Germline Testing of Colorectal Cancer Patients Uncovers High Rate of Clinically Actionable Genetic Variants

Expanding germline multigene panel testing to a broader group of colorectal cancer (CRC) patients could uncover additional individuals with clinically actionable genetic variants, a new study in JCO Precision Oncology has found. Researchers from the University of Pennsylvania and Invitae conducted a retrospective cohort study of adults with CRC who underwent multigene panel testing of more than 10 genes to determine the yield and clinical impact of testing on a large, diverse patient population. In their cohort of 34,244 individuals, 14.2 percent had a pathogenic or likely pathogenic variant and 11.9 percent had a clinically actionable pathogenic variant. Variants of uncertain significance were identified in 38.2 percent of patients and were more commonly found among Black, Asian, and Hispanic individuals. The researchers note that germline testing is generally limited to a portion of high-risk CRC patients but say that their finding of a high rate of pathogenic variants among a diverse population argues for broadening testing criteria. "Herein, we provide MGPT data from the largest cohort to date of patients with CRC, where we show that there are high rates of clinically actionable variants among patients with CRC, independent of the age at the time of testing, the number of genes on the panel, and race/ethnicity," the researchers write.