M2138

Is MRI Colonography an Appropriate Alternative to Screening Colonoscopy? Mehran Anvari, Aqeel AI Aqeel, Julian Dobranowski, Catherine Gill Pottmff

I~ACKGROUND: 5~'reeinng colonoscopy is now a commoNy pertormed evaluation in patients with first degree relatives with colon cancer after the age of 40. METHODS: 21 patients (age: 47 + -2 yrs, 10F: i 1M) referred for screening colonoscopy due of history of colon cancer in at least one first degree rdative unde~'ent a MRI colonography (using a 1.5 T magnet) lust prior to their colonoscopy. Standard bowel preparation was used and patients were gwen routine sedation tbr cdonoscopy Patients were asked to score m'erall procedural diseomtort and pain on a visual analogue score of 0 (none) to 10 (unbearable). The radiologist and the three colonoscopists were blinded to the results of the other test. They were asked to report abnormalities observed and degree of confidence with the diagnosis RESULTS: In only one patient (out of six) did both colonoscopy and MRI colonography pick up the same polyp This was the largest polyp measuring 1 cm in diameter. The remaining polyps found by colonoscopy were all 5 to 8 mm and not visualized by MRL There were 3 polyps reported by" the MR1 colonography which were not picked up by colonoscopy. CONCLUSION: While MRI colonograpby is associated with less pain and discomtbrt, the correlation with colonoscopic findings was pc~r Although colonoscopy itself may be less accurate in picking smaller polyps, it should still be considered as gold standard. Use of a 3T magnet and more aggressive bowel preparation may reduce the number of ialse positives and nagatives by MRI colonography

. . . . . . . . . . . . . . . . . . . . . . ~ Mill Cotonogral)hy p value Polyps Found 6 4 Uean Size of Polyl~ 6 rnm (range 3~10) 17,5 mm (range 10~30) High Degree of Confidence 18 9 0.o4 Test Not Con~eted 2 0 Pain Score 443+-0.81 2,54*~,48 0.021 Overall Discomfort 4s 3.52~0,41 0,008 (rr~*-se)

lesion without G1M was found in 51/117 (44%), The odds ratio (OR) tbr finding GIM in patients with RL compared to no RL was 44 (95% CI: 1.8, 10.4, p<,001) The Table shows the OR for finding GIM in targeted relative to random biopsies. Conclusions: Subtle raised gastric lesions, especially PPF, are a marker of higher risk of GIM among Asian-Americans. When raised lesions are seen, targeted biopsies are more likely than random biopsies to find GIM Whether these findings can be replicated in other groups warrants further study.

Likelihood of flndhlg GIM in a raised lesion relative to "random" biopsies

Lesion OR (95% CrL)* ' p GRL 2,0 (0,95, 421) ,099 PPF 5,0 (t,28, 19,6) ,039 All Raised Lesions 3.0 (1.52, 593) ,002 *Odds ratio (95% Confidence Inter~al} of finding GIM in lesion relative to "random"

M2139

Does PPI Use Promote Colonic Neoplasia? Chnstopher Carlson, John A. Mapfli, Ellen Zimmerm_ann, D. Kim Turgeon

Proton pump inhibitors (PPIs) are one of the most utilized classes of medications in the world. PPls cause an increase in serum gastrin levels of three to four times normal. Elevated serum gastrin levds have been shovm to promote colon cancer growth in vitro and in ammaLs. In humans, some studies have shoss~a elevated serum gastrin in patients with polyps or colorectal cancer as compared to controls, but data has been conflicting. There is no clinical data for colorectal cancer screenxng recommendations in patients who are being treated with concomitant PPI therapy'. Methods: We reviewed the records of 1077 patients who had undergone a second colonoscopy for follow-up of polyps more than 1 year after the index colonoscopy between 1995 to 2001 at the University" of Michigan Medical Center. 772 patients were excluded for incomplete colonoscopy, poor prep, age < 18yrs, h/o 1BD or HNPCC/APC, or inabihty to completely remove all polyps. 328 patients had adenntnatous polyps identified and completely" removed on the initial coicmoscoDc The percentage of patients with recurrent adenomas, adenoma size (< 0.5 cm and > 0.5 cm), and adenon~ Iocanon (lefi colon, nght colon, or rectum) were recorded. Significant PPI use was established if there was documentation of use > 1 year based on medical record review. The data on PPIs users and PP1 non-users were compared Resuhs: 32% of patients had significant PPI use. Phe interval between cokmoscopies averaged 2.7 years (range 1-5). Adenomas were tound in 77/328 patients at the second cokmoscopy. A total of 133 polyps was found; 86 in PPI non-users and 47 in patients with s~gmficant PPI use. Adenomas were found in 26/ 105 (25%) PPI users and 51/223 (23%) PP1 non-users (p= 0.70). Adenoma size was > 05 cm in 22/47 (46.8%) total polyps tound in PPI users and 52/86 (60.5%) of polyps tound m non-users (p = 0~ 15). Location of adenon~s was no ditterent in either group (p = 024). Two colorectal caocers were tbund in the non-user gyoup on second colonoscopy. Conclusions: E)ur data does not support a role for PPIs in promoting colonic neoplasia. Based on our data, recommendarimls for CRC screening and surveillance intervals in these moderate risk patients do not need to be adjusted for concomitant chronic PPI use. The po~ibdity of concomitant chronic PPI use accelerating neoplastic growth in high-risk patients, such as those with HNPCC or CRC hlstor~es, requires turther evaluation

M2140

Gastric Intestinal Metaplasia in Raised Antral Lesions of Asian-Americans Thomas C. ki, Ffillel W. Coben

Gastnc intestmal metaplasia (GIM) is krmwn to be common in Pacific Rim Asian populations and is a precursor of gastric carcinoma. While GIM has been documented in Asian-Americans, its associatmn with visible pathology, has not been determmed. Methods: Pinch biopsies were obtained in 513 consecutive upper endoscopies of Asian-Americans (Chinese, Taiwanese, Japanese; aged 14-92 years, mean=46+/- l ) in a community gastroenterology practice in addition to s~weral non-targeted "random" biopsms, any raised lesions were biopsied and labeled. Results: 117 (23%) of the 513 patients were tbund to have either subtle rai~d (1- 3 ram), pol}q)oid lesions of the gastric antral mucosa, varying in width from a few millimeters to a few centimeters, or a prominent antral told that enters the pyloric channel The lesions were best visualized when the mucosa was slowly examined a centimeter or two from the surt~ace with a standard endoscope. Air aspiration and insuftlation improved detection. Raised lesions (RL) were labeled as either gastric raised lesions (GRI.) or a prominent pre-pyloric Md (PPF) GRL were seen in 101/513 (20%), PPF in 22/513 (4%), and both in 6/513 (1%) ot patients. GIM was seen in 148 of the 513 initial endoscopies (29%): in 112/513 (22%) of the "random" biopsies, in 42/101 (42%) oi GRL, and in 14/22 (e,4%) of PPF. GIM was [ound simuhaneously in raised and "random" biopsms in 26/117 (22%) GIM was seen only in raised lesions in 30/117 (26%), and only in "random" biopsies in 10/117 (8%). A raised

M2141

Development of a Novel RT-PCR Luminometric Hybridization Assay, for hTERT Active Transcript in Colorectal Cancer Tissues K Angelopoulou, Dimitris Dimitroulopoulos, A. Spiropoulou, A Stathopoulou, Klisthenis Tsamakidis, Diminios Xinopoulos, E Lianidou, Emmanuel Paraskevas

The potential of telomerase as a general diagnostic and prognostic tumor marker is evaluated since its activity is expressed in the majority" of human tumors, being absent in most healthy tissues. The aim of our study was to develop a sensitive method for the detection of those human telomerase reverse transcriptase (hTERT) mRNA transcripts that encode {'or enzy~natieally active telomerase in colorectat cancer (CRC) bioptic specimens Materials and Method: A novel n'mthodology for the determination of the tull active hTERT mRNA tran- scripts w~as performed in 30 CRC fi~rcep bioptic specimens and their corresponding adjacent and normal tissues. The determination was made using hTERT hybridiaation assay of mRNA and selective amplification of the hTERT gene with double PCR. The PCR products were captured on microriter wells via the biotin-streptavidin system and were hybridized with digoxigenin labeled probes. The hybrids were detected by' a highly sensitive Iuminometric reaction through an anti-digoxigemn antibody conjugated to alkaline phosphatase The assay" was validated with the MCF-7 breast carcinoma cell line Rasuhs: Eighteen ot 30 CRC specimens were positive for hTERT active transcript while only 3 of the corresponding adjacen~ tissues and none of the normal tissues belonging to the same patients were found positive Using different primers, amplificator of all hTERT splicing variants, 2I out of 30 CRC specimens were positive. Conclusion: The proposed luminometric hybridization assay- is highly sensitive and can be used for the determination of hTERT actwe transcript in CRC bioptic specimens.

M2142

Non-invasive Methods of Diagnosis of Gastric Intestinal Metaplasia - an observational case-control study Shaji Sebastian Pomona McLonglin, Wen@ Hall, Asgahr Qasim, Humphrey O'connor, Martin Buckley, O'morain Colm

Introduction: intestinal metaplasia is a pre-cancerous lesion in tile" muhistep carcinogenesis of gastric cancer. We investigated whether intestinal metaplasia can be detected noninvasively using the seromarkers Pepsinogen 1, Pepsmogen 11 and Gast rin- 17 Methods: 110 consecutive patients undergoing endoscopy were included. The patient group included 27 gastric ulcers, 22 duodenal ulcers and 13 gastric carcinomas. Biopsies taken from antrum, corpus and incisura were classified according to Sidney system and evaluated for the presence,extend and site of intestinal metaplasia. All patients had fasting serum Pepsmogen 1 (S-PG1), Pepsino- gen i1 (S-PGll) and Gastrin-17 (G-17) determined by EI.ISA. In addition post prandial G- 17 level was also taken alter a protein rich meal. Helicobacter pylori presence was identified

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