Lactation and Incidence of Premenopausal Breast Cancer: A Longitudinal Study Export

@article{citeulike:5651088, abstract = {Background Findings from observational studies suggest an inverse association between lactation and premenopausal breast cancer risk, but results are inconsistent, and data from large prospective cohort studies are lacking. Methods We used information from 60 075 parous women participating in the prospective cohort study of the Nurses' Health Study II from 1997 to 2005. Our primary outcome was incident premenopausal breast cancer. Results We ascertained 608 incident cases of premenopausal breast cancer during 357 556 person-years of follow-up. Women who had ever breastfed had a covariate-adjusted hazard ratio (HR) of 0.75 (95\% confidence interval [CI], 0.56-1.00) for premenopausal breast cancer compared with women who had never breastfed. No linear trend was found with duration of total lactation (P = .95), exclusive lactation (P = .74), or lactation amenorrhea (P = .88). The association between lactation and premenopausal breast cancer was modified by family history of breast cancer (P value for interaction = .03). Among women with a first-degree relative with breast cancer, those who had ever breastfed had a covariate-adjusted HR of 0.41 (95\% CI, 0.22-0.75) for premenopausal breast cancer compared with women who had never breastfed, whereas no association was observed among women without a family history of breast cancer. Conclusion In this large, prospective cohort study of parous premenopausal women, having ever breastfed was inversely associated with incidence of breast cancer among women with a family history of breast cancer. 10.1001/archinternmed.2009.231}, author = {Stuebe, Alison M. and Willett, Walter C. and Xue, Fei and Michels, Karin B.}, citeulike-article-id = {5651088}, citeulike-linkout-0 = {http://dx.doi.org/10.1001/archinternmed.2009.231}, citeulike-linkout-1 = {http://archinte.ama-assn.org/content/169/15/1364.abstract}, citeulike-linkout-2 = {http://archinte.ama-assn.org/content/169/15/1364.full.pdf}, citeulike-linkout-3 = {http://view.ncbi.nlm.nih.gov/pubmed/19667298}, citeulike-linkout-4 = {http://www.hubmed.org/display.cgi?uids=19667298}, day = {10}, doi = {10.1001/archinternmed.2009.231}, issn = {1538-3679}, journal = {Arch Intern Med}, keywords = {breast, cancer, feeding, lactation, premenopausal}, month = {August}, number = {15}, pages = {1364--1371}, posted-at = {2009-11-05 15:50:08}, priority = {2}, title = {Lactation and Incidence of Premenopausal Breast Cancer: A Longitudinal Study}, url = {http://dx.doi.org/10.1001/archinternmed.2009.231}, volume = {169}, year = {2009} }

TY - JOUR ID - citeulike:5651088 L3 - citeulike-article-id:5651088 N2 - Background Findings from observational studies suggest an inverse association between lactation and premenopausal breast cancer risk, but results are inconsistent, and data from large prospective cohort studies are lacking. Methods We used information from 60 075 parous women participating in the prospective cohort study of the Nurses' Health Study II from 1997 to 2005. Our primary outcome was incident premenopausal breast cancer. Results We ascertained 608 incident cases of premenopausal breast cancer during 357 556 person-years of follow-up. Women who had ever breastfed had a covariate-adjusted hazard ratio (HR) of 0.75 (95% confidence interval [CI], 0.56-1.00) for premenopausal breast cancer compared with women who had never breastfed. No linear trend was found with duration of total lactation (P = .95), exclusive lactation (P = .74), or lactation amenorrhea (P = .88). The association between lactation and premenopausal breast cancer was modified by family history of breast cancer (P value for interaction = .03). Among women with a first-degree relative with breast cancer, those who had ever breastfed had a covariate-adjusted HR of 0.41 (95% CI, 0.22-0.75) for premenopausal breast cancer compared with women who had never breastfed, whereas no association was observed among women without a family history of breast cancer. Conclusion In this large, prospective cohort study of parous premenopausal women, having ever breastfed was inversely associated with incidence of breast cancer among women with a family history of breast cancer. 10.1001/archinternmed.2009.231 IS - 15 JF - Arch Intern Med SN - 1538-3679 EP - 1371 TI - Lactation and Incidence of Premenopausal Breast Cancer: A Longitudinal Study VL - 169 SP - 1364 KW - breast KW - cancer KW - feeding KW - lactation KW - premenopausal AU - Stuebe, Alison AU - Willett, Walter AU - Xue, Fei AU - Michels, Karin PY - 2009/08/10/ UR - http://dx.doi.org/10.1001/archinternmed.2009.231 ER -