Comparison of Survival Estimates Following Recurrence, Persistence, or Second Primary Malignancy in Oropharyngeal Squamous Cell Carcinoma

Objective This study investigated survival among patients with oropharyngeal squamous cell carcinoma (OPSCC) after recurrence, persistence, and second primary malignancies (SPMs). Study Design Retrospective cohort study. Setting Patients were treated at a tertiary cancer center. Subjects and Methods Patients with OPSCC who had completed treatment between 2001 and 2017 were included. Survival estimates of 4 groups of patients were calculated: (1) patients who were disease free after initial treatment, (2) patients who had persistent disease, (3) those with recurrent disease, and (4) patients with SPMs. Cox proportional hazard models and parametric survival analyses (using Weibull distributions) were used to obtain hazard ratios (HRs) and time ratios (TRs). Results The cohort included 364 patients. The crude overall SPM prevalence was 8.2%. Mean overall survival (OS) time in years for patients who remained disease free after treatment was 4.02 years. Among patients who experienced recurrence, the recurrence-free survival (RFS) was 2.58 years while their mean (SD) OS was 3.67 (2.7) years. Participants who experienced persistence had a mean (SD) OS of 1.67 (1.68) years. Patients with observed SPMs had a mean (SD) OS of 6.39 (4.06) years since their primary cancer but shortened survivals of 1.75 (2.34) years since the secondary diagnosis. Differences were present even after accounting for human papillomavirus (HPV) and smoking status. Conclusions Our findings stress the importance of active surveillance as per current National Comprehensive Cancer Network guidelines, irrespective of the HPV status or smoking status. Prospective studies with a larger number of SPM cases and longer follow-up are needed to validate survival trends even beyond 5 years.