[Locally advanced squamous cell carcinoma of the buttocks, which had complete remission induced by chemoradiotherapy with carboplatin].

The patient was a 72-year-old male who had locally advanced squamous cell carcinoma(10×7 cm)in his buttocks that developed 18 months prior to admission. The lesion was unresectable because of the size and its invasion to the sacrum. We performed concomitant chemoradiotherapy with curative intent. External beam radiotherapy(68 Gy)was given with weekly carboplatin(AUC 2)and paclitaxel(30mg/m2). Because he developed cellulites in the irradiated skin, the concurrent chemotherapy was stopped during treatment(at 10 Gy). After improvement of the cellulites, paclitaxel was switched to S-1(80 mg/body/day)and concurrent chemoradiotherapy was completed without further toxicities. Progression of the tumor outside the irradiated field was seen 4 months after the treatment. Four courses of carboplatin (AUC 5)+infusional 5-FU(1, 000mg/m2 day 1-4)was administered as the tumor regressed. He died of sepsis 36 months post-treatment but the tumor remained stable without progression. Chemoradiotherapy may be an option for locally advanced non-melanoma skin cancer.