[A case of advanced sigmoid colon cancer with peritoneal dissemination responding to FOLFOX4 therapy].

A 62-year-old woman complained of thin feces, lower blood and abdominal pain, and she was diagnosed as having bowel obstruction due to sigmoid colon cancer. Abdominal CT showed peritoneal dissemination and ascites on the surface of liver. The serum CEA levels were 663.7 ng/mL. We established a diagnosis of unresectable sigmoid colon cancer accompanied by severe peritoneal dissemination and therefore performed only transverse colostomy in April, 2006. Pathological examination of omental dissemination demonstrated moderately-differentiated adenocarcinoma. FOLFOX4 therapy was started on April, 2006. Primary lesion decrease and release from bowel obstruction after 4 cycles was judged as a partial response. The partial response continued, and the serum CEA decreased 18.5 ng/mL after completion of 16 cycles, but grade 3 neuropathy occurred. We started S-1 as second-line chemotherapy in May, 2007. There was primary lesion re-growth after 4 cycles, so we changed to S-1+CPT-11 therapy. The adverse events were grade 3 neuropathy and leucopenia throughout the course. Chemotherapy is now continued on an outpatient basis, 24 months after the medical treatment started. FOLFOX4 therapy is useful for patients with advanced colon cancer accompanied by peritoneal dissemination.