[A case of local relapsed rectal cancer responding to low-dose S-1]

We report a case of local recurrent colorectal cancer that has been treated successfully with low-dose oral chemotherapeutic agent. An 80-year-old man underwent a low anterior resection for rectal cancer. Two years and nine months later, a recurrent tumor was revealed in the vicinity of the anastomotic region by colonoscopy. Additional examination by enhanced CT elucidated the tumor infiltrated the sacrum. For this reason, we planned an abdominoperineal resection of rectum with sacrum excision for treatment. However, we considered that he could not overcome the burden of operation for his complication. As a result of informed consent with the patient and his family, we decided a conservative treatment, and started chemotherapy using S-1. The tumor has been diminished slowly on enhanced CT and colonoscopy. The chemotherapy using S-1 has been continued with good quality of life for over five years. S-1 is expected to be an effective choice for the patient of colorectal cancer who cannot be taken the standard treatment for various reasons.