[Two cases of advanced gastric cancer completely responding to S-1 neoadjuvant chemotherapy]

CASE 1: A 67-year-old man had advanced gastric cancer with lymph node metastasis (cT3N1M0, cStage IIIA). S-1 120 mg was administered for 21 days as neoadjuvant chemotherapy (NAC). A month later, total gastrectomy (with splenectomy) was performed. Histopathological examination revealed no cancer cells in the gastric wall and dissected lymph nodes. CASE 2: A 62-year-old man had advanced gastric cancer with lymph node metastasis (cT4aN2M0, cStage IIIB). He was treated with daily oral administration of S-1 120 mg (28-day administration followed by 7-day rest, and then 14- day administration) as NAC. A month later, total gastrectomy was performed. Histopathological examination revealed no cancer cells in the gastric wall and dissected lymph nodes. In both cases, the pathological effect was judged as grade 3. This suggests that NAC with S-1 mono-therapy can have a distinct therapeutic value for advanced gastric cancer.