A case of advanced colon cancer with metastases to both para-aortic lymph nodes and cervical vertebrae effectively treated by TS-1 therapy

The patient was a 68-year-old woman who had cecal cancer with para-aortic lymph node metastases. Ileocecal resection was performed palliatively. Since metastasis to cervical vertebrae was detected after the operation, she received radiation therapy of 14 Gy to improve neck pain. Chemotherapy with TS-1 (80 mg/day) was started on an outpatient basis (4 weeks administration followed by a 2-week drug-free period). After 4 courses of this chemotherapy, metastases to both para-aortic lymph nodes and cervical vertebrae were remarkably reduced on CT and PET. Throughout the period of treatment, there was no adverse effect and this treatment has been maintained. In conclusion, this case seems significant from the viewpoint of achieving a partial response to TS-1 and maintaining a high quality of life. Moreover,we identified the presence of TS and DPD using an immunohistochemical staining technique. The primary tumor was positive for DPD stain test and negative for TS stain test. It was suggested that this cancer especially would respond to TS-1 chemotherapy.