Does the Pill cause cancer?

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Does the Pill cause cancer?

Overall cancer risk

Overall, if there is an increase in cancer risks for women taking hormonal birth control, it appears to be very small. Taking the Pill may reduce a woman's risk for most cancers. This benefit for some cancers may last as long as 15 years after a woman stops taking the Pill. However, long-term use of the Pill (more than 8 years) may slightly increase a woman's overall risk of cancer.¹

Breast cancer risk

Based on the following findings, experts say that estrogen-progestin contraception pills have little, if any, effect on breast cancer.²

Some experts say that birth control hormones DO NOT not cause breast cancer.

• Based on the largest studies of breast cancer risk, researchers state that women who have a strong family history of breast cancer can take birth control pills without further raising their breast cancer risk.³ (Some experts disagree; see below.)
• A recent study of low-dose birth control pills found no increase in breast cancer cases among current users and a lower risk of breast cancer among past users.⁴
• By the age of 55, past users of birth control pills have the same rate of breast cancer diagnosis as women who have never used birth control hormones.³

Some experts say that birth control hormones MAY cause breast cancer.

• Some experts are not yet convinced that birth control pills are completely safe for women who have a strong family history of breast cancer or for women who have the high-risk BRCA1 or BRCA2 gene mutations.⁵
• Several past studies have found a slightly higher-than-normal rate of breast cancer among current users. This may be because taking birth control hormones promotes the growth of breast cancer cells that are already present, but would not yet be multiplying on their own. On the other hand, it may be that these women were closely studied and breast cancer detection was better than in the normal population.³

Cervical cancer risk

Cervical cancer is caused by infection with a sexually transmitted human papillomavirus (HPV). The Gardasil vaccine (What is a PDF document?) , for girls or women ages 9 to 26, protects against the most common forms of genital warts that cause cervical cancer.⁶ You can lower your chance of infection by using condoms. Regular Pap tests are the most effective screening method for cervical cancer. Widespread use of the Pap test has greatly lowered rates of cervical cancer. This is because the test detects precancerous cell changes in the cervix, before actual cancer starts.

Based on current research, you may be more likely to develop cervical cancer if you use birth control pills and you are HPV-infected. You may also be more likely to become infected if you are exposed to HPV. This may be because long-term use of birth control pills makes the cells of the cervix more vulnerable.⁵

Ovarian cancer protection

Combination pills reduce the risk of ovarian cancer after 1 year of use. This benefit seems to last for years after stopping the Pill.⁷

Colon cancer and endometrial cancer protection

Taking combination birth control pills for 1 year or longer lowers the risk of colon cancer and cancer of the uterine lining (endometrial cancer). The longer you take the Pill, the lower your risk of endometrial cancer.²

References

Citations

1. Hannaford PC, et al. (2007). Cancer risk among users of oral contraceptives: Cohort data from the Royal College of General Practitioner’s oral contraception study. BMJ, 335(7621): 651–658.

2. Hatcher RA, Nelson A (2004). Combined hormonal contraceptive methods. In RA Hatcher et al., eds., Contraceptive Technology, 18th ed., pp. 391–460. New York: Ardent Media.

3. Hatcher RA, et al. (2005). Pocket Guide to Managing Contraception 2005–2007. Tiger, GA: Bridging the Gap Foundation.

4. Marchbanks PA, et al. (2002). Oral contraceptives and the risk of breast cancer. New England Journal of Medicine, 346(26): 2025–2032.

5. Petitti DB (2003). Combination estrogen-progestin oral contraceptives. New England Journal of Medicine, 349(15): 1443–1450.

6. U.S. Food and Drug Administration (2006). FDA licenses new vaccine for prevention of cervical cancer and other diseases in females caused by human papillomavirus. FDA News. Available online: http://www.fda.gov/bbs/topics/NEWS/2006/NEW01385.html.

7. Abramowicz M (2004). Choice of contraceptives. Treatment Guidelines From the Medical Letter, 2(24): 55–62.

Credits

Last updated:	May 22, 2008
Author:	Bets Davis, MFA
Reviewed By:	Joy Melnikow, MD, MPH - Family Medicine, Kirtly Jones, MD - Obstetrics and Gynecology
Editors:	Maria G. Essig, MS, ELS, Pat Truman, MATC