancers than sporadic CRCs (32.3% vs. 3.4%; PZ0.008). B-II and B-III types were most common morphological class in sporadic CRCs. Tumor size, grade, stage, and initial CEA level were not different between the 2 groups. Conclusion: Interval cancers have distinct clinicopathological
AB454 GASTROINTESTINAL ENDOSCOPY Volume 79, No. 5S : 2014
characteristics compared to sporadic colorectal cancers. Further genetic studies are mandatory to validate the different carcinogenesis of interval cancers.
Tu1495 Cost-Effectiveness Analysis of Different Surveillance Strategies After High-Risk Adenoma Excision Pedro Zapater, Rodrigo Jover* Hospital General Universitario de Alicante, Alicante, Spain Background & Aims: Guidelines recommend that patients with high-risk colon adenomas undergo surveillance colonoscopy at 3 years after excision. However, evidences supporting this interval recommendation are scarce and low-quality. The purpose of this study was to compare the cost-effectiveness of this strategy versus a strategy with longer surveillance intervals. Methods: We developed a Markov model to compare the current recommendation with colonoscopy at 3 years and subsequent colonoscopy at 5 years if no lesions or low-risk lesions are found versus a longer interval strategy based in colonoscopy at 5 years followed by subsequent colonoscopy at 10 years. We modelled a cohort of 50-year-old patients with newly diagnosed high-risk adenomas. Surveillance colonoscopies were performed until the age of 80 and patients were followed until death. Costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs) were measured. The analysis was performed using "R" software (version 2.13.1) Results: The 5 years surveillance interval supposes a saving of 158.992 colonoscopies in a 100.000 high risk-adenoma population with a cost difference of 55.329.216 €. However, this longer interval strategy results in a difference of 2.083 more colorectal cancer (CRC) cases and 562 more CRC deaths in the same population. The 3 years strategy had an average lifetime cost (ALTC) of 2,263€ whereas in the 5 years strategy this ALTC was 2,348€. The average QALYs in the 3 years surveillance arm was 21.0, and in the 5 years surveillance it was 21.7. Both strategies showed a similar cost-effectiveness rate with an ICER of 121€ per QALY favouring the 5 years strategy. The probabilistic sensitivity analysis confirmed the lack of differences between both strategies. Conclusions: A model with longer interval surveillance colonoscopies after high-risk adenoma excision shows a similar cost-effectiveness than current recommendations. This longer interval strategy would suppose a high reduction in the number of colonoscopies performed with the consequent gain in colonoscopic capacity. Studies comparing both strategies should be encouraged.
Tu1496 Missed Polyps Are Common in Patients Referred for Endoscopic Resection of Colon Polyps Rajesh N. Keswani*1, Roy M. Soetikno2, Tonya Kaltenbach2 1 Medicine, Northwestern University, Chicago, IL; 2Veteran’s Affairs Palo Alto Health Care System, Palo Alto, CA Introduction: Patients with complex colon polyps may be referred to a specialist in endoscopic resection (ER), presumably with all synchronous polyps identified or removed. The primary aim was to determine the polyp "miss" rate identified at ER. The secondary aim was to determine the association of referring physician adenoma detection rate (ADR) with polyp miss rate. Methods: Review of available data collected in two prospective colon ER databases was performed over a 4-year period (2008-2012). We included patients who had their index colonoscopy performed by a physician with a known ADR. ER of these polyps was performed by 1 of 5 physicians. We defined missed polyps as any polyps identified within one year of index colonoscopy by the ER endoscopist. We defined synchronous polyps as polyps identified (whether or not they were removed) at index colonoscopy by the referring endoscopist. Results: 96 patients (35F/61M) were referred for ER by 21 unique endoscopists. Patient median age was 65 (range 33-86). Median polyp size was 25 mm (range 10-80mm) with the majority (64.6%) of lesions classified as nonpolypoid (Paris O-IIa, IIb, or IIc). In most cases (67.7%), resection of the polyp was not attempted prior to referral. Missed polyps were identified in 67.7% of patients by the ER specialist, with 28.1% of patients harboring polyps O 10 mm in size. Synchronous polyps were identified in 71.9% of patients at index colonoscopy by the referring physician (Table). Sixty-seven patients (70.0%) were referred by physicians with an ADR below their institutional mean. There was a trend towards an increased missed polyp rate by endoscopists with low ADR as compared to those with high ADR (73.1% vs. 55.2%, pZ0.07). There was a similar trend for missed polyps O 10 mm in size and missed nonpolypoid lesions. A single missed adenocarcinoma was identified in a physician with an ADR below institutional mean. There was no difference in polyp miss rate whether synchronous polyps were seen on initial exam (69.6%) or not (63.0%). Endoscopists performing referred ER had ADR above the mean in their respective institutions. Conclusions: The majority of patients referred for ER of complex colon polyps have missed colon polyps, many of which are advanced lesions. Missed lesions appear more common when patients are referred by physicians with lower ADR. After resecting these lesions, referring and referred endoscopists should ensure that patients return for a complete surveillance examination to clear the remaining colon of neoplasia.
www.giejournal.org