Colonoscopic yield of colorectal neoplasia in daily clinical practice

AIM:To assess the prevalence and location of ad-vanced neoplasia in patients undergoing colonoscopy,and to compare the yield per indication.METHODS:In a multicenter colonoscopy survey (n = 18 hospitals) in the Amsterdam area (Northern Holland),data of all colonoscopies performed during a three month period in 2005 were analyzed. The location and the histological features of all colonic neoplasia were recorded. The prevalence and the distribution ofadvanced colorectal neoplasia and differences in yield between indication clusters were evaluated. Advanced neoplasm was defi ned as adenoma > 10 mm in size,with > 25% villous features or with high-grade dyspla-sia or cancer.RESULTS:A total of 4623 eligible patients underwent a total colonoscopy. The prevalence of advanced neo-plasia was 13%,with 281 (6%) adenocarcinomas and 342 (7%) advanced adenomas. Sixty-seven percent and 33% of advanced neoplasia were located in the distal and proximal colon,respectively. Of all patients with right-sided advanced neoplasia (n = 228),51% had a normal distal colon,whereas 27% had a syn-chronous distal adenoma. Ten percent of all colono-scopies were performed in asymptomatic patients,7% of whom had advanced neoplasia. In the respective procedure indication clusters,the prevalence of right-sided advanced neoplasia ranged from 11%-57%. CONCLUSION:One out of every 7-8 colonoscopies yielded an advanced colorectal neoplasm. Colonoscopy is warranted for the evaluation of both symptomatic and asymptomatic patients.

Retrospective analysis of old-age colitis in the Dutch inflammatory bowel disease population

AIM： To describe the characteristics of Dutch patients with chronic.inflammatory bowel disease （IBD） first diagnosed above 60 years of age-a disease also known as old-age colitis （OAC） and to highlight a condition that has a similar appearance to IBD, namely segmen- tal colitis associated with diverticular disease （SCAD）. METHODS： A retrospective longitudinal survey of patient demographic and clinical characteristics, disease characteristics, diagnostic methods, management and course of disease was performed. The median follow-up period was 10 years. RESULTS： Of a total of 1100 IBD patients attending the Department of Gastroenterology, 59 （50） [median age 82 years （range 64-101）; 25 male （42%）] were identified. These patients were diagnosed with ulcerative colitis （n = 37, 61%）, Crohn＇s disease （n = 14, 24%）, and indeterminate colitis （n = 8, 15%）. Remission was induced in 40 （68%） patients within a median interval of 6 mo （range 1-21） and immunosuppressive therapy was well tolerated. Histological evaluation based on many biopsy samples and the course of the disease led to other diagnosis, namely SCAD instead of IBD in five （8%） patients. CONCLUSION： OAC is not an infrequent problem for the gastroenterologist, and should be considered in the evaluation of older patients with clinical features suggestive of IBD. Extra awareness and extensive biopsy sampling are required in order to avoid an erroneous diagnosis purely based on histological mimicry of changes seen in SCAD, when diagnosing IBD in the presence of diverticulosis coli.

Missed colorectal cancers in a fecal immunochemical test-based screening program: Molecular profiling of interval carcinomas

BACKGROUND For optimizing fecal immunochemical test(FIT)-based screening programs,reducing the rate of missed colorectal cancers(CRCs)by FIT(FIT-interval CRCs)is an important aspect.Knowledge of the molecular make-up of these missed lesions could facilitate more accurate detection of all(precursor)lesions.AIM To compare the molecular make-up of FIT-interval CRCs to lesions that are detected by FIT[screen-detected CRCs(SD-CRCs)].METHODS FIT-interval CRCs observed in a Dutch pilot-program of FIT-based screening were compared to a control group of SD-CRCs in a 1:2 ratio,resulting in 27 FIT-interval CRC and 54 SD-CRCs.Molecular analyses included microsatellite instability(MSI),CpG island methylator phenotype(CIMP),DNA sequence mutations and copy number alterations(CNAs).RESULTS Although no significant differences were reached,FIT-interval CRCs were more often CIMP positive and MSI positive(33%CIMP in FIT-interval CRCs vs 21%in SD-CRCs(P=0.274);19%MSI in FIT-interval CRCs vs 12%in SD-CRCs(P=0.469)),and showed more often serrated pathway associated features such as BRAF(30%vs 12%,P=0.090)and PTEN(15%vs 2.4%,P=0.063)mutations.APC mutations,a classic feature of the adenoma-carcinoma-sequence,were more abundant in SD-CRCs(68%vs 40%in FIT-interval CRCs P=0.035).Regarding CNAs differences between the two groups;FIT-interval CRCs less often showed gains at the regions 8p11.22-q24.3(P=0.009),and more often gains at 20p13-p12.1(P=0.039).CONCLUSION Serrated pathway associated molecular features seem to be more common in FIT-interval CRCs,while classic adenoma carcinoma pathway associated molecular features seem to be more common in SD-CRCs.This indicates that proximal serrated lesions may be overrepresented among FITinterval CRCs.

Similar fecal immunochemical test results in screening and referral colorectal cancer

AIM: To improve the interpretation of fecal immunochemical test (FIT) results in colorectal cancer (CRC) cases from screening and referral cohorts. METHODS: In this comparative observational study, two prospective cohorts of CRC cases were compared. The first cohort was obtained from 10 322 average risk subjects invited for CRC screening with FIT, of which, only subjects with a positive FIT were referred for colonoscopy. The second cohort was obtained from 3637 subjects scheduled for elective colonoscopy with a positive FIT result. The same FIT and positivity threshold (OC sensor; ≥ 50 ng/mL) was used in both cohorts. Colonoscopy was performed in all referral subjects and in FIT positive screening subjects. All CRC cases were selected from both cohorts. Outcome measurements were mean FIT results and FIT scores per tissue tumor stage (T stage). RESULTS: One hundred and eighteen patients with CRC were included in the present study: 28 cases obtained from the screening cohort (64% male; mean age 65 years, SD 6.5) and 90 cases obtained from the referral cohort (58% male; mean age 69 years, SD 9.8). The mean FIT results found were higher in the referral cohort (829 ± 302 ng/mLvs 613 ± 368 ng/mL,P = 0.02). Tissue tumor stage (T stage) distribution was dif-ferent between both populations [screening population: 13 (46%) T1, eight (29%) T2, six (21%) T3, one (4%) T4 carcinoma; referral population: 12 (13%) T1, 22 (24%) T2, 52 (58%) T3, four (4%) T4 carcinoma], and higher T stage was significantly associated with higher FIT results (P < 0.001). Per tumor stage, no significant difference in mean FIT results was observed (screening vs referral: T1 498 ± 382 ng/mL vs 725 ± 374 ng/mL, P = 0.22; T2 787 ± 303 ng/mL vs 794 ± 341 ng/mL, P = 0.79; T3 563 ± 368 ng/mLvs 870 ± 258 ng/mL,P = 0.13; T4 not available). After correction for T stage in logistic regression analysis, no significant differences in mean FIT results were observed between both types of cohorts (P = 0.10). CONCLUSION: Differences in T stage distribution largely explain differences in FIT results between screening and referral cohorts. Therefore, FIT results should be reported according to T stage.