The epidemiology of sarcomas of the uterus.

Data from nine population-based cancer registries (1973-81) were analyzed to examine the demographic characteristics that are related to the occurrence of sarcomas of the uterus. Leiomyosarcoma and mixed mesodermal sarcoma accounted for 86% of 1,452 uterine sarcomas reported, and both were more common in black women than in white women. The incidence of mixed mesodermal sarcoma was low through middle age, after which it rose sharply. The incidence of uterine leiomyosarcoma, however, was highest in middle-aged women and declined thereafter. The age-incidence pattern of uterine leiomyosarcoma resembles that of carcinomas of the female reproductive tract, unlike the pattern of other uterine sarcomas or sarcomas occurring elsewhere. This suggests that one or more factors that play a role in the etiology of carcinomas of the reproductive tract may be involved in the etiology of this tumor as well.