[A Case of Gastric Cancer Invading the Pancreas with Pathological Complete Response Treated by Preoperative S-1 plus Oxaliplatin Therapy].

A 66-year-old man with severe anemia was diagnosed with gastric cancer. CT examination revealed primary gastric tumor, which involved the pancreas body, with regional lymph nodes that were enlarged(T4b[panc], cN2, cM0, cStage ⅣA). He received three courses of preoperative S-1 plus oxaliplatin therapy. Primary tumor and metastatic lymph nodes were reduced remarkably. We performed a curative distal gastrectomy(D2)without pancreas resection. Histopathological examination revealed Grade 3 pathological complete response in both primary tumor and metastatic lymph nodes.