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Colon Polyp Recurrence: Predictors of Early Development of Significant Polyp
*W1667 Can Magnification Chromo-Colonoscopy Predict the Histology of Colorectal Polyps More Accurately Than Conventional Colonoscopy? Kazutomo Togashi, Graham L. Radaford-Smith, David G. Hewett, David A. Whitaker, Georgia E. Hume, Leo Francis, Mark N. Appleyard Background: There are few data on the accuracy of magnifying colonoscopy compared with conventional high resolution colonoscopy in histological prediction of polyps in a western population. Methods: 203 patients prospectively entered the study. All examinations were performed by one experienced colonoscopist using high resolution magnifying colonoscopes. Upon detection of a lesion, a prediction of the histology (neoplastic vs. non-neoplastic) was made: (1) before indigocarmine (IC) spray, (2) after IC spray and (3) after magnification in real time. All detected lesions including apparently hyperplastic polyps were evaluated and resected using standard endoscopic techniques. Results: A total of 524 lesions including 283 neoplastic and 241 non-neoplastic lesions were evaluated. Accuracy of histological prediction was (1) 81% before IC spray, (2) 86% after IC, and (3) 92% after magnification. There were significant differences in accuracy before and after IC (p=0.036), and with magnification after IC (p=0.002). After magnification, the accuracy of neoplastic lesions was 90%, and that of non-neoplastic lesions was 94%. There were 27 neoplastic lesions which were incorrectly identified as non-neoplastic lesions. These 27 incorrectly identified neoplastic lesions were comprised of 20 tubular adenomas with mild dysplasia, 2 mixed lesions and 5 serrated adenomas. All 5 serrated adenomas were greater than 10 mm in size. The main reasons for incorrect identification of the 20 tubular adenomas and 2 mixed lesions were: an unclear image in 17 and a difficult pit pattern in 3 cases. Conclusion: Magnifying chromo-colonoscopy was more accurate than conventional colonoscopy for predicting the histology of colorectal polyps. High prediction rates using conventional colonoscopy might be attributable to the expertise of the particular colonoscopist and may not be universally applicable. Therefore, the magnitude of the difference in accuracy between conventional and magnifying colonoscopy may increase with less experienced colonoscopists.
*W1668 Colon Polyp Recurrence: Predictors of Early Development of Significant Polyp Jin-Bae Kim, Dong-Soo Han, Jong-Pyo Kim, Hang-Lak Lee, JooHyun Sohn, Joon-Soo Hahm Background/Aims: It has been reported that the recurrence rate of colon polyp after polypectomy is around 39% in 3 years. It, however, is recommended that 3 year is optimal follow up period after polypectomy in the meaning of significant polyp (size $1cm or dysplasia) recurrence. Initial polyp number, presence of significant polyp, and age factor are considered as a risk factor for recurrence of polyp after polypectomy. We retrospectively determined the cumulative recurrence rate of neoplastic polyps and significant polyps in patients who underwent polypectomy. Methods: Ninety-seven patients underwent total colonoscopy 5-81 months after initial endoscopic polypectomy. All polyps were endoscopically removed by methods of biopsy forcep removal/snare polypectomy and an adenoma was considered as significant if the diameter was $1cm and/or villous component and/or severe dysplasia were present. Results: (1) Mean age of patient who underwent polypectomy was 57 and 70% was male. Mean colonoscopic follow-up period was 25 months. Mean number of initial polyp was 2.2 (range, 1-11) and significant polyps were observed in 43%. (2) Cumulative recurrence rate of colon polyp was 13.8% in 1 year, and 60% in 3 year, which is compared to the finding that cumulative recurrence rate of significant polyps was 2.5% and 31%, respectively. Kaplan-Meier projections estimate that 50% will have a significant polyp recurrent polyp within 56 months (95% CI, 34-78 months). (3) There was no difference in overall cumulative polyp and significant polyp recurrence according to the methods of polyp removal, presence of initial significant polyp, initial location of colon polyp. However, significant difference in overall cumulative polyp and significant polyp recurrence was noted according to the initial polyp number (p<0.05). The age at the diagnosis of colon polyp was significant only in overall polyp recurrent rate (p=0.01). (4) In cox-regression analysis, apart from initial polyp number, no other parameters contributed to significant polyp recurrence. Patients who initially had one polyp showed 15% of significant polyp recurrence within 3 years regardless of age. Conclusion: Significant polyp recurrence is very rare within one year after polypectomy. Patients with single polyp are identified low risk group and their surveillance examination may be delayed beyond the standard 3 years. When performing surveillance colonoscopy in patient s with 2 or more polyps, initial polyp number and age should be considered.
VOLUME 59, NO. 5, 2004
*W1669 Endoscopic Diagnosis of Laterally Spreading Tumors in the Colorectum—A Treatment Consideration— Toshio Uraoka, Yutaka Saito, Takahisa Matsuda, Akira Emura, Nozomu Kobayashi, Daizo Saito, Takahiro Fujii Although laterally spreading tumors (LSTs) are best removed by EMR, accurate diagnosis of the submucosal (sm) invasion is clinically important. The aim of this study was to determine the endoscopic findings in a large number of LSTs with sm invasion and clarify the indications for EMR. A total of 445 colorectal LSTs resected endoscopic or surgically were evaluated retrospectively. There were 242 granular types (LST-Gs), 230 adenomas or intramucosal adenocarcinomas and 12 submucosal adenocarcinomas (sm-Ca) and 203 non-granular types (LST-NGs), 183 adenomas or intramucosal adenocarcinomas and 20 sm-Ca. Eight endoscopic findings were investigated by univariate or multivariate analysis for their possible association with sm invasion: 1. Size of tumor ($20mm), 2. Redness, 3. Large nodule ($10mm), 4. Depressed area, 5. Sclerous change of the wall, 6. Fold convergency, 7. Chicken skin mucosa, and 8. Pit pattern (Invasive pattern). We investigated the relation between significant endoscopic findings and the area of sm invasion. In both LST-Gs and LST-NGs, depressed area, large nodule, pit pattern and redness were significantly associated with an increased risk of sm invasion according to univariate analysis. Additionally, in LST-NGs, size and fold convergency were also significant. Furthermore in LST-Gs, large nodule was an independent risk factor for sm invasion (p=0.0001). Accuracy, sensitivity and specificity were 29 %, 83 % and 90 % respectively. In LST-NGs, Invasive pattern and size were independent risk factors for sm invasion (p<0.0001, p=0.04). Accuracy, sensitivity and specificity were 85 %, 55 % and 99 % respectively. In 90% of sm LST-Gs, penetration was found under the large nodule. On the other hand, in 45 % of LST-NGs without Invasive pattern the area of sm penetration was difficult to diagnose. Considering these data, we recommend that in LST-Gs the area including the large nodule should be resected at first. In contrast, LSTNGs should be removed en bloc for accurate histopathological diagnosis.
*W1670 Importance of Hyperplastic Polyps and Adenomas 5mm or Less in Diameter That Are Detected by Screening Flexible Sigmoidoscopy James Park, Fritz Francois, Edmund J. Bini Background: The need for full colonoscopy in patients with hyperplastic polyps or adenomas 5mm or less in diameter that are detected by screening flexible sigmoidoscopy (FS) is controversial. The aim of this study was to determine the prevalence of proximal colonic neoplasms in a large cohort of patients with distal polyps detected by screening FS. Methods: Consecutive asymptomatic patients at average-risk for colorectal cancer who were referred for screening FS were prospectively enrolled from 1/98 through 10/03. A detailed medical history was obtained from all patients prior to FS, and colonoscopy was offered to all subjects with polyps on FS. Polyps detected by FS were classified as hyperplastic, diminutive adenomas (# 5mm in diameter), small adenomas (6 - 9 mm in diameter), large adenomas ($ 10mm in diameter), or cancers. In patients with more than one polyp, classification was based on the most advanced lesion. For each type of lesion on FS, we determined the proportion of patients who had any adenomas, advanced colonic neoplasms, or cancers detected by colonoscopy in the proximal colon. Advanced colonic neoplasms were defined as adenomas $ 10mm in diameter or any adenoma, regardless of size, with villous histology, high-grade dysplasia, or cancer. Results: A total of 2,084 patients (mean age 66.5 6 9.4 years) were enrolled, and the mean depth of insertion of the sigmoidoscope was 57.7 6 7.1 cm. One or more polyps were detected in 491 of the 2,084 patients (23.6%), and the most advanced lesion on FS was classified as a hyperplastic polyp in 8.4% of patients, adenoma # 5mm in 6.4%, adenoma 6 - 9 mm in 3.2%, adenoma $ 10mm in 3.2%, and cancer in 0.5% of subjects. Of the 491 patients with a polyp on FS, 482 of these subjects (98.2%) underwent colonoscopy and 97.5% of these examinations were complete to the cecum. Conclusions: There was a substantial prevalence of proximal adenomas and advanced colonic neoplasms in asymptomatic averagerisk patients with distal hyperplastic polyps and adenomas # 5mm in diameter. Colonoscopy should be offered to individuals found to have hyperplastic or diminutive adenomas on FS.
GASTROINTESTINAL ENDOSCOPY
P283
*W1668 Colon Polyp Recurrence: Predictors of Early Development of Significant Polyp Jin-Bae Kim, Dong-Soo Han, Jong-Pyo Kim, Hang-Lak Lee, JooHyun Sohn, Joon-Soo Hahm Background/Aims: It has been reported that the recurrence rate of colon polyp after polypectomy is around 39% in 3 years. It, however, is recommended that 3 year is optimal follow up period after polypectomy in the meaning of significant polyp (size $1cm or dysplasia) recurrence. Initial polyp number, presence of significant polyp, and age factor are considered as a risk factor for recurrence of polyp after polypectomy. We retrospectively determined the cumulative recurrence rate of neoplastic polyps and significant polyps in patients who underwent polypectomy. Methods: Ninety-seven patients underwent total colonoscopy 5-81 months after initial endoscopic polypectomy. All polyps were endoscopically removed by methods of biopsy forcep removal/snare polypectomy and an adenoma was considered as significant if the diameter was $1cm and/or villous component and/or severe dysplasia were present. Results: (1) Mean age of patient who underwent polypectomy was 57 and 70% was male. Mean colonoscopic follow-up period was 25 months. Mean number of initial polyp was 2.2 (range, 1-11) and significant polyps were observed in 43%. (2) Cumulative recurrence rate of colon polyp was 13.8% in 1 year, and 60% in 3 year, which is compared to the finding that cumulative recurrence rate of significant polyps was 2.5% and 31%, respectively. Kaplan-Meier projections estimate that 50% will have a significant polyp recurrent polyp within 56 months (95% CI, 34-78 months). (3) There was no difference in overall cumulative polyp and significant polyp recurrence according to the methods of polyp removal, presence of initial significant polyp, initial location of colon polyp. However, significant difference in overall cumulative polyp and significant polyp recurrence was noted according to the initial polyp number (p<0.05). The age at the diagnosis of colon polyp was significant only in overall polyp recurrent rate (p=0.01). (4) In cox-regression analysis, apart from initial polyp number, no other parameters contributed to significant polyp recurrence. Patients who initially had one polyp showed 15% of significant polyp recurrence within 3 years regardless of age. Conclusion: Significant polyp recurrence is very rare within one year after polypectomy. Patients with single polyp are identified low risk group and their surveillance examination may be delayed beyond the standard 3 years. When performing surveillance colonoscopy in patient s with 2 or more polyps, initial polyp number and age should be considered.
VOLUME 59, NO. 5, 2004
*W1669 Endoscopic Diagnosis of Laterally Spreading Tumors in the Colorectum—A Treatment Consideration— Toshio Uraoka, Yutaka Saito, Takahisa Matsuda, Akira Emura, Nozomu Kobayashi, Daizo Saito, Takahiro Fujii Although laterally spreading tumors (LSTs) are best removed by EMR, accurate diagnosis of the submucosal (sm) invasion is clinically important. The aim of this study was to determine the endoscopic findings in a large number of LSTs with sm invasion and clarify the indications for EMR. A total of 445 colorectal LSTs resected endoscopic or surgically were evaluated retrospectively. There were 242 granular types (LST-Gs), 230 adenomas or intramucosal adenocarcinomas and 12 submucosal adenocarcinomas (sm-Ca) and 203 non-granular types (LST-NGs), 183 adenomas or intramucosal adenocarcinomas and 20 sm-Ca. Eight endoscopic findings were investigated by univariate or multivariate analysis for their possible association with sm invasion: 1. Size of tumor ($20mm), 2. Redness, 3. Large nodule ($10mm), 4. Depressed area, 5. Sclerous change of the wall, 6. Fold convergency, 7. Chicken skin mucosa, and 8. Pit pattern (Invasive pattern). We investigated the relation between significant endoscopic findings and the area of sm invasion. In both LST-Gs and LST-NGs, depressed area, large nodule, pit pattern and redness were significantly associated with an increased risk of sm invasion according to univariate analysis. Additionally, in LST-NGs, size and fold convergency were also significant. Furthermore in LST-Gs, large nodule was an independent risk factor for sm invasion (p=0.0001). Accuracy, sensitivity and specificity were 29 %, 83 % and 90 % respectively. In LST-NGs, Invasive pattern and size were independent risk factors for sm invasion (p<0.0001, p=0.04). Accuracy, sensitivity and specificity were 85 %, 55 % and 99 % respectively. In 90% of sm LST-Gs, penetration was found under the large nodule. On the other hand, in 45 % of LST-NGs without Invasive pattern the area of sm penetration was difficult to diagnose. Considering these data, we recommend that in LST-Gs the area including the large nodule should be resected at first. In contrast, LSTNGs should be removed en bloc for accurate histopathological diagnosis.
*W1670 Importance of Hyperplastic Polyps and Adenomas 5mm or Less in Diameter That Are Detected by Screening Flexible Sigmoidoscopy James Park, Fritz Francois, Edmund J. Bini Background: The need for full colonoscopy in patients with hyperplastic polyps or adenomas 5mm or less in diameter that are detected by screening flexible sigmoidoscopy (FS) is controversial. The aim of this study was to determine the prevalence of proximal colonic neoplasms in a large cohort of patients with distal polyps detected by screening FS. Methods: Consecutive asymptomatic patients at average-risk for colorectal cancer who were referred for screening FS were prospectively enrolled from 1/98 through 10/03. A detailed medical history was obtained from all patients prior to FS, and colonoscopy was offered to all subjects with polyps on FS. Polyps detected by FS were classified as hyperplastic, diminutive adenomas (# 5mm in diameter), small adenomas (6 - 9 mm in diameter), large adenomas ($ 10mm in diameter), or cancers. In patients with more than one polyp, classification was based on the most advanced lesion. For each type of lesion on FS, we determined the proportion of patients who had any adenomas, advanced colonic neoplasms, or cancers detected by colonoscopy in the proximal colon. Advanced colonic neoplasms were defined as adenomas $ 10mm in diameter or any adenoma, regardless of size, with villous histology, high-grade dysplasia, or cancer. Results: A total of 2,084 patients (mean age 66.5 6 9.4 years) were enrolled, and the mean depth of insertion of the sigmoidoscope was 57.7 6 7.1 cm. One or more polyps were detected in 491 of the 2,084 patients (23.6%), and the most advanced lesion on FS was classified as a hyperplastic polyp in 8.4% of patients, adenoma # 5mm in 6.4%, adenoma 6 - 9 mm in 3.2%, adenoma $ 10mm in 3.2%, and cancer in 0.5% of subjects. Of the 491 patients with a polyp on FS, 482 of these subjects (98.2%) underwent colonoscopy and 97.5% of these examinations were complete to the cecum. Conclusions: There was a substantial prevalence of proximal adenomas and advanced colonic neoplasms in asymptomatic averagerisk patients with distal hyperplastic polyps and adenomas # 5mm in diameter. Colonoscopy should be offered to individuals found to have hyperplastic or diminutive adenomas on FS.
GASTROINTESTINAL ENDOSCOPY
P283