The Oncological Outcome of Postoperative Radiotherapy in Patients with Node-Negative Early-Stage (T1/T2/N0) Oral Squamous Cell Carcinoma and Perineural Invasion: A Meta-Analysis

Abstract

Objective: To evaluate the impact of postoperative radiotherapy (PORT) on oncological outcomes in node-negative early-stage oral squamous cell carcinoma (OSCC) with perineural invasion (PNI). Methods: A systematic review and meta-analysis was conducted using the PubMed, EMBASE, and Scopus databases for the period from 2000 to 2024. Studies comparing PORT versus observation in pN0 early-stage OSCC with PNI were included. Oncological outcomes assessed included overall survival (OS), disease-free survival (DFS), and local control (LC). A random-effects model was used to calculate log odds ratios, and heterogeneity was assessed using tau2, chi2, and I2 statistics. Results: Seven retrospective studies comprising 522 patients (281 PORT, 241 no-PORT) were included. The 3-year overall survival (OS) was 86.3% in the PORT group compared to 71.1% in the no-PORT group (logOR = −1.03, p = 0.0012), while the 5-year OS was 88.1% versus 77.3% (logOR = −0.97, p = 0.0061). Disease-free survival (DFS) also favored PORT, with 3-year DFS at 86.3% versus 58.1% (logOR = −1.19, p < 0.001) and 5-year DFS at 86.3% versus 55% (logOR = −0.78, p = 0.003). Local control (LC) was higher in the PORT group, with 3-year LC rates of 89% compared to 72.2% in the no-PORT group (logOR = −1.13, p = 0.025). Conclusions: PORT significantly improves OS, DFS, and LC in node-negative early-stage OSCC with PNI as the sole adverse feature.