Interactions between clinical factors, p16, and cyclin-D1 expression and survival outcomes in oropharyngeal and hypopharyngeal squamous cell carcinoma.

BACKGROUND: P16 and cyclin-D1 are cell cycle proteins commonly dysregulated in head and neck carcinoma. We assessed their expression, clinicopathological variables, and overall survival (OS) in oropharyngeal and hypopharyngeal squamous cell carcinoma (SCC). METHODS: Clinical characteristics and p16 and cyclin-D1 expression were evaluated in 101 patients with oropharyngeal SCC and 75 patients with hypopharyngeal SCC. Associations with OS were assessed using Cox regression and Kaplan-Meier analysis. RESULTS: Compared to oropharyngeal SCC, patients with hypopharyngeal SCC were older, men, ever-smokers with higher mean Charlson Comorbidity Index (CCI), lower p16 expression, and poorer median OS (24.8 vs 62.3 months; p < .01). In oropharyngeal SCC, CCI (p < .001), cyclin-D1 (hazard ratio [HR] = 3.55; p = .007), current smoking (HR = 5.72; p = .004), and former smoking (HR = 4.12; p = .035) were independently associated with OS. In hypopharyngeal SCC, only nodal and Eastern Cooperative Oncology Group status were associated with OS. CONCLUSION: In oropharyngeal SCC, cyclin-D1 expression is correlated with survival, whereas smoking status and CCI may allow further stratification of outcome.