When it comes to OVARIAN CANCER, oral birth control pills DO indeed protect against cancer. This effect is so significant that female patients with a family history of ovarian cancer (say, the patient's mom or sister or grandmother had ovarian cancer) are often put on the pill as a prophylactic measure.
Because most birth control pills contain high doses of estrogen, however, they INCREASE the risk of estrogen-responsive cancers such as BREAST CANCER.
It's also worth noting that estrogen can INCREASE THE RISK OF HPV INFECTION because of the effects it has on the squamo-columnar junction of the cervix (the area where cells can get infected with HPV). Although HPV can be naturally cleared by the body's immune system, when it persists it can over time lead to CERVICAL CANCER.
Oral contraceptives (OCs) are the most popular form of birth control in the United States. While oral contraceptive pills help prevent pregnancy, they also alter your risk of developing certain types of cancers, including ovarian and breast cancer. This is due to the presence of two hormones, estrogen and progesterone, which are key ingredients of OCs and also occur naturally in the body. The addition of estrogen and progesterone from OCs to your natural levels of these hormones can influence your chances of developing some cancers. Here is the latest data:
- Ovarian cancer: Studies have consistently shown that use of OC pills reduces the risk of ovarian cancer by 20 to 50 percent, depending on how long the OCs were taken. Even a small duration of use showed a difference, but a 50 percent reduction in ovarian cancer risk was seen in women who took oral contraceptives for 15 years. Also, this decreased risk lasts for 30 years after these women stopped taking the OCs.
- Endometrial cancer: The endometrium is the lining of the uterus, which is shed each month during menstruation. The use of OC pills decreases the risk of endometrial cancer as well. In one study, women using OC pills for at least 12 months had a 40 percent decreased risk of endometrial cancer when compared to women who never took OCs. In addition, this decreased risk lasts for at least 15 years after they stopped taking OCs.
- Breast cancer: There is no clear cut answer to this question. What I can say is that OC use does not appear to cause an increased risk of breast cancer later in life.
- Cervical cancer: The cervix is the passage from the vagina into the uterus. Studies seem to show that women who have taken OCs for more than five years have a slightly increased risk of developing cervical cancer. While the risk is increased, it is important to know that as long as you are getting regular pap smears, the risk that you will actually develop cervical cancer is very low. In fact, in women who are positive for high-risk human papillomavirus (HPV, the virus that causes cervical cancer) and who took OCs, the risk of developing cervical cancer increased from only .0038 to .0045 percent. This means that the risk is greater, but still extremely low. Also, once you stop taking OCs, the risk of cervical cancer immediately begins to decrease and in 10 years becomes the same as those who have never taken the pill.
If you are concerned about your risk for cancer please talk to your health care provider.