In 1985, National Breast Cancer Awareness Month (October) was created by the American Cancer Society. Funding was provided by Zeneca (later AstraZenca) , a British pharmaceutical company. AstraZenca is still (as at 2018) associated with Breast Cancer Awareness Month. AstraZenca produces Tamoxifen. Tamoxifen is an estrogen antagonist or anti-estrogen drug which works by blocking the effects of estrogen.
Pink Day is one day in October which is designated to create awareness of breast cancer and to raise money for research.
Lifetime exposure to estrogen is 2.5-3 times higher in Western women than rural Chinese women in the 1980s. China women reach menarche later, menopause earlier and have reduced levels of estrogen, progesterone and testosterone during their reproductive years.