Abstract
BACKGROUND: The benefit of postoperative chemoradiotherapy (CRT) over radiotherapy (RT) alone remains unclear for resected locally advanced head and neck squamous cell carcinoma (LA-HNSCC) patients with intermediate risk(s) such as pT3 or pT4 primary, pN2 or pN3 nodal disease, nodal disease in levels IV or V, perineural invasion (PNI), and lymphovascular invasion (LVI). This study aims to evaluate the benefits of postoperative CRT in patients with multiple intermediate risks. METHOD: LA-HNSCC patients who underwent curative surgery with intermediate risk at our institution were identified. A propensity score-matched (PSM) method was performed using treatment, sex, age, AJCC staging, LVI, and PNI as covariates. RESULT: A total of 162 eligible patients were identified. After PSM, 48 patients were classified into CRT and RT groups, respectively. Baseline characteristics and treatment were well balanced. In the CRT group, most patients received cisplatin-CRT (67%). Patients with 1, 2, and ≥ 3 intermediate risk factors exhibited significantly different event-free survival (EFS) (7.2 vs. 3.8 vs. 1.9 years; p = 0.007), with a trend towards differences in overall survival (OS) (p = 0.068). The median OS of the postoperative RT and CRT groups was not significantly different (4.5 vs. 5.0 years; p = 0.950). Similarly, the median EFS was not significantly different (p = 0.634). No EFS and OS benefits were demonstrated in patients with ≥ 2 intermediate risk factors treated with CRT compared to RT alone. CONCLUSION: In our PSM study, LA-HNSCC patients with intermediate risk(s) did not benefit from postoperative CRT compared to RT alone. Although patients with multiple intermediate risks had significantly worse survivals, postoperative CRT did not improve OS and EFS. The results of this study may support avoiding unnecessary acute and late toxicity associated with adding chemotherapy to postoperative RT in patients with intermediate risk(s).