Four cases of therapy-related leukemia

Combination chemotherapy and radiation therapy have contributed to the succ essful treatment of various cancer patients. But the development of second malignancies is an inevitable complication of long-term cytotoxic treatment . The most serious and frequent of such complications is acute myelogenous leukemia (AML). Therapy-related leukemia is generally fatal. Since the numb er of patients exposed to chemotherapy is increasing each year, the clinica l significance of this entity cannot be underestimated. There have been man y investigations of therapy-related leukemia, but in Korea published report s are rare. We describe four such cases, involving one older female with lu ng cancer and three children with acute lymphoblastic leukemia (ALL) and ma lignant lymphoma. Alkylating agents were used for chemotherapy, and in one case, topoisomerase II inhibitor. Irrespective of the causative agents, the latency periods were relatively short, and despite induction chemotherapy in two, all survived for only a few months. During the follow-up of patient s treated for primary malignancies, the possibility of therapy-related leuk emia should always be borne in mind.