Neoadjuvant radiotherapy plus radical surgery for locally advanced stage III/IV oral cancer: Analysis of prognostic factors affecting overall survival.

OBJECTIVES: Preoperative radiotherapy followed by surgery is an effective treatment option for solid tumors including locally advanced squamous cell cancers of the head and neck region. Histopathologic response to radiation has been shown to be associated with survival. However, the relative prognostic importance of regression grade compared to other potential biomarkers has not been established yet. MATERIALS AND METHODS: One-hundred forty-four oral squamous cell carcinoma patients with stage III/IV disease were included in this analysis. Patients had received preoperative radiotherapy (RT) up to 50Gy total dose in combination with 5-Fluorouracil (5-FU)/Mitomycin C (MMC) or with Cetuximab, followed by radical surgery six to eight weeks later. Outcome data were obtained from the patient's files. Survival rates were estimated by the Kaplan-Meyer method. Cox-proportional-hazard regression models were used to compare the risk of death among patients stratified according to risk factors. RESULTS: Five-year overall survival (OS) was 58% in the presented collective. Regression grade 4 (HR 3.58; p<0.001) was most significantly associated with reduced survival, followed by elevated neutrophils (HR 2.22; p=0.01), the combination of elevated neutrophils plus elevated CRP (HR 2.40; p=0.01), and elevated CRP alone (HR 1.74; p=0.03). In a multivariate analysis, the regression grade remained the most influential predictor of outcome (HR 4.23; p<0.001). CONCLUSION: In a comparative analysis, tumor response to pre-operative radiotherapy remains the strongest prognostic factor for treatment outcome, while elevated CRP, as well as neutrophils, were also found to be of significance.