Chromosomal Translocations in Secondary Acute Myeloid Leukemia

To the Editor: Acute myeloid leukemia (AML) occurs in up to 15 percent of patients treated with cytotoxic drugs, radiation, or both.1 In the leukemic cells of these patients, losses of chromosome 5, 7, or both are most common; a balanced translocation involving chromosome band 11q23 and the MLL gene is closely associated with prior treatment with drugs that inhibit topoisomerase II.2–6 The Clinical Investigations Branch of the National Cancer Institute has compiled eight cases of chemotherapy-related AML among the 2548 patients with node-positive breast cancer who were enrolled in Protocol B25 of the National Surgical Adjuvant Breast and . . .