| This summary table contains detailed information about research studies. While viewing summary tables offers an informative glimpse at the science behind many breast cancer guidelines and recommendations, they should be viewed with some caution. There are a number of concepts you must understand to be able to successfully read and interpret research tables. To get some background information about understanding research tables, please see How to Read a Research Table. |
Introduction: Overall, there appears to be a small increase in the risk of breast cancer among women who are currently using—or have recently used—birth control pills. Only a few of the large prospective cohort studies listed below show an increase in the risk with pill use. However, one large 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]. This excess risk completely disappeared 10 years after women stopped using the pill [1].
One area under active study is how today's lower dose birth control pills affect the risk of breast cancer. To date, studies are limited.
Find more information on 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: Available prospective cohort studies.
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
|
6
|
Current use
|
Any length of time
|
1.20
(1.00-1.44)
|
|
|
|
Recent or past use
|
>=10 years
|
1.11
(0.94-1.32)
|
Norwegian-Swedish Women's Lifestyle and Health Cohort Study [3]
|
103,027
|
7-8*
|
Current or recent use
|
-
|
1.6
(1.2-2.1)
|
Norwegian Women and Cancer cohort [4]
|
86,948
|
4-10*
|
Current or past use
|
>=10 years
|
1.29
(1.05-1.60)
|
E3N cohort-France [5]
|
68,670
|
6
|
Past use
|
>=10 years
|
0.87
(0.72-1.06)
|
| Shanghai Women's Health Study [6] |
66,661 |
7.5 |
Current, recent or past use |
>=2 years |
0.93
(0.68-1.25)
|
Netherlands Cohort Study [7]
|
62,573
|
3.3
|
Current, recent or past use
|
>=15 years
|
1.09
(0.79-1.48)
|
Risch et al. [8]
|
33,003
|
14
|
Past use†
|
Any length of time
|
1.37
(1.06-1.78)
|
Canadian National Breast Screening Study [9]
|
27,318
|
16
|
Current, recent or past use
|
>=7 years
|
0.74
(0.55-0.99)‡
|
Adventist Health Study [10]
|
20,341
|
6
|
Current use
|
>=10 years
|
2.04
(0.71-5.82)
|
|
|
|
Recent or past use
|
>=10 years
|
1.43
(0.84-2.42)
|
Royal College of General Practitioners' Cohort [11]
|
18,000
|
3.3
|
Current use
|
<=9 years
|
1.25
(0.84-1.86)
|
|
|
|
Recent or past use
|
>=10 years
|
1.21
(0.89-1.65)
|
Vessey et al. [12]
|
17,032
|
16
|
Current, recent or past use
|
>=8 years
|
0.9
(0.7-1.2)
|
Pooled analyses
|
CGHFBC [1]§
|
153,536
|
|
Current use
|
>=10 years
|
1.29
(1.18-1.41)
|
|
|
|
Recent use||
|
>=10 years
|
1.14
(1.04-1.25)
|
|
|
|
Past use¶
|
>=10 years
|
1.01
(0.96-1.05)
|
* Follow-up time was estimated from start and end dates of the study.
† More than 3.5 years ago.
‡ All women in this study had a family history of breast cancer.
§ Includes data from both prospective cohort and case-control studies.
|| 1 to 4 years ago.
¶ 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. 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.
4. 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.
5. 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.
6. 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.
7. 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.
8. 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.
9. 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.
10. 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.
11. Kay CR and Hannaford PC. Breast cancer and the Pill—A further report from the Royal College of General Practitioners' Oral Contraception Study. British Journal of Cancer. 58(5):675-680, 1988.
12. Vessey MP, Villard-Mackintosh L, McPherson K, Yeates D. Mortality among oral contraceptive users: 20 year follow-up of women in a cohort study. BMJ. 299:1487-91, 1989.
Updated 09/12/09
