Clinical and histopathologic effects of neoadjuvant intra-arterial chemoradiotherapy with cisplatin in combination with oral S-1 on stage III and IV oral cancer.

Objective: The aim of this study was to examine the clinical and histopathologic effects of neoadjuvant intra-arterial chemoradiotherapy (IACRT) using cisplatin in combination with oral S-1 (tegafur/gimeracil/oteracil potassium) on stage III and IV oral squamous cell carcinoma.

Study Design: Thirty patients received infusions of superselective intra-arterial cisplatin 60 mg/m by the Seldinger method and conventional external beam radiotherapy (total 40 Gy) combined with oral S-1 on the day of irradiation. Curative surgery and neck dissection were performed 4 to 6 weeks after IACRT. The clinical response of the primary lesion was evaluated approximately 4 weeks after IACRT. The surgically resected specimens were examined for histologic features according to the grading system for histologic evaluation and for residual tumor grade (RGrades).

Results: Histopathologic evaluation of the therapeutic effect was grade 2 in 10 patients and grade 3 in 16 patients. According to the distribution of RGrades, the remaining tumor cells were mostly in the central area of the primary lesion, as seen in 24 patients.

Conclusions: These findings indicate that neoadjuvant IACRT with cisplatin and oral S-1 was an effective treatment, suggesting the possibility of reducing the extent of curative surgery based on RGrades.