Decreasing risk of leukemia with prolonged follow-up after chemotherapy and radiotherapy for Hodgkin's disease.

Acute nonlymphocytic leukemia is a recognized complication of combined chemotherapy and radiation treatment of patients with Hodgkin's disease. Previous studies have suggested that the risk of leukemia in these patients increases with time after treatment. We analyzed the occurrence of second neoplasms among 192 patients with Hodgkin's disease who were followed for a median of over 15 years. We originally planned to identify prospectively the morphologic changes in bone marrow that precede the development of acute leukemia. All 63 patients consenting to bone marrow aspiration had normal marrow morphology, and no case of acute leukemia occurred more than 11 years after treatment. Actuarial analysis revealed that the peak onset of leukemia-related complications was between three and nine years after first treatment. We conclude that there appears to be a period of increased risk in patients treated with chemotherapy and radiation, after which the risk of secondary leukemia decreases. Patients surviving for more than 11 years after treatment appear to be at no increased risk of acute leukemia.