Co-overexpression of p21 and Ki-67 in head and neck squamous cell carcinoma relative to a significantly poor prognosis.

BACKGROUND Head and neck squamous cell carcinomas (HNSCC) are treated by surgery or radiotherapy. Tumor cell death-related markers, such as p21 and Ki-67, may predict response to therapy and improve treatment choice. We evaluated and compared the effect of their coexpression between patients treated by surgery or radiotherapy. METHODS Immunohistochemistry for p21 and Ki-67 expression in 144 pharyngeal and laryngeal HNSCC samples was analyzed and correlated with follow-up parameters. RESULTS p21 expression correlated significantly with positive cN classification (p < .001), locoregional relapse (p = .031), and poor overall survival (p = .016), and Ki-67 positivity with poor survival only (p = .025). Coexpressing tumor phenotypes showed the worst survival (p = .009), observed primarily in patients treated by radiotherapy (p = .077). CONCLUSIONS Coexpression of p21/Ki-67 is a strong negative prognostic factor in HNSCC and could be of particular relevance in tumors treated by primary radiotherapy.