Association of cancer of the breast and acute myelocytic leukemia

Four women are reported in whom carcinoma of the breast was diagnosed 1 to 11 months prior to the development of acute myelocytic leukemia. They were observed in a total population of 46 women with acute myelocytic leukemia seen between 1954 and 1964 in upper New York State. The coincidence was found about 30 times more frequently than would have been expected on the basis of individual occurrence rates applicable to the general population. The brief latency in these four patients who received no radiotherapy is in sharp contrast to the longer latency in a fifth patient who received radiotherapy and in 17 of 21 similar patients cited in the literature or observed in other clinics who received radiotherapy. The authors suggest that the brief latency of appearance of acute myelocytic leukemia in nonirradiated patients with cancer of the breast is consistent with the possibility of a common oncogenic stimulus.