p16 Influence on Laryngeal Squamous Cell Carcinoma Relapse and Survival.

OBJECTIVE: (1) To identify p16 protein in laryngeal squamous cell carcinoma (LSCC) specimens and to correlate it with the presence of human papillomavirus (HPV) found in these specimens from a previous study. (2) To analyze p16 impact on 10-year overall and disease-free survival. STUDY DESIGN: Retrospective case series with oncologic database chart review. SETTING: Academic tertiary care hospital. SUBJECTS: A total of 123 samples of LSCC (taken from the glottis only) from patients treated with primary surgical resection between 1977 and 2005. METHODS: p16 protein expression was analyzed through immunohistochemistry and compared with the presence of HPV established in our previous studies. Results were compared with histologic, clinicopathologic, and survival parameters, with a 10-year follow-up. RESULTS: Of the samples, 39.02% were positive for p16, but only 11.38% were positive for both p16 and HPV. The p16+ cohort showed a significant improvement in disease-free survival ( P = .0022); statistical significance was not achieved for overall survival. p16+ cases had fewer relapses over time, with no relapses after a 2-year follow-up. Age at the time of diagnosis and tobacco consumption were the only epidemiologic factors that influenced overall survival. CONCLUSION: The expression of p16 protein was a beneficial prognostic factor for disease-free survival among patients with LSCC of the glottis, with no relapses after a 2-year follow-up.