HPV Biomarkers in Oral and Blood‐Derived Body Fluids in Head and Neck Cancer Patients

Oral HPV DNA and circulating tumor (ct) HPV DNA in plasma were evaluated as potential biomarkers for HPV-associated head and neck cancer (HNC). Samples from HNC patients (n = 132), including 23 oropharyngeal cancers (OPC), and non-HNC controls (n = 10) were analyzed. HPV status was determined using a multiplex bead-based test (E7-MPG) applied to formalin-fixed paraffin-embedded (FFPE) tissues (n = 90), plasma (n = 141), gargle samples (n = 141), and oral swabs (n = 142). HPV DNA was detected in 25.8% of HNC tissues, 12% of plasma samples, 20.6% of gargles and 7% of oral swabs with HPV16 as the most prevalent genotype. Among OPC cases, HPV16 DNA was found in 71.4% of FFPE samples. High concordance was observed between paired OPC tissues and plasma (91.3%) or gargles (95.2%), with moderate concordance for oral swabs (59.1%). Gargle samples alone demonstrated a 100% detection rate for HPV16-positive OPC, regardless of the cT stage, outperforming plasma (86.7%). Combined oral gargle and plasma analyses detected all HPV-positive OPC cases (7/7) at the early cT1 stage. These findings highlight the limited involvement of HPV in non-oropharyngeal HNC compared to OPC, and support gargle and plasma samples as minimally invasive diagnostic tools for detecting HPV-associated OPC.