[A case of CA19-9 producing gastric cancer treated by low-dose administration of TS-1 for adjuvant chemotherapy].

A 72-year-old woman underwent total gastrectomy for CA19-9 producing gastric cancer. TS-1 was administered for recurrent gastric cancer because the duodenal stump was histologically positive and the serum CA19-9 level elevated after temporary regression. The dose was reduced from 80 mg/body/day to 50 mg/body/day because of grade 3 neutropenia.