Research table: Birth control pills and breast cancer risk

This summary table contains detailed information about research studies. Summary tables are a useful way to look at the science behind many breast cancer guidelines and recommendations. However, to get the most out of the tables, it’s important to understand some key concepts. Learn how to read a research table.

Introduction: Women who currently use (or have recently used) birth control pills have a slightly increased risk of breast cancer.

A pooled analysis of over 50 studies found a small increase in breast cancer risk for 10 or more years among women who were currently taking the pill or had recently used it [1].

However, when women stop taking the pill, their risk of breast cancer starts to decline [2]. After about 5 years, their risk of breast cancer is similar to risk for women who never took the pill [2].

Although most studies have looked at older, higher dose forms of the pill, today’s lower-dose pills also appear to increase breast cancer risk [3].

Learn more about birth control pills and breast cancer risk.

Learn about the strengths and weaknesses of different types of studies.

See how this risk factor compares with other risk factors for breast cancer.

Study selection criteria: Prospective cohort studies with at least 500 breast cancer cases, pooled analyses and meta-analyses.

Table note: Relative risk above 1 indicates increased risk. Relative risk below 1 indicates decreased risk.

Study	Study Population (number of participants)	Follow-up (years)	Birth Control Pill Use		Relative Risk of Breast Cancer in Women who Used the Pill Compared to Women who Never Used the Pill, RR (95% CI)
			Current, Recent or Past Use	Duration of Use
Prospective cohort studies
Danish Sex Hormone Register Study [3]	1,797,932 (11,517 cases)	11	Current or recent use	Any length of time	1.19 (1.13-1.26)
			Past use*	Any length of time	1.00 (0.93-1.06)
NIH-AARP Diet and Health Study [4]	196,513 (11,114 cases)	15	Current, recent or past use	10 or more years	1.04 (0.97-1.11)
Nurses’ Health Study [5]	114,880 (3,383 cases)	6	Current use	Any length of time	1.20 (1.00-1.44)
			Recent or past use	10 or more years	1.11 (0.94-1.32)
Royal College of General Practitioners’ Oral Contraception Study [6]	46,022 (2,071 cases)	up to 44	Current use	Less than 5 years	1.48 (1.10-1.97)
			Past use†	Any length of time	1.12 (0.91-1.39)
Canadian National Breast Screening Study [7]	27,318 (1,707 cases)	16	Current, recent or past use	7 or more years	0.74 (0.55-0.99)‡
E3N cohort – France [8]	68,670 (1,405 cases)	6	Past use	10 or more years	0.87 (0.72-1.06)
Nurses’ Health Study II [9]	116,608 (1,344 cases)	11	Current use	8 or more years	1.42 (1.05-1.94)
Norwegian Women and Cancer Cohort [10-11]	74,862 (1,245 cases)§	8	Current use	Any length of time	1.36 (1.09-1.71)
	86,948 (1,130 cases)	4-10||	Current or past use	10 or more years	1.29 (1.05-1.60)
Norwegian-Swedish Women’s Lifestyle and Health Cohort Study [12]	103,027 (1,008 cases)	7-8||	Current or recent use	Any length of time	1.6 (1.2-2.1)
Vessey et al. [13]	17,032 (844 cases)	30-36	Current, recent or past use	8 or more years	1.0 (0.8-1.2)
Malmö Diet and Cancer Cohort [14]	17,035 (747 cases)	13	Current, recent or past use	Any length of time	1.09 (0.93-1.28)
Risch et al. [15]	33,003 (742 cases)	14	Past use¶	Any length of time	1.37 (1.06-1.78)
Icelandic Cancer Detection Clinic cohort [16]	16,928 (654 cases)	8	Current, recent or past use	Any length of time	1.32 (1.02-1.70)
Shanghai Women’s Health Study [17]	66,661 (558 cases)	8	Current, recent or past use	2 or more years	0.93 (0.68-1.25)
Pooled and meta-analyses
CGHFBC [1]**	153,536 (53,297 cases)		Current use	10 or more years	1.29 (1.18-1.41)
			Recent use††	10 or more years	1.14 (1.04-1.25)
			Past use‡‡	10 or more years	1.01 (0.96-1.05)
Gierisch et al. [18]**	44 studies		Current, recent or past use	Any length of time	1.08 (1.00-1.17)
	14 studies		Current, recent or past use	More than 10 years	1.04 (0.93-1.17)
	11 studies		Current or recent use	Any length of time	1.21 (1.04-1.41)
Nelson et al. [19]**	12 studies		Current use	Any length of time	1.30 (1.13-1.49)

* Past use was defined as one year to less than 5 years ago. Results also showed no increase in risk when past use was defined as less than one year, 5-10 years and more than 10 years.

† Past use was defined as 5-15 years ago.

‡ All women had a family history of breast cancer.

§ All women were premenopausal.

|| Follow-up time was estimated from the start and end dates of the study.

¶ Past use was defined as more than 4 years ago.

** Includes data from prospective cohort studies and case-control studies.

†† Past use was defined as 1-4 years ago.

‡‡ Past use was defined as 10-14 years ago.

References

1. Collaborative Group on Hormonal Factors in Breast Cancer. Breast cancer and hormonal contraceptives: Collaborative reanalysis of individual data on 53,297 women with breast cancer and 100,239 women with breast cancer from 54 epidemiological studies. Lancet. 347(9017):1713-1727, 1996. 
2. Burchardt NA, Eliassen AH, Shafrir AL, et al. Oral contraceptive use by formulation and breast cancer risk by subtype in the Nurses’ Health Study II: a prospective cohort study. Am J Obstet Gynecol. 226(6):821.e1-821.e26, 2022.
3. Mørch LS, Skovlund CW, Hannaford PC, Iversen L, Fielding S, Lidegaard Ø. Contemporary hormonal contraception and the risk of breast cancer. N Engl J Med. 377(23):2228-2239, 2017.
4. Michels KA, Pfeiffer RM, Brinton LA, Trabert B. Modification of the associations between duration of oral contraceptive use and ovarian, endometrial, breast, and colorectal cancers. JAMA Oncol. 4(4):516-521, 2018.
5. Hankinson SE, Colditz GA, Manson JE, et al. A prospective study of oral contraceptive use and risk of breast cancer. Cancer Causes Control. 8:65-72, 1997.
6. Iversen L, Sivasubramaniam S, Lee AJ, Fielding S, Hannaford PC. Lifetime cancer risk and combined oral contraceptives: the Royal College of General Practitioners’ Oral Contraception Study. Am J Obstet Gynecol. 216(6):580.e1-580.e9, 2017.
7. Silvera SAN, Miller AB, Rohan TE. Oral contraceptive use and risk of breast cancer among women with a family history of breast cancer: a prospective cohort study. Cancer Causes Control. 16(9):1059-63, 2005.
8. Dumeaux V, Fournier A, Lund E, Clavel-Chapelon F. Previous oral contraceptive use and breast cancer risk according to hormone replacement therapy use among postmenopausal women. Cancer Causes Control. 16(5):537-44, 2005.
9. Hunter DJ, Colditz GA, Hankinson SE, et al. Oral contraceptive use and breast cancer: a prospective study of young women. Cancer Epidemiol Biomarkers Prev. 19(10):2496-502, 2010.
10. Busund M, Bugge NS, Braaten T, Waaseth M, Rylander C, Lund E. Progestin-only and combined oral contraceptives and receptor-defined premenopausal breast cancer risk: The Norwegian Women and Cancer Study. Int J Cancer. 142(11):2293-2302, 2018.
11. Dumeaux V, Lund E, Hjartaker A. Use of oral contraceptives, alcohol, and risk for invasive breast cancer. Cancer Epidemiol Biomarkers Prev. 13(8):1302-7, 2004.
12. Kumle M, Weiderpass E, Braaten T, Persson I, Adami HO, Lund E. Use of oral contraceptives and breast cancer risk: The Norwegian-Swedish Women’s Lifestyle and Health Cohort Study. Cancer Epidemiol Biomarkers Prev. 11(11):1375-81, 2002.
13. Vessey M, Painter R. Oral contraceptive use and cancer. Findings in a large cohort study, 1968-2004. Br J Cancer. 95(3):385-9, 2006.
14. Elebro K, Butt S, Dorkhan M, Jernström H, Borgquist S. Age at first childbirth and oral contraceptive use are associated with risk of androgen receptor-negative breast cancer: the Malmö Diet and Cancer Cohort. Cancer Causes Control. 25(8):945-57, 2014.
15. Risch HA and Howe GR. Menopausal hormone usage and breast cancer in Saskatchewan: A record-linkage cohort study. Am J Epi. 139(7):670-683, 1994.
16. Thorbjarnardottir T, Olafsdottir EJ, Valdimarsdottir UA, Olafsson O, Tryggvadottir L. Oral contraceptives, hormone replacement therapy and breast cancer risk: a cohort study of 16 928 women 48 years and older. Acta Oncol. 53(6):752-8, 2014.
17. Dorjgochoo T, Shu XO, Li HL, Qian HZ, Yang G, Cai H, Gao YT, Zheng W. Use of oral contraceptives, intrauterine devices and tubal sterilization and cancer risk in a large prospective study, from 1996 to 2006. Int J Cancer. 124(10):2442-9, 2009.
18. Gierisch JM, Coeytaux RR, Urrutia RP, et al. Oral contraceptive use and risk of breast, cervical, colorectal, and endometrial cancers: a systematic review. Cancer Epidemiol Biomarkers Prev. 22(11):1931-43, 2013.
19. Nelson HD, Zakher B, Cantor A, et al. Risk factors for breast cancer for women aged 40 to 49 years: a systematic review and meta-analysis. Ann Intern Med. 156(9):635-48, 2012.

Updated 06/05/24