[A Case of BRAF-Mutated Obstructive Colon Cancer with Liver Metastases Treated with Multidisciplinary Therapy]

A 39-year-old woman visited our hospital with complaints of nausea, vomiting, and lower abdominal pain for 2 weeks. Abdominal CT revealed thickening of the transverse colonic wall, dilated bowel, and a metastatic ischemic tumor in the liver (S7). We diagnosed her with obstructive colon cancer, clinical Stage Ⅳa(T, type 2, cT3, N0, M1a[liver]). At first, we placed a self-expanding metallic stent(SEMS)to decompress bowel obstructions. We planned a surgical resection of the primary tumor followed by partial resection of the liver. We performed a laparoscopic right hemicolectomy(D3)24 days after the stenting. Pathologically, we diagnosed her with BRAF-mutated colon cancer, pStage Ⅳa(pT4a, N1b[2/43], M1a[liver]). On completion of 4 courses of mFOLFOXIRI and bevacizumab, we confirmed a reduction of the S7 tumor but found a new tumor in S6. Since the tumors were potentially resectable, we performed partial liver resection(S6, S7)1 month later. A month following the hepatectomy, CT revealed a new tumor in S4. The patient has been receiving general chemotherapy (CapeOX and bevacizumab)without disease progression for 6 months. We experienced a challenging case of BRAF- mutated obstructive colon cancer with liver metastases.