How Hormones Affect Breast CancerFact Sheet
Studies show that current or recent use of birth control pills (oral contraceptives) slightly increases the risk of breast cancer [11,31-34].
A pooled analysis of data from more than 50 studies found that while women were taking birth control pills (and shortly thereafter), they had a 10 to 30 percent higher risk of breast cancer than women who had never used the pill . Once women stopped taking the pill, their risk began to decrease and after about 10 years, returned to that of women who have never taken the pill .
In most studies on this topic, women were taking older, higher-dose forms of the pill.
Although taking the pill slightly increases risk, most women on the pill have a low risk of breast cancer because they are young and premenopausal. So, even with a slight increase in risk, they are still unlikely to get breast cancer. And, once women stop taking the pill, the slight increase in risk begins to decrease and over time, goes away .
Before making any decisions about birth control pills, you should talk to your health care provider and weigh the pros and cons of using them. Though they have some risks, birth control pills can prevent unwanted pregnancies and decrease the risk of both uterine and ovarian cancers [35-37].
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”). At this time, there are too few data to comment on whether these pills affect breast cancer risk the same as other types of birth control pills.
For a summary of research studies on birth control pills and breast cancer, visit the Breast Cancer Research section.
Like birth control pills, Depo Provera (an injected contraceptive), the birth control patch and the vaginal ring contain hormones. Depo Provera contains 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 [38-41].
A pooled analysis and a study on Depo Provera showed no impact on breast cancer risk overall. However, a possible increase in risk was found among current, longer-term users compared to women who never used Depo Provera [40-41].
Talk to your health care provider about the pros and cons of Depo Provera or other types of birth control containing hormones before using them.
Blood Androgen Levels