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⁎4497 Cyclooxygenase-2 expression in colorectal polyp.
*4496 FOLLOW-UP AND LASER ND-YAG TREATMENT OF ADENOMAS IN THE RECTAL STUMP OF FAMILIAL ADENOMATOUS POLYPOSIS (FAP) PATIENTS: LONG TERM RESULTS. Rita Slim, Thierry Ponchon, Annick Chavaillon, Francoise Desseigne, Adelino Perreira, Jean-Christophe Saurin, E Herriot Hosp, Lyon, France. Aim and Background : The risk of rectal cancer development in the rectal stump of FAP patients with ileorectal anastomosis is well known, but the impact of endoscopic follow-up, and coagulation of residual polyps, on this cancer risk remains unclear. We evaluated retrospectively the results of follow-up with Nd-YAG laser destruction of adenomas in the rectal stump of these patients. Methods: We included all patients with classical FAP and ileo-rectal anastomosis followed at our institution between 1975 and 1999. There were 24 patients (12 females, 12 males, mean age 41 years, range 2260), with a median delay of 3 years (range 0-23 years) between colectomy and the beginning of the follow-up. Rectoscopy was performed under general anesthesia, with systematic indigo-carmine dye. After histologic confirmation of their adenomatous nature, the majority of visible polyps were treated using Nd-YAG laser with a power of 25 Watts. Biopsies were obtained at each endoscopy from the largest polyps. The number of rectal polyps was evaluated from endoscopic reports and classified in 3 categories: more than 50, 10-50, less than 10 polyps. Results: The 24 patients had 158 laser sessions with a mean of 6/patient (range 1-17), during a median follow-up of 8 years (range 1-18). Three complications (1 hemorrhage, 2 retroperitoneal perforations) were treated medically. The number of rectal polyps at initial endoscopy were: > 50, 12 patients; 10-50, 10 patients; < 10: 2 patients. Polyp’s number regressed in 16 (66.6 %) cases (7 with > 50 polyps initially, 9 with 10-50 polyps initially), and remained stable in 4 (16.6 %) patients (2 with > 50 polyps and a follow-up of 9 and 11 years, 2 with < 10 polyps initially). At last endoscopy, 14 (58.3 %) patients had less than 10 polyps in the rectal stump. Four patients (16.6 %) necessitated a proctectomy, in all cases because of uncontrolled increase of polyp’s number and size. Two patients had adenomas with severe dysplasia at initial endoscopy and were successfully treated with < 10 residual polyps (follow-up 3 and 4 years. No patient developed severe dysplasia or cancer during the follow-up, including the 4 cases who were treated surgically. Conclusion: Using regular endoscopic follow-up and laser Nd-YAG treatment, adenomas in the rectal stump can be controlled in the large majority of patients with FAP and ileo-rectal anastomosis, with no development of severe dysplasia or cancer during long-term follow-up.
*4498 MALIGNANT POTENTIAL OF COLORECTAL FLAT ADENOMA. Won Ho Kim, Jung Hoon Suh, Young Hoon Youn, Yong Han Paik, Yong Suk Cho, Ho Geun Kim, Nam Kyu Kim, Jin Kyung Kang, Yonsei Univ Coll of Medicine, Seoul, South Korea. Background: Colorectal flat adenoma, meaning that their growth above the muscularis mucosa is no more than two times the thickness of the normal mucosa or height is less than 1/2 or 1/4 of longest diameter of adenoma, has been the focus of attention because of its higher malignant potential compared to polypoid adenoma. Aim: We wanted to evaluate the clinicopathological characteristics of flat adenomas and to analyze the factors associated with malignant transformation of colorectal flat adenomas. Subjects and Methods: From Jan. 1991 to Jul. 1999, 115 flat adenomas larger than 5 mm were diagnosed in 87 patients (63 male and 24 female) by colonoscopy. Adenomas equal or smaller than 5 mm was excluded because of difficulty in differentiation of flat and sessile lesions. Of those, 24 and 5 patients had a history of colorectal polyp and cancer, respectively. Mean age of the patients was 61 years (range: 36-79). Half of the patients had synchronous adenoma and 12% had a synchronous carcinoma of the colorectum. Results: The rectum (32%) was the most common site of flat adenoma, followed by sigmoid (19%), transverse (18%) and ascending colon (15%). Half of the flat adenomas were small (6-10 mm), 28% were 11-20 mm and remainder (23%) were larger than 20 mm. The surface was smooth in 56%, granular in 20% and nodular in 24%. Histologically, 70%, 21% and 5% of flat adenomas were tubular, tubulovillous, and villous adenoma, respectively. Five lesions were composed of carcinoma without any adenomatous tissue. High-grade dysplasia, intramucosal carcinoma and invasive carcinoma were diagnosed in 10%, 8% and 6% of flat adenomas, respectively. Univariate analysis demonstrated that distal location, larger size, nodular surface pattern, and villous histologic type of flat adenomas were factors associated with malignant transformation in terms of intramucosal carcinoma or invasive carcinoma. However, the size of flat adenomas was revealed as the only significant risk factor for malignancy in multivariate analysis. Conclusion: Flat adenoma of colorectum is a real disease entity and it has a relatively high malignant potential. Therefore, colonoscopic recognition of flat adenoma may play an important role for primary and secondary prevention of colorectal carcinoma.
*4497 CYCLOOXYGENASE-2 EXPRESSION IN COLORECTAL POLYP. Goo Lee, Hoon jai Chun, Donghoon Kim, Changwoo Lee, Yoontae Jeen, Hongsik Lee, Chiwook Song, Soonho Um, Changduck Kim, Hosang Ryu, Jinhai Hyun, Hankyum Kim, Dept of internal medicine, Dongguk Univ , Coll of Medicine, Pohang, South Korea; Dept of internal medicine, Korea Univ , Coll of medicine, Seoul, South Korea; Dept of Pathology, Dongguk Univ , Coll of Medicine, Pohang, South Korea; Dept of Pathology, Korea Univ , Coll of medicine, Seoul, South Korea. Backgrounds/Aim:Recent studies have shown that cyclooxygenase(COX)-2 involves in the tumorigenesis in colorectal neoplasia. However, the timing of COX-2 expression during adenoma-carcinoma sequence is not completely established. The aim of this study was to evaluate COX-2 expression in colorectal polyp according to histologic type. Materials and Methods:52 patients with colorectal polyp from endoscopic polypectomy or surgical resection were enrolled. Polyps were divided histologically as follows;12 hyperplastic polyps(HP), 13 adenomas with low grade dysplasia(LGD), 12 adenomas with high grade dysplasia(HGD) and 15 malignant polyps(MP, carcinoma arising from adenoma). They were stained for COX-2 by avidinbiotin immunohistochemical technique using polyclonal IgG antibody. The intensity and extent of staining were semi-quantitatively accessed by two pathologists, blinded to outcome. Results:COX-2 was stained in varying intensity in tumor cells of 7 per 12 HGDs and 11 per 15 MPs, though was not in those of all LGDs and HPs. Percentage of COX-2 expression in tumor epithelial cells was 20 to 40% in 6 HGDs and above 50% in 10 MPs. Strong COX-2 staining was also observed in stromal components such as mononuclear cells, endothelial cells of all adenomas and carcinomas. Conclusion: The frequency and intensity of COX-2 expression was increased in both adenoma with high grade dysplasia and carcinoma. These results suggest that up-regulation of COX-2 has an important role in tumor progression from the late stage of colorectal adenoma.
*4499 EFFECT OF VARIABLE STIFFNESS COLONOSCOPES ON CECAL INTUBATION TIMES FOR ROUTINE COLONOSCOPY IN SEDATED PATIENTS. Douglas K. Rex, B. A. Flamme, D. Heilman, Indiana Univ Med Ctr, Indianapolis, IN. Background: Variable stiffness (VS) colonoscopes allow passage of the rectosigmoid in a flexible mode followed by stiffening to prevent looping. In this study cecal intubation time was compared with 4 Olympus colonoscopes: standard adult CF-140(SA), standard pediatric PCF-140 (SP), VS adult (VSA) and VS pediatric (VSP). Method: All exams were performed by a single experienced examiner. 110 were excluded for the following reasons: colon resection (N=42), pediatric scope selected for stricture, known severe diverticulosis, etc. (n=24), IBD (n=32), failed colonoscopy at another facility (n=6) acute GI bleed (n=6). For 355 remaining consecutive sedated examinations, scopes were rotated with scopes left out of rotation if they were not yet sterile or needed repair. All patients were sedated independently by nurses. Results: 99.2% of exams were complete to the cecum. The stiffness device was activated in 61% of VSA and 80% of VSP exams. The number of exams with each scope was SA n=125, SP n=92, VSP n=75, VSA n=63. There was no difference between scope groups in percent male (55%), mean age (55 years), or percent of women with prior hysterectomy (44%). The examiner judged the device very useful, somewhat useful and no help in 46%, 44% and 10% of VSA exams and 55%, 33% and 12% of VSP exams Mean cecal intubation time in minutes for SA was 4.09, SP 4.05, VSP 4.04, VSA 3.93 (P=0.98). The percent of intubations in < 2 min was 15.4%, 2-3 min 25.9%, 3-4 min 19.1%, 4-5 min 16.0%,> 5 min 23.7% with no difference between scopes. Nurses assessment of pain was not different between scopes (p=0.8). Use of abdominal pressure was numerically lower with VS scopes (44% vs. 53%), but not significant (p=0.4). Conclusion: VS scopes were frequently judged useful by an experienced examiner but did not impact cecal intubation times. Additional studies by other experienced and inexperienced examiners as well as evaluation of additional technical improvements and evaluation in unsedated patients are needed.
VOLUME 51, NO. 4, PART 2, 2000
GASTROINTESTINAL ENDOSCOPY
AB151
*4498 MALIGNANT POTENTIAL OF COLORECTAL FLAT ADENOMA. Won Ho Kim, Jung Hoon Suh, Young Hoon Youn, Yong Han Paik, Yong Suk Cho, Ho Geun Kim, Nam Kyu Kim, Jin Kyung Kang, Yonsei Univ Coll of Medicine, Seoul, South Korea. Background: Colorectal flat adenoma, meaning that their growth above the muscularis mucosa is no more than two times the thickness of the normal mucosa or height is less than 1/2 or 1/4 of longest diameter of adenoma, has been the focus of attention because of its higher malignant potential compared to polypoid adenoma. Aim: We wanted to evaluate the clinicopathological characteristics of flat adenomas and to analyze the factors associated with malignant transformation of colorectal flat adenomas. Subjects and Methods: From Jan. 1991 to Jul. 1999, 115 flat adenomas larger than 5 mm were diagnosed in 87 patients (63 male and 24 female) by colonoscopy. Adenomas equal or smaller than 5 mm was excluded because of difficulty in differentiation of flat and sessile lesions. Of those, 24 and 5 patients had a history of colorectal polyp and cancer, respectively. Mean age of the patients was 61 years (range: 36-79). Half of the patients had synchronous adenoma and 12% had a synchronous carcinoma of the colorectum. Results: The rectum (32%) was the most common site of flat adenoma, followed by sigmoid (19%), transverse (18%) and ascending colon (15%). Half of the flat adenomas were small (6-10 mm), 28% were 11-20 mm and remainder (23%) were larger than 20 mm. The surface was smooth in 56%, granular in 20% and nodular in 24%. Histologically, 70%, 21% and 5% of flat adenomas were tubular, tubulovillous, and villous adenoma, respectively. Five lesions were composed of carcinoma without any adenomatous tissue. High-grade dysplasia, intramucosal carcinoma and invasive carcinoma were diagnosed in 10%, 8% and 6% of flat adenomas, respectively. Univariate analysis demonstrated that distal location, larger size, nodular surface pattern, and villous histologic type of flat adenomas were factors associated with malignant transformation in terms of intramucosal carcinoma or invasive carcinoma. However, the size of flat adenomas was revealed as the only significant risk factor for malignancy in multivariate analysis. Conclusion: Flat adenoma of colorectum is a real disease entity and it has a relatively high malignant potential. Therefore, colonoscopic recognition of flat adenoma may play an important role for primary and secondary prevention of colorectal carcinoma.
*4497 CYCLOOXYGENASE-2 EXPRESSION IN COLORECTAL POLYP. Goo Lee, Hoon jai Chun, Donghoon Kim, Changwoo Lee, Yoontae Jeen, Hongsik Lee, Chiwook Song, Soonho Um, Changduck Kim, Hosang Ryu, Jinhai Hyun, Hankyum Kim, Dept of internal medicine, Dongguk Univ , Coll of Medicine, Pohang, South Korea; Dept of internal medicine, Korea Univ , Coll of medicine, Seoul, South Korea; Dept of Pathology, Dongguk Univ , Coll of Medicine, Pohang, South Korea; Dept of Pathology, Korea Univ , Coll of medicine, Seoul, South Korea. Backgrounds/Aim:Recent studies have shown that cyclooxygenase(COX)-2 involves in the tumorigenesis in colorectal neoplasia. However, the timing of COX-2 expression during adenoma-carcinoma sequence is not completely established. The aim of this study was to evaluate COX-2 expression in colorectal polyp according to histologic type. Materials and Methods:52 patients with colorectal polyp from endoscopic polypectomy or surgical resection were enrolled. Polyps were divided histologically as follows;12 hyperplastic polyps(HP), 13 adenomas with low grade dysplasia(LGD), 12 adenomas with high grade dysplasia(HGD) and 15 malignant polyps(MP, carcinoma arising from adenoma). They were stained for COX-2 by avidinbiotin immunohistochemical technique using polyclonal IgG antibody. The intensity and extent of staining were semi-quantitatively accessed by two pathologists, blinded to outcome. Results:COX-2 was stained in varying intensity in tumor cells of 7 per 12 HGDs and 11 per 15 MPs, though was not in those of all LGDs and HPs. Percentage of COX-2 expression in tumor epithelial cells was 20 to 40% in 6 HGDs and above 50% in 10 MPs. Strong COX-2 staining was also observed in stromal components such as mononuclear cells, endothelial cells of all adenomas and carcinomas. Conclusion: The frequency and intensity of COX-2 expression was increased in both adenoma with high grade dysplasia and carcinoma. These results suggest that up-regulation of COX-2 has an important role in tumor progression from the late stage of colorectal adenoma.
*4499 EFFECT OF VARIABLE STIFFNESS COLONOSCOPES ON CECAL INTUBATION TIMES FOR ROUTINE COLONOSCOPY IN SEDATED PATIENTS. Douglas K. Rex, B. A. Flamme, D. Heilman, Indiana Univ Med Ctr, Indianapolis, IN. Background: Variable stiffness (VS) colonoscopes allow passage of the rectosigmoid in a flexible mode followed by stiffening to prevent looping. In this study cecal intubation time was compared with 4 Olympus colonoscopes: standard adult CF-140(SA), standard pediatric PCF-140 (SP), VS adult (VSA) and VS pediatric (VSP). Method: All exams were performed by a single experienced examiner. 110 were excluded for the following reasons: colon resection (N=42), pediatric scope selected for stricture, known severe diverticulosis, etc. (n=24), IBD (n=32), failed colonoscopy at another facility (n=6) acute GI bleed (n=6). For 355 remaining consecutive sedated examinations, scopes were rotated with scopes left out of rotation if they were not yet sterile or needed repair. All patients were sedated independently by nurses. Results: 99.2% of exams were complete to the cecum. The stiffness device was activated in 61% of VSA and 80% of VSP exams. The number of exams with each scope was SA n=125, SP n=92, VSP n=75, VSA n=63. There was no difference between scope groups in percent male (55%), mean age (55 years), or percent of women with prior hysterectomy (44%). The examiner judged the device very useful, somewhat useful and no help in 46%, 44% and 10% of VSA exams and 55%, 33% and 12% of VSP exams Mean cecal intubation time in minutes for SA was 4.09, SP 4.05, VSP 4.04, VSA 3.93 (P=0.98). The percent of intubations in < 2 min was 15.4%, 2-3 min 25.9%, 3-4 min 19.1%, 4-5 min 16.0%,> 5 min 23.7% with no difference between scopes. Nurses assessment of pain was not different between scopes (p=0.8). Use of abdominal pressure was numerically lower with VS scopes (44% vs. 53%), but not significant (p=0.4). Conclusion: VS scopes were frequently judged useful by an experienced examiner but did not impact cecal intubation times. Additional studies by other experienced and inexperienced examiners as well as evaluation of additional technical improvements and evaluation in unsedated patients are needed.
VOLUME 51, NO. 4, PART 2, 2000
GASTROINTESTINAL ENDOSCOPY
AB151