Postoperative Radiotherapy for Oral Squamous Cell Carcinoma With Histologic Risk Factors: Are We Over-Treating?

PURPOSE

The role of postoperative radiotherapy (PORT) remains controversial for patients with low-risk oral squamous cell carcinoma (OSCC) and adverse histologic features. The aim of this study was to examine the survival benefits in the role of PORT, when compared with surgery alone, among these patients.

MATERIALS AND METHODS

In this systematic review, relevant published literature was identified in the PubMed database and eligible studies were included. Predictor variables were perineural invasion (PNI), lymphovascular invasion, and unfavorable grade. The primary outcomes were patient survival and recurrence rates. Because of the heterogeneity and insufficiency of the reported data, quantitative meta-analysis was precluded. Qualitative analysis and pooled analysis on overall survival were performed for study patients.

RESULTS

Six eligible studies were included, with a median study period of 10 years. All studies evaluated the role of PORT in pN0 OSCC patients with PNI, and 3 studies evaluated the role of PORT in patients with PNI in isolation. Overall, study patients had similar treatment outcomes between the PORT and non-PORT groups. In the pooled analysis of 325 patients, PORT was not associated with an improved overall survival rate compared with surgery alone (70.3% vs 80.2%, P = .059).

CONCLUSIONS

No evidence was found to support the application of PORT given the indication of histologic risk factors alone. The prescription of PORT for PNI, lymphovascular invasion, and unfavorable grading among otherwise low-risk OSCC needs to be approached with caution to avoid the unnecessary harm of radiation exposure.