Prevalence of pathogenic germline cancer risk variants in testicular cancer patients: Identifying high risk groups

Background: Germline studies in testicular cancer have focused on unselected populations but so far have not led to recommendations for testicular cancer screening. Objective: Herein, we hypothesized that men with testicular cancer and an additional risk factor for hereditary cancer predisposition carry a higher rate of pathogenic variants than men with testicular cancer without another risk factor. Methods and Results: 187 patients with a personal history of testicular cancer underwent germline testing via Invitae. Patients were divided into low-risk and high-risk patients. Low-risk patients (n=83) had testicular cancer as their only primary malignancy without a family history of testicular cancer. High-risk patients (n=104) had additional primary malignancies and/or a family history of testicular cancer. 23.1% of patients harbored pathogenic germline variants with 19.6% carrying actionable variants. Among low-risk patients, 13.5% carried pathogenic variants versus 29.9% in the high-risk cohort. Of patients with a family history of non-testicular cancers and a personal history of additional primary malignancies, 32% harbored pathogenic variants. Conclusion: High-risk patients are twice as likely to harbor pathogenic variants compared to low-risk patients. Importantly, patients with a family history of cancer and other primary malignancies represent a subset of patients that may benefit from genetic evaluation.