No survival benefit from adding chemotherapy to adjuvant radiation in advanced major salivary gland cancer.

This study aimed to compare survival of patients with advanced major salivary gland cancers treated with adjuvant chemoradiation therapy (CRT) versus radiotherapy (RT) alone, after surgical resection. The Taiwan Cancer Registry database was used to identify patients (2009-2017) with advanced (T3-4 or nodal positivity) major salivary gland cancers, treated post-surgically with adjuvant CRT or RT alone. Overall survival (OS) and disease-specific survival (DSS) evaluated using Kaplan-Meier. Stratified analyses conducted on clinicopathological features. A total of 395 patients were analyzed: 178 (45.1%) received adjuvant CRT; 217 (54.9%) received adjuvant RT alone. Median radiation dose was 66 Gy in 33 fractions. Cisplatin was most common chemotherapy regimen. After a median follow-up of 3.37 years, there was no significant difference in OS or DSS (p = 0.1354 and 0.3361, respectively) between groups. Adding chemotherapy to adjuvant RT was not significantly associated with improved OS (adjusted hazard ratio [aHR] 0.94; 95% CI 0.72-1.23) and DSS (aHR 0.96; 95% CI 0.72-1.28). Stratified analysis of clinicopathological features found no significant advantages for improved OS or DSS from adding chemotherapy to adjuvant RT. Thus, in this population database, the use of chemotherapy provided limited survival benefits in advanced major salivary gland cancers after surgical resection.