In theory, the use of estrogen-based oral contraceptives increases a womanís exposure to estrogen, and thus increases her risk of breast cancer.
However, current studies show no significant increase of cancer related to the use of low-dose oral contraceptives, even in women who take them for extended periods of times. On the other hand, higher-dosed oral contraceptives have been associated with higher breast cancer risk.
Because most of the birth control pills on the market today contain very low doses of estrogen, the likelihood that the medication will increase your risk is small. Nevertheless, it is always a good idea to talk to your doctor about the different birth control choices, especially in regards to their comparative levels of estrogen.