The role of concomitant chemoradiotherapy in AJCC 7th edition T1-2N1 oropharyngeal carcinoma in the human papillomavirus era.

BACKGROUND: Radiotherapy (RT) without chemotherapy is considered a standard of care for the management of American Joint Committee on Cancer (AJCC) 7th edition (7E) T1-2N1 oropharyngeal squamous cell carcinoma (OPSCC). Recent data suggests concurrent chemoradiation (CCRT) may benefit these patients but did not include human papillomavirus (HPV) status. Given the radiosensitivity differences between HPV-positive versus HPV-negative OPSCC, the effect of chemotherapy may differ in these patients. METHODS: We analyzed patients in the National Cancer Database diagnosed between 2010 and 2015 with AJCC 7E stage cT1-2N1M0 OPSCC and known HPV status undergoing definitive RT or CCRT. RESULTS: Overall, 1964 patients were included, including 1297 (66%) HPV-positive and 667 (34%) HPV-negative patients. 66% received CCRT and 34% received RT alone. In multivariate analysis, CCRT was associated with improved survival compared with RT alone (hazard ratio [HR], 0.70; 95% confidence interval [CI], 0.57-0.87; P = 0.001). In propensity score-matched cohorts, 4-year overall survival was 87.4% vs 78.4% in HPV-positive patients receiving CCRT and RT alone, respectively (P = 0.002), and 65.5% vs 58.9% in HPV-negative patients, respectively (P = 0.2). There was no evidence that HPV-positivity diminished the association between CCRT and longer survival (HR, 0.57; 95% CI, 0.42-0.81) versus what was observed in HPV-negative patients (HR, 0.86; 95% CI, 0.64-1.16) (interaction P = 0.06). CONCLUSIONS: CCRT is associated with improved survival in AJCC 7E T1-2N1 OPSCC. Despite the radiosensitivity of HPV-positive OPSCC, the association of CCRT with improved survival for T1-2N1 HPV-positive OPSCC was at least as strong, if not stronger, than what was observed in HPV-negative patients.