The effect of adjuvant radiotherapy on clinical outcomes in early major salivary gland cancer

Background This study investigated the effects of adjuvant radiotherapy on outcomes in early-stage major salivary gland cancers. Methods A total of 655 patients were identified, including 355 (54.2%) received adjuvant radiotherapy and 300 (45.8%) had surgery alone. The effect of adjuvant radiotherapy on 5-year locoregional recurrence and disease-specific survival (DSS) was calculated using the Kaplan-Meier method, Wilcoxon rank sum test, and Cox proportional hazards model. Results There were no significant differences in locoregional recurrence and DSS between patients receiving adjuvant radiotherapy and those not in both univariate and multivariable analysis. Although patients with positive margin status had a higher locoregional recurrence and those with moderate/poor differentiation had a worse DSS, stratified analysis still indicated there were no protective effects from the use of adjuvant radiotherapy. Conclusions The use of adjuvant radiation therapy was not associated with improved locoregional recurrence and DSS, even for those with high-risk histopathological factors.