Aspirin use and survival in head and neck squamous cell cancer (HNC) patients.

Abstract

6042 Background: The phosphatidylinositol-3-kinase (PI3K) signaling pathway is the most common genetic alteration in HNC, particularly in oropharynx cancers (OPC). Up-regulation of the PI3K pathway enhances the production of prostaglandins inhibiting apoptosis in cancer cells. We hypothesized that aspirin (ASA) improves survival in HNC patients (pts) by counteracting the effects of prostaglandins. Methods: This is an IRB-approved retrospective cohort study of 584 veterans with HNC treated at the Washington DC Veterans Affairs Medical Center between 1995 and 2015. Charts were reviewed for clinical-pathologic and treatment data; recurrence/distant metastases; cause of death; and for the number, date and dose of ASA prescriptions. Pts who filled more than one prescription, excluding refills, after diagnosis of HNC were considered ASA users. All others were considered non-ASA users. The Kaplan-Meier method and log-rank test were used to compare disease-free survival (DFS) and disease-specific survival (DSS) between users and non-users. Results: 332 pts met inclusion criteria. Primary subsites included oropharynx (n = 146), larynx (n = 105), oral cavity (n = 62), and hypopharynx (n = 19). 86 pts were ASA users after diagnosis (25.9%) and more likely to be older (p = 0.002), African American (p = 0.03), never-alcohol users (p = 0.044), and have early stage cancer (I/II; p < 0.0005) compared to non-ASA users. Among all HNC pts, ASA users demonstrated significantly better 5-year (y) DSS (82%) compared to non users (43%; p = 0.009). 5-y DFS was also significantly higher among users (72%) vs non users (39%; p < 0.001). Among the OPC pts, 5-y DSS was higher for ASA users (74%) vs non users (41%; p = 0.024). 5-y DFS was also better for users (72%) vs non users (39%; p = 0.004). For stages III and IV, 5-y DFS was significantly higher among ASA users (64%) vs non users (44%; p = 0.035). 5-y DSS was higher as well in users (69%) vs non users (44%) but p = 0.098. On multivariate analysis, aspirin use remained an independent prognostic factor associated with improved DSS and DFS when accounting for age, race, gender, subsite, stage, tobacco and alcohol use. Conclusions: Aspirin use following diagnosis and curative treatment of HNC is associated with improved DSS and DFS.