Indications for postoperative adjuvant therapy in patients with other risk features in oral squamous cell carcinoma

Postoperative adjuvant therapy (radiotherapy or consideration of concomitant chemoradiotherapy) is recommended for patients with oral squamous cell carcinoma (OSCC) who have other risk features identified on histopathological examination.However, categorizing all patients with other risk features into a single group may not be appropriate.The present study aimed to clarify the indications for postoperative adjuvant therapy in patients with other risk features.This single-center retrospective study enrolled patients with OSCC who underwent primary surgery with simultaneous radical or elective neck dissection between April 2001 and March 2024.Predictor variables included surgical margin, pathological (p) T and pN stages, metastatic level, perineural invasion, vascular invasion and lymphatic invasion (LI).The main outcome variables included disease-specific survival (DSS), overall survival (OS) and recurrence-free survival (RFS).Survival outcomes were analyzed using the Kaplan-Meier method and compared using the log-rank test.Multivariate analyses were performed using Cox regression.The final sample comprised 194 patients [median age, 70 years; age range, 23-93 years; 108 (55.7%) male patients].No significant differences in 5-year DSS, OS or RFS were observed between patients with and without other risk features.Multivariate analysis identified pT3 or pT4 primary tumors and LI as significant independent prognostic factors for poorer DSS and OS.pN2 or pN3 nodal disease and vascular invasion were identified as significant independent prognostic factors for poorer RFS.Postoperative adjuvant therapy was not associated with improved DSS in patients with pT3 or pT4 primary tumors or LI.In conclusion, pT3 or pT4 primary tumors and LI were identified as independent prognostic factors for DSS and OS.These findings may help refine the selection of patients with other risk features who are most likely to benefit from postoperative adjuvant therapy.