+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Reproductive factors and breast cancer risk according to joint estrogen and progesterone receptor status: a meta-analysis of epidemiological studies



Reproductive factors and breast cancer risk according to joint estrogen and progesterone receptor status: a meta-analysis of epidemiological studies



Breast Cancer Research 8(4): R43



Although reproductive factors have been known for decades to be associated with breast cancer risk, it is unclear to what extent these associations differ by estrogen and progesterone receptor (ER/PR) status. This report presents the first meta-analysis of results from epidemiological studies that have investigated parity, age at first birth, breastfeeding, and age at menarche in relation to ER+PR+ and ER-PR- cancer risk. We calculated summary relative risks (RRs) and corresponding 95% confidence intervals (CIs) using a fixed effects model. Each birth reduced the risk of ER+PR+ cancer by 11% (RR per birth = 0.89, 95% CI = 0.84-0.94), and women who were in the highest age at first birth category had, on average, 27% higher risk of ER+PR+ cancer compared with women who were in the youngest age at first birth category (RR = 1.27, 95% CI = 1.07-1.50). Neither parity nor age at first birth was associated with the risk of ER-PR- cancer (RR per birth = 0.99, 95% CI = 0.94-1.05; RR of oldest versus youngest age at first birth category = 1.01, 95% CI = 0.85-1.20). Breastfeeding and late age at menarche decreased the risk of both receptor subtypes of breast cancer. The protective effect of late age at menarche was statistically significantly greater for ER+PR+ than ER-PR- cancer (RR = 0.72 for ER+PR+ cancer; RR = 0.84 for ER-PR- cancer, p for homogeneity = 0.006). Our findings suggest that breastfeeding (and age at menarche) may act through different hormonal mechanisms than do parity and age at first birth.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 012816138

Download citation: RISBibTeXText

PMID: 16859501

DOI: 10.1186/bcr1525


Related references

Alcohol intake and risk of breast cancer defined by estrogen and progesterone receptor status - A meta-analysis of epidemiological studies. International Journal of Cancer 122(8): 1832-1841, 2008

Alcohol intake and risk of breast cancer defined by estrogen and progesterone receptor status--a meta-analysis of epidemiological studies. International Journal of Cancer 122(8): 1832-1841, 2008

Breast cancer risk factors according to joint estrogen receptor and progesterone receptor status. Cancer Detection and Prevention 29(5): 419-426, 2005

Risk factors for postmenopausal breast cancer differ according to joint estrogen and progesterone receptor status. Proceedings of the American Association for Cancer Research Annual Meeting 34: 264, 1993

Adult weight gain in relation to breast cancer risk by estrogen and progesterone receptor status: a meta-analysis. Breast Cancer Research and Treatment 123(3): 641-649, 2010

Breast cancer risk factors according to combined estrogen and progesterone receptor status: a case-control analysis. American Journal of Epidemiology 146(4): 307-314, 1997

Differences in breast cancer risk factors according to estrogen and progesterone receptor status Case-control analysis. Breast Cancer Research & Treatment 37(Suppl. ): 97, 1996

Dietary fat and risk of breast cancer according to joint estrogen/progesterone receptor status. American Journal of Epidemiology 138(8): 591, 1993

Carotenoid intakes and risk of breast cancer defined by estrogen receptor and progesterone receptor status: a pooled analysis of 18 prospective cohort studies. American Journal of Clinical Nutrition 95(3): 713-725, 2012

Risk of breast cancer classified by joint estrogen receptor and progesterone receptor status among women 20-44 years of age. American Journal of Epidemiology 156(6): 507-516, 2002

Risk factors for breast cancer according to estrogen and progesterone receptor status. Journal of the National Cancer Institute 96(3): 218-228, 2004

Differences in breast cancer risk factors by estrogen and progesterone receptor status. American Journal of Epidemiology 143(11 Suppl. ): S33, 1996

Hormone-related factors and risk of breast cancer by estrogen receptor and progesterone receptor status. American Journal of Epidemiology 147(11 Suppl. ): S35, 1998

Hormone-related factors and risk of breast cancer in relation to estrogen receptor and progesterone receptor status. American Journal of Epidemiology 151(7): 703-714, 2000

Body weight and incidence of breast cancer defined by estrogen and progesterone receptor status--a meta-analysis. International Journal of Cancer 124(3): 698-712, 2009