Metachronous second primary neoplasia in oropharyngeal cancer patients: Impact of tumor HPV status. A GETTEC multicentric study.

Introduction: Patients with oropharyngeal squamous cell carcinoma (OPSCC) display a significant risk to develop a metachronous second primary neoplasia (MSPN). HPV and non-HPV-related OPSCC are 2 distinct entities with biological, clinical and prognostic differences. The aims of our study were to analyze the impact of tumor HPV status and other relevant clinical factors, such as tobacco and/or alcohol (T/A) consumption, on the risk and distribution of MSPN in OPSCC patients and to assess the impact of MSPN on patient survival.

Material And Methods: All OPSCC patients treated from 2009 to 2014 were included in this multicentric retrospective study. P16 immunohistochemical expression was used as a surrogate maker of tumor HPV status. The impact of tumor p16 status on the risk of MSPN was assessed in uni- and multivariate analyses. Overall survival (OS) was determined by Kaplan-Meier analysis.

Results: Among the 1291 patients included in this study, 138 (10.7%) displayed a MSPN which was preferentially located in the head and neck area (H&N), lung and esophagus. Multivariate analyses showed that p16- tumor status (p = 0.003), T/A consumption (p = 0.005) and soft palate tumor site (p = 0.009) were significantly associated with a higher risk of MSPN. We found no impact of p16 tumor status on the median time between index OPSCC diagnosis and MSPN development, but a higher proportion of MSPN arising outside the H&N, lung and esophagus was found in p16 + than in p16- patients. MSPN development had an unfavorable impact (p = 0.04) on OS only in the p16 + patient group.

Conclusion: P16 tumor status and T/A consumption were the main predictive factors of MSPN in OPSCC patients. This study provides crucial results with a view to tailoring global management and follow-up of OPSCC patients.