Timing of postoperative radiation therapy for major salivary gland cancers

Background: The impact of timing of PORT initiation for major salivary gland cancers on survival is unknown. We aim to examine the impact of PORT timeliness on overall survival (OS) of patients with major salivary gland cancers. Methods: This was a cross-sectional analysis using data from the National Cancer Database (2004–2017) and included patients with major salivary gland cancer treated with surgery and PORT. Results: In total, 5701 patients were included (3133 [55%] male, 4644 [82%] white, mean age 59 ± 16 years). For the overall cohort, PORT >6 weeks was not associated with decreased OS (1.00 aHR, 95% CI 0.89–1.11). When specifically examining patients with mucoepidermoid carcinoma, PORT >6 weeks was associated with a decreased OS (1.27 aHR, 95% CI 1.01–1.58). Conclusions: Overall, this analysis did not demonstrate a survival benefit for initiating PORT within 6 weeks for patients with salivary gland malignancies. Subset analysis did support initiating PORT within 6 weeks after resection for patients with mucoepidermoid carcinomas. This was not demonstrated in other major salivary gland cancer histologies.