Extracapsular spread in head and neck carcinoma: impact of site and human papillomavirus status.

Extracapsular spread (ECS) in cervical lymph node metastases from head and neck squamous cell carcinoma (SCC) is regarded as an adverse prognostic factor and is often used to select patients who may benefit from adjuvant therapy. The prognostic value of ECS was evaluated for patients with oropharyngeal SCC (OPC; with known p16/human papillomavirus [HPV] status) and for patients with SCC of the oral cavity (OCC). Disease-specific survival (DSS) was assessed among SCC patients with cervical lymph node metastases (n = 347, including 133 patients with OPC and 214 patients with OCC). All patients were treated surgically between 1983 and 2009. ECS status was determined by pathologists at the time of initial pathologic evaluation and confirmed for this study. HPV status of patients with OPC was determined via immunohistochemistry for p16 and in situ hybridization. Among OCC patients, ECS was a significant, independent factor influencing DSS. For OCC patients with ECS, 3-year DSS was 45% (95% confidence interval [CI], 36%-56%); for those without ECS, 3-year DSS was 71% (95% CI, 62%-81%; P = .0018). The effect of ECS was independent of the number of positive lymph nodes as well as other clinical, pathologic, and treatment variables. Of the 133 OPC patients, 76 (57%) were p16-positive and 57 (43%) were p16-negative. ECS status did not correlate with DSS among p16-positive or p16-negative OPC patients. ECS was not associated with worse DSS in p16-positive or p16-negative OPC patients. Adverse prognostic value of ECS in OCC patients was confirmed. Cancer 2013;119:3302-8. © 2013 American Cancer Society.