This summary table contains detailed information about research studies. Summary tables offer an informative look at the science behind many breast cancer guidelines and recommendations. However, they should be viewed with some caution. In order to read and interpret research tables successfully, it is important to understand some key concepts. Learn how to read a research table.
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Introduction: Women who are currently using—or have recently used—birth control pills appear to have a slightly increased risk of breast cancer.
A pooled analysis of over 50 studies found a small increase in risk among women who were currently using the pill or had recently used it for 10 or more years [1]. However, this excess risk disappeared 10 years after women stopped using the pill [1].
Most studies to date have looked at older, higher dose forms of the pill. One area still under study is how today's lower-dose pills affect breast cancer risk. At this time, studies are limited.
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 200 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
|
Nurses' Health Study [2]
|
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)
|
Canadian National Breast Screening Study [3]
|
27,318
(1,707 cases)
|
16
|
Current, recent or past use
|
7 or more
years
|
0.74
(0.55-0.99)*
|
E3N cohort - France [4]
|
68,670
(1,405 cases)
|
6
|
Past use
|
10 or more
years
|
0.87
(0.72-1.06)
|
Nurses' Health Study II [5]
|
116,608
(1,344 cases)
|
10.7
|
Current use
|
8 or more
years
|
1.42
(1.05-1.94)
|
Norwegian Women and Cancer Cohort [6]
|
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 [7]
|
103,027
(1,008 cases)
|
7-8†
|
Current or recent use
|
Any length of time
|
1.6
(1.2-2.1)
|
Vessey et al. [8]
|
17,032
(844 cases)
|
30-36
|
Current, recent or past use
|
8 or more
years
|
1.0
(0.8-1.2)
|
Risch et al. [9]
|
33,003
(742 cases)
|
14
|
Past use‡
|
Any length of time
|
1.37
(1.06-1.78)
|
Shanghai Women's Health Study [10]
|
66,661
(558 cases)
|
7.5
|
Current, recent or past use
|
2 or more
years
|
0.93
(0.68-1.25)
|
Netherlands Cohort Study [11]
|
62,573
(471 cases)
|
3.3
|
Current, recent or past use
|
15 or more
years
|
1.09
(0.79-1.48)
|
Miyagi Cohort Study [12]
|
24,064
(285 cases)
|
12.8
|
Current, recent or past use
|
Any length of time
|
0.80
(0.45-1.44)
|
Royal College of General Practioners' Cohort [13]
|
18,000
(239 cases)
|
3.3
|
Current use
|
9 or more
years
|
1.25
(0.84-1.86)
|
|
|
|
Recent or past use
|
10 or more
years
|
1.21
(0.89-1.65)
|
Adventist Health Study [14]
|
20,341
(215 cases)
|
6
|
Current use
|
10 or more
years
|
2.04
(0.71-5.82)
|
|
|
|
Recent or past use
|
10 or more
years
|
1.43
(0.84-2.42)
|
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)
|
Nelson et al. [15]
|
12 studies
|
|
Current use
|
Any length of time
|
1.30
(1.13-1.49)
|
* All women in this study had a family history of breast cancer.
† Follow-up time was estimated from start and end dates of the study.
‡ Past use defined as more than 3.5 years ago.
§ Includes data from prospective cohort studies and case-control studies.
|| Past use defined as 1 to 4 years ago.
¶ Past use defined as 10 to 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. 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.
3. 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.
4. 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.
5. 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.
6. 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.
7. 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.
8. 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.
9. 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.
10. 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.
11. Schuurman AG, van den Brandt PA, Goldbohm RA. Exogenous hormone use and the risk of postmenopausal breast cancer: Results from the Netherlands Cohort Study. Cancer Causes Control. 6:416-424, 1995.
12. Kawai M, Minami Y, Kuriyama S, et al. Reproductive factors, exogenous female hormone use and breast cancer risk in Japanese: the Miyagi Cohort Study. Cancer Causes Control. 21(1):135-45, 2010.
13. Kay CR and Hannaford PC. Breast cancer and the Pill—A further report from the Royal College of General Practitioners' Oral Contraception Study. Br J Cancer. 58(5):675-680, 1988.
14. Mills PK, Beeson WL, Phillips RL, Fraser GE. Prospective study of exogenous hormone use and breast cancer in Seventh-day Adventists. Cancer. 64:591-597, 1989.
15. 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 08/13/12
