Prognostic importance of pathological response to neoadjuvant chemotherapy followed by definitive surgery in advanced oral squamous cell carcinoma

Objective: The clinical importance of neoadjuvant chemotherapy (NAC) followed by definitive surgery was retrospectively investigated in clinical Stage III/IV oral squamous cell carcinoma (OSCC). Methods: Surgery was performed for OSCC in 164 patients, including 72 patients who had received NAC (two cycles of cisplatin and fluorouracil) prior to surgery from January 2004 to December 2014. The clinical characteristics and survival parameters of the groups that received and did not receive NAC were evaluated. The pathological response was classified as Grade 0 (no effect), 1a (very slight effect), 1b (slight effect), 2 (moderate effect) or 3 (marked effect), and its correlation with prognosis was investigated. Results: There were no statistical differences in survival indicators between patients who received NAC and those who did not (overall survival, P = 0.75). The proportion of patients who received NAC in the effective NAC group (Grades 1b, 2, and 3) was 52.8%. After a median follow-up of 35 months, overall survival (P = 0.01), disease-free survival (P = 0.002), locoregional disease-free survival (P = 0.003), and distant disease-free survival (P = 0.01) were significantly better in the effective NAC group than in the less effective NAC group (Grades 0 and 1a). Conclusion: Although NAC had a limited effect on disease prognosis in OSCC, the pathological response to NAC could be an important prognostic indicator for advanced OSCC.