Incidence of malignant fallopian tube tumors.

Incidence rates were examined for epithelial malignant fallopian tube neoplasms diagnosed between 1973 and 1984 and reported to nine population-based cancer registries in the United States. The average annual incidence was 3.6 per million women per year and there was no evidence of a change in the rate during the study period. Age-specific incidence followed a pattern similar to that observed for ovarian and endometrial neoplasms, rising rapidly during the reproductive years and flattening out thereafter. The incidence rate varied only slightly by race, with whites having a higher rate than blacks. Considerable variation in incidence was observed among the registries. While this could have been due to true regional differences in incidence, we cannot rule out the possibility that misclassification of fallopian tube tumors as ovarian tumors was responsible. Further investigations into the etiology of fallopian tube neoplasms should focus on the role of reproductive factors that have previously been reported as risk factors for ovarian and endometrial neoplasms.