Relationship of Leukemia Risk to Radiation Dose Following Cancer of the Uterine Corpus

Background: Radiotherapy has been linked infrequently to secondary leukemia despite extensive exposure of the active bone marrow to ionizing radiation. Few studies include sub-stantial numbers of elderly patients. Purpose: We evaluated women with cancer of the uterine corpus, the majority of whom were treated at older ages, to gain additional informa-tion on cancer risk following partial-body radiotherapy and to examine differences in risk between external-beam therapy and brachytherapy. Methods: A cohort of 110 000 women with invasive cancer of the uterine corpus who sur-vived at least 1 year following their initial cancer was as-sembled from nine population-based cancer registries. Cancer diagnoses occurred from 1935 through 1985, and most patients were diagnosed during the 1960s and 1970s. Radiation doses were computed to 17 sections of the activ