[A patient with sigmoid colon cancer( cStage IV) who responded to preoperative chemotherapy with mFOLFOX6 plus bevacizumab and was subsequently able to undergo a radical operation].

There are a growing number of reports of unresectable, advanced colorectal cancer and multiorgan invasive colorectal cancer for which extended surgery was avoided or a radical operation was performed after down-staging, or tumor size reduction, was achieved by chemotherapy. Here we describe a case of sigmoid colon cancer (cStage IV) for which preoperative chemotherapy improved the outcome of surgery. The patient was a 57-year-old man with sigmoid colon cancer of sufficient size to block the passage of the endoscope. The cancer was found to be widely infiltrated and adherent to the peritoneum over the bladder, with effusion around the tumor that made peritoneal disseminated metastasis a strong possibility. Moreover, many regional and periaortic lymph nodes were swollen. Sigmoid colon cancer at Stage IV was diagnosed. After preoperative chemotherapy [mFOLFOX6+bevacizumab (Bev)] was administered, tumor size decreased sufficiently to allow the endoscope to pass through. The effusion around the tumor disappeared, and lymph node swellings were reduced. The surgical findings revealed no evidence of peritoneal metastasis, and tumor adhesion to the peritoneum over the bladder was small, which limited the extent of combined peritonectomy. Ultimately, the histopathological diagnosis was Stage II,and histological evaluation of the drug therapy effects was that the tumor was then Grade 1b. Although clinical studies are currently conducted on preoperative chemotherapy for locally advanced colorectal cancer, preoperative chemotherapy is not established as standard treatment due to lack of clear evidence. The evaluation of the usefulness of preoperative chemotherapy is warrants future clinical studies.