Multitarget Stool RNA Testing—Reply

In Reply We appreciate the Letters from Drs Imperiale and colleagues and Dr Baird. Regarding SSLs of at least 1 cm in size, we are following the most recent US Multi-Society Task Force guidelines, which were cited by Imperiale and colleagues. These guidelines state “Because evidence of the risk of metachronous neoplasia associated with serrated lesions is evolving, whenever possible we have chosen not to include SSPs [sessile serrated polyps] and HPs [hyperplastic polyps] in our definitions of low-risk adenoma, high risk adenoma, and advanced neoplasia, and will refer to these lesions separately.” This exclusion of SSPs was mainly due to “concern about pathologists’ consistency in distinguishing SSPs from HPs.” Furthermore, evidence for labeling SSLs of at least 1 cm as high-risk was deemed “weak,” due to “very low quality of evidence,” and was based on a single retrospective study. Most evidence supporting the risk of postcolonoscopy CRC comes from patients with traditional serrated adenomas, which we included in the advanced adenoma category. As such, we have chosen to follow the US Multi-Society Task Force guidelines and reported these lesions separately.