Abstract
BACKGROUND: The role of radiation therapy in patients with distant metastatic squamous cell carcinoma of the head and neck (mHNSCC) is unclear. In this study, we compare the differences in survival among mHNSCC patients treated with chemotherapy plus radiotherapy (RT) vs. chemotherapy alone. MATERIALS AND METHODS: This study included patients with distant mHNSCC recruited from 2 cohorts: The Surveillance, Epidemiology, and End Results (SEER [N=885]) database and a Chinese single-institution registry in Sun Yat-sen University Cancer Center (SYSUCC [N=60]). The SEER cohort included 600 patients received RT plus chemotherapy and 285 patients received chemotherapy alone; in the SYSUCC cohort, 40 patients received RT plus chemotherapy and 20 patients received chemotherapy alone were recruited. The period of data collection for the SEER study was from January 2010 to December 2015, and that for SYSUCC was from January 2010 to December 2020. The study's primary outcome was overall survival (OS), with disease-specific survival (DSS) as a secondary outcome. RESULTS: Of the 885 patients in the SEER cohort, the addition of RT to chemotherapy increased one-year OS from 46.6% to 56.0% compared with chemotherapy alone (P =0.009) and from 10.4% to 25.1% for three-year OS (P <0.001). Patients who received RT in addition to chemotherapy were also more likely to have better three-year DSS than those who received chemotherapy alone (28.9% vs. 14.0%, P<0.001). Similarly, in the SYSUCC cohort, patients who received chemotherapy plus RT had better three-year OS than chemotherapy alone (62.8% vs. 21.0%, P=0.003). The addition of RT to chemotherapy increased median OS among patients with mHNSCC from 10 months to 13 months in the SEER cohort and from 14 months to 29 months in the SYSUCC cohort. CONCLUSION: Radiotherapy in addition to chemotherapy significantly improved OS and DSS in patients with mHNSCC.