Hadley Kirkman

Synthetic Estrogens and Liver Cancer: Risk Analysis of Animal and Human Data

In 1971, Baum et al. (1) reported a causal relationship between estrogen exposure and hepatic tumors in women. At that time, there was little or no evidence available indicating that liver tumors could be induced following prolonged estrogen treatment in experimental animals, even at high doses (2–5). Nevertheless, over the years, epidemiologic evidence continued to accumulate that supported this initial causal association in humans following the therapeutic use of estrogens in the liver (6–13). The present report summarizes the human data, largely in women, regarding the association of liver tumor incidences and estrogen intake. In addition, we present heretofore unpublished observations concerning liver tumor incidences in male and female hamsters exposed to various natural and synthetic estrogens in the absence of any other intervening agent.