[Secondary chronic myelogenous leukemia following postoperative TS-1 therapy for advanced gastric cancer]

A 78-year-old man received total gastrectomy for advanced gastric cancer in September 2006, and was subsequently treated with oral anti-metabolite TS-1 for 38 months. He had no evidence of recurrence of gastric cancer, although he had a continuous poor appetite due to TS-1. Leukocytosis was found in November 2008. On the basis of bone marrow findings, Philadelphia chromosome and BCR-ABL fusion gene, he was diagnosed as having chronic phase of secondary chronic myeloid leukemia (CML). Two weeks after starting imatinib therapy, skin eruption, palpebral edema and appetite loss were observed; moreover, thrombocytopenia gradually worsened. He stopped taking imatinib and hydroxyurea was subsequently started. The above symptoms disappeared and the platelet count normalized. CML is rare in secondary leukemia. Our case is the second reported case of secondary CML following TS-1 treatment and suggests that therapy for secondary CML should be selected on the basis of QOL in patients with advanced cancer.