A Case of Simultaneous Borderline Resectable Pancreatic Cancer and Rectal Cancer-Successful Neoadjuvant Chemotherapy Leading to Curative Resection

We report a patient achieving curative resection of synchronous pancreatic and rectal cancers with neoadjuvant chemotherapy. A 71-year-old man was diagnosed with pancreatic head cancer and rectal cancer on close examination for epigastralgia. Abdominal computed tomography showed the pancreatic head cancer had semi-peri-circumferential abnormal invasion into the superior mesenteric vein(SMV), so we diagnosed the tumor as borderline resectable(BR)pancreatic cancer. Colonoscopy revealed a type 1 tumor in the rectum, and biopsy detected a well-differentiated adenocarcinoma. We administered mFOLFIRINOX as preoperative chemotherapy for BR pancreatic cancer, but there was no effect. After the change to GnP, the tumor was reduced and the extent of SMV involvement was also reduced, so pancreaticoduodenectomy(PD)was performed. There was no portal vein invasion of the tumor and R0 resection was achieved. Two months after PD, laparoscopic low anterior resection was performed for rectal cancer. The patient's postoperative course was uneventful, and he had no recurrence in 8 months.