[A case of rectal cancer with multiple liver metastases responding to TS-1]

A 63-year-old woman was referred to our hospital with complaints of anal pain, constipation and abdominal distention caused by a rectal tumor. After examinations, she was diagnosed as rectal cancer with multiple liver metastases. The CEA level was 70.0 ng/ml and the CA19-9 level was more than 5,000 U/ml at admission. To prevent bowel obstruction, low anterior resection of the rectum was performed. At 34 days after operation, TS-1 chemotherapy was started as outpatient treatment (each course consisted of daily oral administration of 100 mg TS-1 for 4 weeks followed by 2 drug-free weeks). After the first course, the CEA level was reduced to 3.3 ng/ml and the CA19-9 level to 15 U/ml, both under the normal value. After the second course, administration was discontinued due to diarrhea, and restarted as a daily oral administration of 80 mg TS-1. After the five courses, the CEA level was 4.0 ng/ml and the CA19-9 level was 4 U/ml, both under the normal value. Multiple liver metastases had remarkably reduced in the CT findings. The patient continues to undergo outpatient treatment with good QOL.