How Hormones Affect Breast CancerFact Sheet
Current or recent use of birth control pills (oral contraceptives) slightly increases the risk of breast cancer [11,37-39].
Studies show that while women are taking birth control pills (and shortly thereafter), they have a 20 to 30 percent higher risk of breast cancer than women who have never used the pill [37,39]. This extra risk, though, is quite small because the risk of breast cancer for most young women is low [37,39]. So, even with a slight increase in risk, they are still unlikely to get breast cancer.
Once women stop taking the pill, their risk begins to decrease and after about 10 years, returns to that of women who have never taken the pill .
In most studies to date, women were taking older, higher-dose forms of the pill.
For a summary of research studies on birth control pills and breast cancer, visit the Breast Cancer Research Studies section.
Before making any decisions about using birth control pills (or if you are currently taking them and haven’t done so already), talk with your health care provider about their benefits and risks. Birth control pills have some risks. However, along with preventing unwanted pregnancies, they decrease the risk of both uterine and ovarian cancers [40-42].
Read our perspective on birth control pills and breast cancer risk (April 2013).*
One area still under study is how today's lower-dose pills affect breast cancer risk.
Some types of newer birth control pills lower the number of periods a woman has during a year. Others contain progestin, but no estrogen (often called “mini-pills”). The impact on breast cancer risk appears to vary by type of lower-dose birth control pill . Mini-pills may not increase risk at all . Early findings show that other types of lower-dose birth control pills may increase breast cancer risk, but less so than the higher-dose pills of the past . These topics are still under study.
Before using any type of birth control pills (or if you are currently taking them and haven’t done so already), talk with your health care provider about their benefits and risks.
Like birth control pills, Depo Provera (an injected contraceptive), hormone-releasing IUDs (intrauterine devices), the birth control patch and the vaginal ring contain (or release) hormones. Depo Provera and hormone-releasing IUDs contain progestin alone, while the birth control patch and the vaginal ring contain both estrogen and progestin. At this time, data on the potential link between these products and breast cancer risk are limited [43-47].
Findings on Depo Provera have shown no impact on breast cancer risk overall. However, a possible increase in risk has been found among current, longer-term users compared to women who never used Depo Provera [46-47].
Before using Depo Provera or another type of birth control with hormones (or if you are currently using one and haven’t done so already), talk with your health care provider about its benefits and risks.
Blood Androgen Levels