Evaluating the effectiveness of adjuvant radiotherapy in addition to surgery versus surgery alone at improving oncologic outcomes for early stage buccal carcinoma: a systematic review

OBJECTIVE: To systematically review the evidence to evaluate oncologic outcomes for patients with early stage buccal squamous cell carcinoma treated with surgery versus surgery and adjuvant radiation therapy. DATA SOURCES: Ovid MedLine, EMBASE, Google Scholar, PubMed. REVIEW METHODS: The primary purpose was to perform a systematic review to determine the published literature comparing oncologic outcomes of patients with early stage (Stages I&II) buccal mucosal squamous cell carcinoma, treated with surgical resection alone versus surgery plus adjuvant radiation therapy. Oncologic outcomes of interest were overall survival, locoregional recurrence, and disease specific survival. The secondary aim was to perform a meta-analysis to quantitively compare and summarize the data on oncologic outcomes between treatments. RESULTS: A total of 1457 studies were screened and five retrospective cohort studies (n = 733 patients) were eligible for quantitative analysis. Overall study quality was moderate to high. Pooled relative risk ratios using a fixed effects model did not reveal any statistically significant difference in overall survival (p = 0.70) or locoregional recurrence rates (p = 0.72) in Stage I and II disease. CONCLUSIONS: These results demonstrate there is sparse evidence comparing oncologic outcomes for early stage buccal squamous cell carcinoma treated with surgery alone versus surgery and adjuvant radiation therapy. Our findings based on a limited body of evidence suggest no obvious benefit in the addition of adjuvant radiation therapy, however robust randomized trials are warranted to reach firm conclusions.