Deficiencies in germline genetic testing in young-onset colorectal cancer patients

Young-onset colorectal cancer (YO-CRC) patients have high rates of pathologic genetic variants on germline testing, however it is unclear what factors are associated with genetic testing completion. We performed a retrospective review of YO-CRC patients aged ≤50 years between 2014 and 2021 who received the entirety of their cancer care at a single institution. The primary outcome was completion of germline multigene panel testing. Variables were examined for association with germline multigene panel testing. Among 100 YO-CRC patients, only 31 ​% (n ​= ​31) completed genetic testing. Testing rates did not differ by colorectal cancer stage but were significantly higher among patients who received chemotherapy (39.8 ​% vs 5.9 ​%; p ​= ​0.01) and in patients with increasing number of relatives with a family history of cancer (p ​