Research Papers: Breast CancerReproductive and hormonal factors, family history, and breast cancer according to the hormonal receptor statusRosato, Valentinaa,b; Bosetti, Cristinaa; Negri, Evaa; Talamini, Renatoc; Dal Maso, Luiginoc; Malvezzi, Matteoa,b; Falcini, Fabiod; Montella, Maurizioe; La Vecchia, Carloa,bAuthor Information aDepartment of Epidemiology, IRCCS – Istituto di Ricerche Farmacologiche ‘Mario Negri’ bDepartment of Clinical Sciences and Community Health, Università degli Studi di Milano, Milan cUnit of Epidemiology and Biostatistics, Centro di Riferimento Oncologico, IRCCS, Aviano (PN) dRegistro Tumori della Romagna, Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST), Meldola (FO) eUnit of Epidemiology, Istituto Tumori ‘Fondazione Pascale’, Naples, Italy Correspondence to Carlo La Vecchia, MD, Department of Epidemiology, IRCCS – Istituto di Ricerche Farmacologiche ‘Mario Negri’, Via Giuseppe La Masa 19, 20156 Milan, Italy Tel: +39 02 39014527; fax: +39 02 33200231; e-mail: [email protected] Received May 15, 2013 Accepted May 27, 2013 European Journal of Cancer Prevention: September 2014 - Volume 23 - Issue 5 - p 412-417 doi: 10.1097/CEJ.0b013e3283639f7a Buy Metrics Abstract The aim of this study was to investigate the association between breast cancer risk, reproductive factors, and family history of breast cancer by the estrogen receptor (ER) and progesterone receptor (PR) status. We analyzed data from an Italian case–control study including 1075 women with incident breast cancer and 1477 hospital controls. We estimated the odds ratios (ORs) of breast cancer using unconditional logistic regression models including major recognized risk factors for breast cancer. Stronger associations with ER+ than with ER− breast cancer were observed for parity (OR: 0.7 vs. 0.9 for ≥3 births vs. nulliparae), age at first birth (OR: 1.6 vs. 1.2 for age ≥30 vs. <25 years), menopausal status (OR: 0.7 vs. 0.8 for postmenopause vs. pre/perimenopause), age at menopause (OR: 1.3 vs. 1.2 for menopause at age ≥50 vs. <50 years), and family history of breast cancer (OR: 2.2 vs. 1.4). Among the ER+ patients, the presence of PR+ did not appreciably modify any of the risk estimates. The association with age at menarche and hormone replacement therapy use was neither significant nor heterogeneous across ER and PR subtypes. In conclusion, we found stronger associations with selected menstrual and reproductive factors for ER+ (PR+) than for ER− (PR−) breast cancers, though in the absence of significant heterogeneity. © 2014 Lippincott Williams & Wilkins, Inc.