Time to reduce the burden of removing diminutive polyps in colorectal cancer screening.

Much polypectomy and also surveillance could be avoided at essentially no risk by abandoning polypectomy of diminutive polyps (by far the most commonly detected type of polyps) altogether, at least in screening programs that foresee some type of repeated screening. In their very well conducted systematic review, Vleugels et al identified and reviewed studies reporting on the natural history of diminutive (1-5 mm) and small (6-9 mm) colorectal polyps. Based on the limited evidence from the available studies, the estimated progression rates to advanced adenomas or colorectal cancer (CRC) were very low. The results seem to support suggestions that, overall, removal of diminutive and small polyps at screening colonoscopy may do more harm than good because the increased risk of adverse events and increased burden of histologic examinations and surveillance may be too high compared with the expected minimal gain in protection from CRC. The joint consideration with other existing epidemiologic evidence not only supports proposed and currently debated “diagnose and leave” or “resect and discard” strategies but gives further support to questioning any resection of nonneoplastic and adenomatous diminutive polyps. Adherence to the so-called hierarchies of evidence might suggest that a definite answer about the benefits and harms of resection of diminutive and small polyps could come only from randomized controlled trials (RCTs) comparing offers of screening colonoscopy with or without the removal of diminutive and small polyps and including CRC mortality as a primary endpoint. However, this rather dogmatic choice of design would in this instance be of no use to inform clinical guidelines and public health policy, neither in the foreseeable future nor in the long run. The trials would be extremely inefficient and perhaps even impossible to conduct. Apart from their very long duration, requiring more than 10 years of follow-up, the expected very low 10-year CRC incidence and mortality among people with diminutive or small polyps only (but no large polyps) would necessitate prohibitively large sample sizes for disclosing any relevant differences in CRC mortality with reasonable power (or confirming equivalence with reasonable confidence). When the results of such RCTs were to become available, endoscopic technology or even other diagnostic approaches would be expected to have advanced to such an extent that results pertaining to diminutive and small polyps detected and characterized by technologies