INTRODUCTION
colorectal cancers, Squamous cell carcinoma of the anal
RARE DISEASE, COLORECTAL CANCERS
Squamous cell carcinoma of the anal canal (SCCAC) is a rare disease. SCCAC-related morbidity accounts for 4% of colorectal cancers in the USA, and this number has tripled in the last 30 years [The standard treatment for localized SCCAC remains chemoradiotherapy with 5-fluorouracil (5-FU) and mitomycin-C (MMC), based on the results of several clinical trials in Europe and the USA [Therefore, this study aimed to evaluate the efficacy and safety of chemoradiotherapy with reduced dose of 5-FU and MMC in Japanese patients with localized SCCACs.