Adenoma Detection Rate Says It All in FIT-Positive Patients
Douglas K. Rex, MD, MASGE, reviewing Denis B, et al. Endosc Int Open 2022 May 23.
This is a study of detection indicators in 13,067 fecal immunochemical test (FIT)-positive colonoscopies performed by 80 community gastroenterologists. The cutoff for FIT positivity was 30 μg Hb/g feces, but the test was quantitative. There was good correlation between the adenoma detection rate (ADR) and essentially all other detection predictors, including proximal serrated lesion detection. Forty-eight endoscopists had an ADR of ≥55%, and 46 had proximal serrated lesion detection ≥4%. Polyp detection rate (PDR) did not substitute well for ADR, even retrospectively, because the ADR to PDR ratio varied from 0.61 to 0.93.
The authors suggest that the maximum ADR target should be 70% because there was a loss of specificity for endoscopists with ADR >70%, who removed non-neoplastic lesions in 39.5% of patients versus 21.4% for those with ADR ≤70%. A 10 μg/g increase in fecal hemoglobin concentration was associated with higher ADR (odds ratio, 1.02).
COMMENTThe French-organized CRC screening program previously used a recommended ADR threshold of 45% for FIT-positive patients, which results in 12.5% of endoscopists falling below the threshold. Moving the recommended ADR threshold to 55% would result in 40% of endoscopists being low detectors, which seems appropriate and reasonable given that the endoscopist is the most important adjustable predictor of postcolonoscopy cancer.
This study is the first to associate stool hemoglobin concentration with ADR, and it has implications for the expected ADR performance in FIT-positive populations in the U.S., where a 20 μg Hb/g feces cutoff for positivity is used and results are reported as only positive or negative. The study raises an important consideration of a maximum appropriate ADR, which is different than an aspirational ADR. The concept of a maximum ADR illuminates the poor specificity that could accompany the use of an aspirational ADR only. Economic incentives (payment for polypectomy, regardless of histology) can also contribute to very high polypectomy rates that include excess non-neoplastic polyps.
Note to readers: At the time we reviewed this paper, its publisher noted that it was not in final form and that subsequent changes might be made.
CITATION(S)
Denis B, Gendre I, Tuzin N, et al. Adenoma detection rate is enough to assess endoscopist performance: a population-based observational study of FIT positive colonoscopies. Endosc Int Open 2022 May 23. (Epub ahead of print) (https://doi.org/10.1055/a-1859-8277)
