Primary Care Implications of the Expanded National Guidelines for Germline Testing of Patients Previously Diagnosed with Colorectal Cancer

Colorectal cancer (CRC) is among the most common cancers diagnosed in the United States. Most patients are cured, have completed their routine surveillance in oncology clinics, and are being followed by primary care clinicians (PCCs). Those providers are tasked with discussing with these patients genetic testing for inherited cancer-predisposing genes that are called PGVs. Recently, the National Comprehensive Cancer Network (NCCN) Hereditary/Familial High-Risk Assessment: Colorectal Guidelines expert panel updated their recommendations for genetic testing. It is now recommended that all patients diagnosed with CRC before age 50 be tested and patients diagnosed at age 50 or older be considered for multigene panel testing (MGPT) for inherited cancer-predisposing PGVs. Here, I discuss the basis for the NCCN expanded genetic testing recommendations and highlight the salient controversies related to genetic testing. I also review the literature that suggests that PCCs identified more training as the measure needed before they are comfortable having complex discussions related to genetic testing with their patients.