Prognostic Significance of a Scoring System Combining p16, Smoking, and Drinking Status in a Series of 131 Patients with Oropharyngeal Cancers.

Background: Tobacco and alcohol are two main risk factors associated with head and neck squamous cell carcinoma (HNSCC). Studies showed that human papillomavirus (HPV) plays a role in the etiology of this cancer. HPV-positive oropharyngeal squamous cell carcinoma (OSCC) patients present in general a better response to conventional therapy and better overall survival (OS). However, OSCC is a heterogeneous disease regarding treatment. This study aimed to identify more effective prognostic factors associated with a poor clinical outcome for OSCC patients to improve treatment selection.

Materials and methods: OSCC patients diagnosed between 2007 and 2017, in two Belgian hospitals, were included. Demographic and clinicopathologic data were extracted from medical records. HPV status was determined through p16 immunohistochemistry. Univariable and multivariable Cox proportional hazard regression analyses allowed to identify variables prognostic for OS and recurrence-free survival (RFS). Kaplan-Meier survival curves have been assessed for survival.

Results: The study included 131 patients. Statistics showed that monotherapies were significantly associated with a shorter OS; p16 overexpression was significantly associated with a weak consumption of tobacco or alcohol, and a high p16 expression was significantly associated with both longer RFS and OS. The study validated that tobacco and alcohol consumption were significantly correlated with poorer RFS and poorer OS. Only p16 expression trended to be significant for RFS when compared to smoking and drinking habits, while p16 upregulation and alcohol use were both vital for OS indicating that p16 is an independent and significant prognostic factor in OSCC patients. Finally, a scoring system combining p16, tobacco, and alcohol status was defined and was significantly associated with longer RFS and longer OS for nonsmoker and nondrinker p16-positive OSCC patients.

Conclusions: This study confirmed that the overexpression of the p16 protein could be viewed as a factor of good prognosis for RFS and OS of OSCC patients. The prognostic significance of a scoring system combining p16 expression, smoking, and drinking status was evaluated and concluded to be a more effective tool to determine therapeutic orientations based on the risk factors for better treatment relevance and survival.