Despite decades of scientific scrutiny, the mechanics of how different types of estrogen interact with cancer is not well understood. Some scientists say the sex hormone protects women from getting breast cancer; others say it fuels the growth of cancer cells.
Rachel Carson, who died of breast cancer two years after publishing “Silent Spring” in 1962, considered the synthetic estrogens found in drugs and cosmetics to be possible carcinogens. In the 1970s, epidemiological studiesof…