LAUSR

571Background: Deleterious mutations in adenomatous polyposis coli gene (APC) lead to familial adenomatous polyposis [FAP] and attenuated FAP (aFAP) syndromes associated with hereditary colorectal cancer (CRC) and extra-colonic neoplasms. Reports suggest only two-third of such patients (pts) comply with recommended screening guidelines. The objective of this study was to assess compliance of FAP/aFAP pts with NCCN recommended guidelines of screening endoscopies and chemoprevention in our population. Methods: Retrospective review of clinical charts of pts with APC mutations, identified through multi-gene panel or single-gene testing, and seen in our NCI designated Comprehensive Cancer Center between 01/2013 and 09/2017. Results: Out of 53 pts with deleterious APC gene mutations, 31 pts (58.5%) had mutations associated with an FAP (27 pts; mean-age 31 years) or aFAP (4 pts, mean-age 33 years) phenotype and were included in analyses. Ten of these 31 pts (32.3%) were diagnosed with FAP after diagnosis of CRC;...