Estrogens and Estrogenic Chemicals Increase Breast Cancer Risk
Estrogenic chemicals, including but not limited to DDT, dioxins, organochlorines and others reduce the natural body's defense against breast cancer. Environ Health Persp 115: A297, 2007
Excess estrogens can help breast cancer cells grow. New studies show that excess estrogen can increase breast cancer tumor growth. This can occur from natural estrogen, known as estradiol, synthetic estrogen, or the drug tamoxifen.
Research suggests that the drug tamoxifen could block the killing of cancer cells by the body’s immune "natural killer cells".
Women receiving estrogen should always be tested to ensure that they need estrogen, that their estrogen remains within normal physiologic range, and is balanced with physiologic levels of progesterone. Testing can only detect natural estrogens and progesterone. Progesterone helps control abnormal breast cancer cell growth.