Histological complete response in a case of advanced gastric cancer treated by neo-adjuvant chemotherapy with S-1/CDDP

A 59-year-old male was found to have advanced gastric cancer with multiple lymph node metastasis including para-aortic lymph nodes (cT3, cN3, cM0, cH0, cP0, cStage IV). Since curative surgery was deemed not feasible, we tried neoadjuvant chemotherapy expecting downstaging of the tumor. S-1 (120 mg/body) was orally administered for three weeks followed by one week rest, and CDDP (60 mg/m²) was administered on day 8. Three courses of treatment resulted in a marked shrink-age of the primary lesion and a reduction of lymph nodes. He was judged as clinical PR by RECIST, and a radical resection was considered possible. Laparotomy revealed neither ascites nor peritoneal dissemination, and he underwent total gastrectomy, splenectomy and D2+para-aortic lymph node dissection with curative intent. The histological diagnosis revealed complete disappearance of cancer cells in the primary lesion of the stomach and lymph nodes, confirming a pathological complete response. The patient has been alive for six months without recurrence.