Acute nonlymphocytic leukemia in patients receiving chemotherapy for nonmalignant diseases

The occurrence of acute leukemia in patients receiving chemotherapeutic agents for malignant disease has been well established. Recent reports have suggested that chemotherapeutic drugs used to treat inflammatory conditions may have an oncogenic potential. From 1969 to 1977, 11 patients with a variety of collagen-vascular diseases who developed acute nonlymphocytic leukemia were seen at the Cleveland Clinic. Rheumatoid arthritis was the most common underlying disease, in addition to giant cell arteritis, polyarteritis nodosa, chronic glomerulonephritis, and scleroderma. All patients were treated with alkylating agents, and 10 of the 11 received multiple cytotoxic agents. According to the French-American-British classification there were six examples of M4 (myelomonocytic leukemia), with single examples of M1 (myeloblastic leukemia without maturation), M2 (myeloblastic leukemia with maturation), M5a (monocytic leukemia, poorly differentiated), M5b (monocytic leukemia, differentiated), and M6 (erythroleukemia). Cytogenetic studies were abnormal in five patients studied, showing varying degrees of aneuploidy. All patients died, and the mean duration of time from the diagnosis of leukemia to death was four and one-half months, with only one complete remission.