There are two primary types of oral birth control available in the US. Both are prescriptions formulated with synthetic hormones. One type, combined oral contraceptive, contains progesterone and estrogen. The second, the mini pill, contains only progestin, a synthetic progesterone used for contraceptive purposes.
Scientists know there is a link between naturally occurring sex hormones and the growth of certain types of cancers. According to
Marla Ahlgrimm, it is suspected that since birth control pills contain these hormones, there may be a link between these cancers and contraceptive use. Interestingly, the risk of ovarian and endometrial cancer appear to be reduced in women who regularly use oral contraceptives. Adversely, the rates of liver, cervical, and breast cancer are higher in the same demographic.
Breast cancer risks
Marla Ahlgrimm explains that a woman’s risk of developing breast cancer is dependent upon numerous factors. Many of these are related to her natural hormone production. Early menstruation, late-onset menopause, advanced-age pregnancy, and not having children all increase a woman’s risk of breast cancer. In 1996, a collaborative study found that women who were recent birth-control users had a slightly elevated risk of breast cancer, says Marla Ahlgrimm.