Multitarget Stool RNA Test for Noninvasive Detection of Colorectal Neoplasias in a Multicenter, Prospective, and Retrospective Cohort.

Introduction: Effective colorectal cancer (CRC) prevention and screening requires sensitive detection of all advanced neoplasias (CRC and advanced adenomas [AA]). However, existing noninvasive screening approaches cannot accurately detect adenomas with high sensitivity.

Methods: Here, we describe a multifactor assay (RNA-FIT test) that combines 8 stool-derived eukaryotic RNA biomarkers, patient demographic information (smoking status), and a fecal immunochemical test (FIT) to sensitively detect advanced colorectal neoplasias and other non-advanced adenomas in a 1,305-patient, average-risk, prospective cohort. This cohort was supplemented with a 22-patient retrospective cohort consisting of stool samples obtained from patients diagnosed with AA or CRC before treatment or resection. Participants within these cohorts were evaluated with the RNA-FIT assay and an optical colonoscopy. RNA-FIT test results were compared with colonoscopy findings.

Results: Model performance was assessed through 5-fold internal cross-validation of the training set (n = 939) and by using the model on a hold out testing set (n = 388). When used on the hold out testing set, the RNA-FIT test attained a 95% sensitivity for CRC (n = 22), 62% sensitivity for AA (n = 52), 25% sensitivity for other non-AA (n = 139), 80% specificity for hyperplastic polyps (n = 74), and 85% specificity for no findings on a colonoscopy (n = 101).

Discussion: The RNA-FIT assay demonstrated clinically relevant detection of all grades of colorectal neoplasia, including carcinomas, AAs, and ONAs. This assay could represent a noninvasive option to screen for both CRC and precancerous adenomas.