Gérard Durand

Variations between endoscopists in rates of detection of colorectal neoplasia and their impact on a regional screening program based on colonoscopy after fecal occult blood testing

BACKGROUNDnThere are few data about the performance variability among endoscopists participating to nationwide or regionwide colorectal cancer screening programs.nnnOBJECTIVEnTo assess the variability of neoplasia detection rates among endoscopists participating in a regional colorectal cancer screening program based on colonoscopy after biennial fecal occult blood testing (FOBT).nnnDESIGNnTwo rounds of colonoscopy were performed: round 1 took place in 2003 and 2004, and round 2 took place in 2005 and 2006. Secondary analysis of colonoscopy findings from the first 2 rounds was performed by using data drawn from all endoscopists who performed more than 30 colonoscopies in each round. Detection rates were adjusted for patient age and sex, and logistic regression analyses were conducted including these 2 variables and round number (1 or 2).nnnSETTINGnDistrict of Ille-et-Vilaine in Brittany (population >900,000) between 2003 and 2007.nnnMAIN OUTCOME MEASUREMENTSnThe per-endoscopist adjusted rates of colonoscopies with at least 1, 2, or 3 adenomas, 1 adenoma 10 mm or larger, or a cancer.nnnRESULTSnAmong the 18 endoscopists who performed 3462 colonoscopies, the adjusted detection rates were in the following ranges: at least 1 adenoma, 25.4% to 46.8%; 2 adenomas, 5.1% to 21.7%; 3 adenomas, 2.7% to 12.4%; 1 adenoma 10 mm or larger, 14.2% to 28.0%; and cancer, 6.3% to 16.4%. Multivariate analyses showed that the endoscopist was not an independent predictor of cancer detection, but was an independent predictor of detecting adenomas, regardless of category; the R(2) of the models ranged from 6% to 13% only.nnnLIMITATIONSnOther factors known to influence colorectal neoplasia occurrence and withdrawal time could not be taken into account.nnnCONCLUSIONSnIn a screening program with a high compliance rate with colonoscopy after FOBT, interendoscopist variability had no effect on cancer detection, but did influence identification of adenomas. The clinical impact of such findings merits further evaluation.

Yield of High-Grade Dysplasia Based on Polyp Size Detected at Colonoscopy: A Series of 2295 Examinations Following a Positive Fecal Occult Blood Test in a Population-Based Study

PURPOSE: The aim was to determine the rate of high-grade dysplasia among patients with all adenomas, and its prevalence in patients with adenomas of different sizes in a well-defined population-based study. POPULATION AND METHODS: We performed a secondary analysis of the 2295 colonoscopies performed following a positive fecal occult blood test result during the first round of colorectal cancer screening in one French district. The rates of high-grade dysplasia were calculated for 3 size categories of adenoma (diminutive, ≤5 mm; small, 6–9 mm; large, ≥10 mm). Predictive factors for high-grade dysplasia were assessed by univariate and multivariate analyses. RESULTS: A total of 1284 adenomas were detected in 784 subjects. High-grade dysplasia was present in 32.1% of the 784 subjects and in 2.7%, 16.0%, and 51.1% of those whose adenomas were diminutive, small, and large, respectively. Among subjects with no more than 2 small adenomas, the proportion of those with high-grade dysplasia was 12.4%. Both adenoma size and a villous component within adenomas were found to be independent predictive factors for high-grade dysplasia by multivariate analysis. CONCLUSIONS: Because of the high rate of high-grade dysplasia among small adenomas, our results reinforce the need to remove all small adenomas detected at colonoscopy. Furthermore, the results suggest that opting for CT colonography surveillance instead of colonoscopic removal among subjects with one or 2 small polyps revealed by CT colonography would have led to missed high-grade dysplasia in 12.4% of them.

The positive predictive value of guaiac faecal occult blood test in relation to the number of positive squares in two consecutive rounds of colorectal cancer screening.

The aim of this study was to define the positive predictive values of a positive guaiac faecal occult blood test according to the number of positive squares, in two consecutive rounds of colorectal cancer mass screening in a French region. A total of 4172 colonoscopies were analyzed. Sex, age, number of positive squares, and colonoscopic and histopathologic findings were studied. In the results obtained, 76.6% of positive tests were positive with one or two squares. The number of positive squares was not related to sex, age and rank of participation. The positive predictive value for cancers and adenomas increased significantly with age, sex (male) and number of positive squares from 6.6% (one to two squares) to 27.6% (five to six squares) and from 15.2% to 22.2%, respectively. Cancer was diagnosed 211 times (54.1%) and advanced neoplasia was diagnosed 696 times (65.3%) following positive tests with one to two squares. The TNM stage of cancer increased significantly with the number of positive squares: 85.8% of stages 0–1–2 for one to two positive squares and 66.3% for five to six positive squares (P<0.001). Multivariate analysis showed an increased risk of cancer and advanced neoplasia for male patients and aged persons. The number of positive squares significantly increased the risk of cancer (odds ratio=4.6 for five to six positive squares) and the risk of advanced neoplasia (odds ratio=2.9). Age, sex and number of positive squares were independent predictive factors of positive guaiac faecal occult blood test. The proportion of TNM stages 3–4 was significantly higher in those with five to six positive squares. Performing a complete colonoscopy in every individual having a positive test, especially aged men with a high number of positive squares, should be a priority in any screening programme.

Neoplasia detection rates after positive fecal occult blood test results are not affected by endoscopy center: a population-based study

BACKGROUNDnWe previously showed a significant variability in adenoma detection among colonoscopists who were participating in a mass screening program. The reasons for such variability remain largely unknown.nnnOBJECTIVEnTo study intercenter variations in neoplasia detection.nnnDESIGN AND SETTINGnSecondary analyses of colonoscopy findings from the 2 first rounds of a French screening program: logistic regressions and repeated-measures analyses of variance.nnnMATERIALnA total of 3487 colonoscopies performed by all 19 endoscopists who performed 30 examinations or more per round at 8 centers (6 private, 2 public).nnnMAIN OUTCOME MEASUREMENTSnProbabilities of detecting 1, 2, or 3 or more adenomas, 1 adenoma 10 mm or larger, or colorectal cancer, as well as the corresponding adjusted (for patient age and sex) per-center detection rates.nnnRESULTSnEndoscopy centers were not significant predictors of the probability of detecting any category of neoplasia with the exception of the 2 adenomas or more category (P < .005). The ranges of the adjusted detection rates for each of these categories were 33.1% to 43.1%, 11.1% to 21.6%, 3.6% to 8.1%, 16.3% to 23.6%, and 8.3% to 12.6%, respectively. When the colonoscopies that were performed by the 11 endoscopists who performed 30 examinations or more per center in 2 or more centers were separately analyzed, no intercenter statistically significant variability was observed with the exception of 1 endoscopist and the 1 adenoma category. In a subgroup of 1100 colonoscopies performed by 6 endoscopists who were working at the same 3 centers, intercenter variability was not statistically significant.nnnLIMITATIONSnType II error because of sample sizes.nnnCONCLUSIONSnIn our setting, intercenter variability did not explain interendoscopist variability for neoplasia detection rate.