The following is a summary of “Adjuvant radiotherapy mitigates impact of perineural invasion on oncologic outcomes in early-stage oral cavity squamous cell carcinoma. A multi-institutional analysis of 557 patients,” published in the July 2023 issue of Oral Oncology by Holcomb et al.

The purpose of this study is to determine the prognostic significance of perineural invasion (PNI) in early-stage oral cavity squamous cell carcinoma (OCSCC) and to evaluate the effect of adjuvant radiotherapy on the clinical outcomes of patients with PNI-positive early-stage OCSCC. Retrospective cohort analysis involved pathologic T1-2 N0-1 OCSCC patients who underwent primary surgery with negative margins at seven institutions. 

Disease-free survival (DFS) and locoregional control (LRC) were among the outcomes. Utilizing Cox proportional hazards models, oncologic outcomes were evaluated. Interaction terms have been introduced to evaluate relationships between PNI and adjuvant radiotherapy. Among 557 patients (mean (SD) age: 61.0 (13.9), 47.2% female, 66.6% pathologic T1, 93.5% pathologic N0), 93 had PNI-positive tumors; 87.1% underwent neck dissection and 39.6% were treated with radiotherapy. PNI was linked to reduced DFS and LRC in a multivariable analysis. 

In a multivariable analysis of the entire cohort, adjuvant radiotherapy was not associated with enhanced survival. Among patients with PNI-positive tumors, however, adjuvant radiotherapy substantially reduced DFS risk. PNI was associated with decreased DFS and LRC in early-stage, low-risk OCSCC patients. In patients with PNI-positive tumors, the multivariable analysis revealed that adjuvant radiotherapy decreased DFS risk. These findings support using adjuvant radiotherapy for early-stage OCSCC patients with PNI.

Source: sciencedirect.com/science/article/abs/pii/S1368837523001161