Risk of exogenous estrogen therapy and endometrial cancer

Abstract

A retrospective study was carried out on 431 patients with endometrial cancer and 431 control subjects matched as to age, race, and parity. They were seen at Duke University Medical Center from 1940 to 1975. The study was performed in order to evaluate the risk of exogenous estrogen therapy and the development of adenocarcinoma of the endometrium. The overall risk was 2.38, with certain subgroups demonstrating different degrees of risk. Increased risk was associated with estrogen therapy of longer than 5 years' duration in white patients. The risk also was confined to Stage I, grade 1 lesions and more superficial myometrial invasion. Five-year survival for patients who used estrogen replacement and had Stage I, grade 1 lesions was 94.7%. The risks associated with exogenous estrogens are real but should be considered in a risk/benefit context when prescribing for the needs of an individual patient.

PIP: 431 endometrial cancer patients and 431 age-, race-, and parity-matched controls were studied retrospectively to assess the risk of endometrial adenocarcinoma (excluding Stage 0) associated with exogenous estrogen therapy; risk evaluations are presented. The study was concerned with patients at the Duke University Medical Center from 1940-1975. Overall, the risk of endometrial cancer associated with exogenous estrogen use was 2.38; subgroups demonstrated differing degrees of risk, e.g., use-duration, race, and invasiveness. Increased risk was associated with duration of greater than 5 years and with whites. Risk was also confined to Stage 1, Grade 1 myometrial superficial invasive changes. It was determined that the 5-year survival for patients who used estrogen replacement and had Stage 1, Grade 1 lesions was 94.7%; hence, the authors advocate careful attention to the risk-benefit notion in this therapy, given the high incidence of survival, the minimal risk of severe disease, and the beneficial effects of estrogen replacement.