High p16 Expression Predicts a Positive Response to Chemoradiotherapy in Stage IVa/b Head and Neck Squamous Cell Carcinoma

Background: The objective of this study was to evaluate the effect of p16 expression on response tochemoradiation in stage IVa/b head and neck squamous cell carcinoma (HNSCC) patients.
Methods: Weretrospectively identified 64 patients with stage IVa/b HNSCC who received chemoradiation. Eligibility criteriaincluded presence of biopsy-proven stage IVa/b HNSCC without a prior history of chemotherapy or radiotherapy.Immunohistochemistry was used to assess p16 protein expression in pretreatment biopsy specimens.
Results: Ofthe 64 patients, 38 showed high p16 expression, and 50 patients responded to chemoradiotherapy, 32 exhibitinga complete and 18 a partial response. Response was significantly associated with p16 expression (P<0.001)and multivariate analysis indicated that that p16 expression (HR: 2.62, 95%C.I.: 1.14-6.06; P=0.024) was anindependent prognostic factor for overall survival.
Conclusions: High p16 expression predicts a better responseto chemoradiation in patients with stage IVa/b HNSCC.