Induced acute non-lymphocytic leukemia following long-term chemotherapy: a study of 20 cases

Twenty individuals developed acute non-lymphocytic leukemia (ANLL) following long-term chemotherapy for other disorders. The primary disorders included non-Hodgkin's lymphoma (five), Hodgkin's disease (five), carcinoma (four), multiple myeloma (three), chronic leukemia (two), and rheumatoid arthritis. Leukemia developed from 11-132 months (mean approximately 60 months) following institution of chemotherapy and all cases have occurred since 1974. Pre-leukemic cytopenias were present in 15 individuals. Fifteen of the 20 patients had chromosome analyses and 14 were abnormal. The leukemia was invariably refractory to chemotherapy with a median survival of only two months. Of the patients autopsied, only one individual had any evidence of the primary malignancy. This study illustrates the need for surveillance for secondary ANLL following long-term chemotherapy with/without radiotherapy. Duration of optimal chemotherapy for the primary disease must be determined by control trials and weighed against the risk of developing a secondary leukemia.