Oropharyngeal squamous cell carcinoma: Prognostic factors for development of distant metastases and oncological outcomes

Background: Distant metastasis (DM) development in Oropharyngeal Squamous Cell Carcinoma (OPSCC) represents an important prognostic factor. The identification of a phenotype of metastatic patients may better define therapeutic and follow-up programs. Methods: We included 408 patients with OPSCC, non-metastatic at the time of diagnosis, and treated with curative intent. The Overall Survival (OS) analyses were performed and the impact of developing DM on survival was analyzed through Cox proportional-hazard regression model. Results: 57 (14%) patients develop DM. 302 (74%) were p16+ OPSCC and 35 of them experienced DM. Advanced clinical stage, smoking, p16-status, response to primary treatment, and loco-regional relapse influence the DM rate. Only in the p16+ group, DM onset results in a greater impact on OS (p < 0.0001). Lung metastases have a better OS compared to non-pulmonary ones (p = 0.049). Conclusion: This retrospective study shows a possible stratification of OPSCC patients based on the risk of the development of DMs.