Postoperative radiotherapy with or without concurrent chemotherapy for oral squamous cell carcinoma in patients with three or more minor risk factors: a propensity score matching analysis

To investigate the advantage of concurrent chemotherapy with postoperative radiotherapy (RT) of oral squamous cell carcinoma (OSCC) in patients with three or more minor risk factors. Minor risk factors included pT4 disease, pN1 disease, margin ≤ 4 mm, poor differentiation, perineural invasion, vessel or lymphatic invasion, and tumor invasion depth ≥ 11 mm. Surgery was the primary treatment, followed by RT or concurrent chemoradiation (CCRT). After propensity score matching, 34 patients in each treatment group were selected for comparison. The median follow-up for living patients was 86.4 months (range: 47–189 months). The 5-year overall survival of the RT and CCRT groups was 35.3% and 67.2% (p = 0.018), respectively. The 5-year recurrence-free survival of the RT group and CCRT group was 42.6% and 75.4% (p < 0.01). Postoperative CCRT for patients with three or more minor risk factors increased recurrence-free and overall survival.