[Severe bone marrow suppression during adjuvant chemotherapy for gastric cancer by S-1 and its possible relationship to dihydropyrimidine dehydrogenase deficiency].

The patient was a 70-year-old woman, who had undergone total gastrectomy and splenectomy with D2 lymph node dissection, for stage II gastric cancer. We admitted S-1 of 80 mg/day in adjuvant chemotherapy on postoperative day 28. There were no adverse events for one week, and she was discharged. Severe diarrhea occurred 6 days following discharge, but she continued to take S-1. Two weeks after discharge, she visited our hospital, suffering from severe dehydration (grade 4), leucopenia (grade 4)and thrombocytopenia (grade 3). Unfortunately, she died of lung edema and multiple organ failure 28 days after chemotherapy. We measured the mRNA expression level of dihydropyrimidine dehydrogenase (DPD) of the patient's liver by the Dannenberg Tumor Profile method. The expression level of DPD was significantly low, so we suggested that the severe bone marrow suppression might have been caused by the disordered metabolism of 5-FU.