[Adjuvant Surgery for Initially Unresectable Locally Advanced Pancreatic Cancer following Gemcitabine and S-1 Chemotherapy--A Case Report].

A man in his 60s was admitted with obstructive jaundice. A hypovascular tumor, 55 mm in diameter, was detected in the pancreas head on imaging. The superior mesenteric vein showed severe stenosis bilaterally and the roots of all branches were invaded by the tumor. The tumor was diagnosed as unresectable pancreatic cancer, and chemotherapy of gemcitabine and S-1 was administered, resulting in a remarkable reduction of the tumor size. Following 7 courses of chemotherapy, a subtotal stomach-preserving pancreatoduodenectomy was carried out. Microscopic examination revealed no residual cancer cells in the resected specimen, indicating that pathological complete remission was obtained. Although some reports suggest that surgical treatment for patients with initially unresectable pancreas cancer who show excellent response to chemotherapy may improve the prognosis, further studies are needed.