There exist a crucial link between breast cancer and estrogen. Estrogen hormone plays a vital role in stimulating cell division process in breast. Its presence is very important during the critical period of breast growth and development. Estrogen hormone also affects the other hormones which are stimulating cell division process in breast.

Women who are exposed to high level of estrogen throughout the lifetime are at a greater risk of developing breast cancer. It is because of this reason that prolonged estrogen therapy must be avoided. Lifestyle and environmental factors are also responsible for change in estrogen level in the body. Studies have also shown that women who experience menarche at very early stage of life or experience menopause at very later stage are subjected to risk of developing breast cancer. The relationship between the estrogen and breast cancer was shown around 100 years ago where the women suffering from breast cancer showed improved chances of survival after the ovaries were removed.

This is because the estrogen hormone is produced in the ovary. Studies have shown that the amount of estrogen level in the body of women suffering from breast cancer was very high as compared to those not suffering from breast cancer.