Germline Genetic Testing in Unselected Squamous and Non-Squamous Head and Neck Cancers

Objective: This study describes the prevalence of pathogenic germline variants (PGVs) in head and neck cancer patients, the incremental yield compared to a guideline-based approach to genetic evaluation, and the uptake of family variant testing. Study Design: Prospective cohort study. Setting: Three tertiary academic medical centers. Methods: Germline sequencing using an 84-gene screening platform among unselected head and neck cancer patients who received care at Mayo Clinic Cancer Centers between April 2018 and March 2020. Results: Amongst 200 patients, the median age was 62.0 years (Q1, Q3: 55, 71), 23.0% were female, 89.0% white/non-Hispanic, 5.0% Hispanic/Latinx, 6% of another race, and 42.0% had prognostic stage IV disease. The most common subsites were the oropharyngeal (45.0%) and salivary glands (12.0%). The most common histology was squamous cell carcinoma (74.5%). Twenty-one patients (10.5%) had a total of 22 PGVs; 20 of the 21 patients (95.2%) did not meet criteria for testing by current guidelines. Regarding penetrance of the 22 PGVs, 11 were high or moderate (most common PMS2 or HOXB13), and 11 were low or recessive (most common MUTYH, WNR, or RECQL4). One patient had a change in care based on an identified PGV. Family variant testing was completed at a rate of 4.8%. Conclusions: Universal gene panel testing identified a PGV in 10.5% of head and neck cancer patients; almost all would have been missed by current guideline-based testing. One of 21 patients had a treatment change due to their PGV, indicating that head and neck cancer treatment decisions are not yet widely informed by germline alterations. Level of Evidence: 3 Laryngoscope, 133:3378–3388, 2023.