Personalized circulating tumor DNA for monitoring disease status in HPV-negative head and neck squamous cell carcinoma

Many patients with locoregionally advanced HPV-negative head and neck squamous cell carcinoma (HNSCC) relapse. Circulating tumor (ct)DNA has the potential to identify minimal residual disease, but its clinical utility for virus-negative HNSCC is not well understood. A retrospective study at Dana-Farber Cancer Institute and Brigham and Women’s Hospital (both in Boston, MA) evaluated a personalized ctDNA assay during clinical care of patients treated for predominantly newly diagnosed HPV-negative HNSCC. Testing was succesful in 86% of patients. At median follow-up of 5.1 months (range 0.2-15.1), 55% had more than one test result (range 1-7), and 31% remained ctDNA positive after starting treatment. Progression-free survival was significantly worse for patients who were ctDNA positive versus negative post-treatment (HR 7.33; p<0.001); 1-year overall survival rate was 89.1% versus 100% (HR 7.46; p=0.155). The authors conclude that tumor-informed ctDNA testing is feasible in non-viral HNSCC. ctDNA positivity is an indicator of disease progression and associated with inferior survival.