D. Krebshilfe and D. Krebsforschungszentrum, the Hellenic Health Foundation, the Stavros Niarchos Foundation and the Hellenic Ministry of Health and Social Solidarity; the Italian Association for Research on Cancer (AIRC) and the National Research Council (Italy); the Dutch Ministry of Public Health, Welfare and Sport (VWS), Netherlands Cancer Registry (NKR), LK Research Funds, Dutch Prevention Funds World Cancer Research Fund (WCRF), and Statistics Netherlands (The Netherlands); ERC-2009-AdG 232997 and Nordforsk, the Nordic Centre of Excellence programme on Food, Norway); the Health Research Fund (FIS), Regional Governments of Andalucía, Asturias, Basque Country, Murcia (number 6236) and Navarra, and ISCIII RTICC Red Temática de Investigación Cooperativa en Cáncer (R06/0020) (Spain); the Swedish Cancer Society, Swedish Scientific Council and the Regional Government of Skåne and Västerbotten

P. Preventive, . Medicine, I. Fondazione, and . Istituto-nazionale-dei-tumori, Via Venezian 1

. Federico, 18 Centre for Environment and Health School of Public Health UK. 19 Human Genetics Foundation (HuGeF), Via Nizza 52, Torino,10126, Italy. 20 Public Health and Health Planning Directorate, C/Ciriaco Miguel Virgil 9, Asturias, CP 33006, Spain. 21 Unit of Nutrition, Environment and Cancer Avda Gran Via 199-203, II University Via S. Pansini 5 Naples, 80131, Italy. 17 Cancer Registry and Histopathology Unit Department of Surgery and Perioperative Sciences, pp.30008-31003, 20013.

S. Umeå, SE-901 87, Sweden. 29 National Institute for Public Health and the Environment Antonie van Leeuwenhoeklaan 9 The Netherlands The Netherlands. 31 Julius Center for Health Sciences and Primary Care, University Medical Center, Heidelberglaan 100 The Netherlands. 32 Department of Epidemiology and Biostatistics, School of Public Health, Faculty of Medicine, Imperial College 34 School of Clinical Medicine, University of Cambridge, The Old Schools, Trinity Lane Addenbrooke's Hospital, Hills Road, 901 85, Sweden. 28 Department of Oncology and Radiation Sciences CB2 1TN, UK. 35 Medical Research Council. 37 Nutritional Epidemiology Group, Section of Nutrition and Metabolism, International Agency for Research on Cancer (IARC), 150 Cours Albert Thomas. References 1. Weigelt B, Reis-Filho JS: Histological and molecular types of breast cancer: is there a unifying taxonomy, pp.718-730, 2009.

M. Althuis, J. Fergenbaum, M. Garcia-closas, L. Brinton, M. Madigan et al., Etiology of hormone receptor-defined breast cancer: a systematic review of the literature, Cancer Epidemiol Biomarkers Prev, vol.13, pp.1558-1568, 2004.

E. Rakha, M. Sayed, A. Green, E. Paish, D. Powe et al., Biologic and Clinical Characteristics of Breast Cancer With Single Hormone Receptor???Positive Phenotype, Journal of Clinical Oncology, vol.25, issue.30, pp.4772-4778, 2007.
DOI : 10.1200/JCO.2007.12.2747

C. Perou, T. Sorlie, M. Eisen, R. Van-de, S. Jeffrey et al., Molecular portraits of human breast tumours, Nature, vol.406, issue.6797, pp.747-752, 2000.
DOI : 10.1038/35021093

P. Wirapati, C. Sotiriou, S. Kunkel, P. Farmer, S. Pradervand et al., Meta-analysis of gene expression profiles in breast cancer: toward a unified understanding of breast cancer subtyping and prognosis signatures, Breast Cancer Research, vol.6, issue.4, p.65, 2008.
DOI : 10.1038/nrc1802

R. Suzuki, N. Orsini, S. Saji, T. Key, and A. Wolk, Body weight and incidence of breast cancer defined by estrogen and progesterone receptor status-A meta-analysis, International Journal of Cancer, vol.289, issue.3, pp.698-712, 2009.
DOI : 10.1002/ijc.23943

V. Setiawan, K. Monroe, L. Wilkens, L. Kolonel, M. Pike et al., Breast Cancer Risk Factors Defined by Estrogen and Progesterone Receptor Status: The Multiethnic Cohort Study, American Journal of Epidemiology, vol.169, issue.10, pp.1251-1259, 2009.
DOI : 10.1093/aje/kwp036

M. Cotterchio, N. Kreiger, B. Theis, M. Sloan, and S. Bahl, Hormonal factors and the risk of breast cancer according to estrogen-and progesteronereceptor subgroup, Cancer Epidemiol Biomarkers Prev, vol.12, pp.1053-1060, 2003.

G. Colditz, B. Rosner, W. Chen, M. Holmes, and S. Hankinson, Risk Factors for Breast Cancer According to Estrogen and Progesterone Receptor Status, JNCI Journal of the National Cancer Institute, vol.96, issue.3, pp.218-228, 2004.
DOI : 10.1093/jnci/djh025

R. Chlebowski, G. Anderson, M. Gass, D. Lane, A. Aragaki et al., Estrogen Plus Progestin and Breast Cancer Incidence and Mortality in Postmenopausal Women, JAMA, vol.304, issue.15, pp.1684-1692, 2010.
DOI : 10.1001/jama.2010.1500

H. Feigelson, C. Jonas, L. Teras, M. Thun, and E. Calle, Weight Gain, Body Mass Index, Hormone Replacement Therapy, and Postmenopausal Breast Cancer in a Large Prospective Study, Cancer Epidemiology Biomarkers & Prevention, vol.13, issue.2, pp.220-224, 2004.
DOI : 10.1158/1055-9965.EPI-03-0301

L. Morimoto, E. White, Z. Chen, R. Chlebowski, J. Hays et al., Obesity, body size, and risk of postmenopausal breast cancer: the Women's Health Initiative (United States). Cancer Causes Control, pp.741-751, 2002.

P. Lahmann, K. Hoffmann, N. Allen, C. Van-gils, K. Khaw et al., Body size and breast cancer risk: Findings from the European prospective investigation into cancer and nutrition (EPIC), Body size and breast cancer risk: findings from the European Prospective Investigation into Cancer And Nutrition (EPIC), pp.762-771, 2004.
DOI : 10.1002/ijc.20315

E. Riboli and R. Kaaks, The EPIC Project: rationale and study design. European Prospective Investigation into Cancer and Nutrition, International Journal of Epidemiology, vol.26, issue.90001, pp.6-14, 1997.
DOI : 10.1093/ije/26.suppl_1.S6

M. Haftenberger, P. Lahmann, S. Panico, C. Gonzalez, J. Seidell et al., Overweight, obesity and fat distribution in 50-to 64-year-old participants in the European Prospective Investigation into Cancer and Nutrition (EPIC) Public Health Nutr, pp.1147-1162, 2002.

E. Spencer, P. Appleby, G. Davey, and T. Key, Validity of self-reported height and weight in 4808 EPIC???Oxford participants, Public Health Nutrition, vol.5, issue.4, pp.561-565, 2002.
DOI : 10.1079/PHN2001322

K. Bakken, A. Fournier, E. Lund, M. Waaseth, V. Dumeaux et al., Menopausal hormone therapy and breast cancer risk: Impact of different treatments. The European Prospective Investigation into Cancer and Nutrition, International Journal of Cancer, vol.15, issue.suppl 1, pp.144-156, 2011.
DOI : 10.1002/ijc.25314

J. Harvey, G. Clark, C. Osborne, and D. Allred, Estrogen Receptor Status by Immunohistochemistry Is Superior to the Ligand-Binding Assay for Predicting Response to Adjuvant Endocrine Therapy in Breast Cancer, Journal of Clinical Oncology, vol.17, issue.5, pp.1474-1481, 1999.
DOI : 10.1200/JCO.1999.17.5.1474

J. Mccann, Better Assays Needed for Hormone Receptor Status, Experts Say, JNCI Journal of the National Cancer Institute, vol.93, issue.8, pp.579-580, 2001.
DOI : 10.1093/jnci/93.8.579

L. Layfield, D. Gupta, and E. Mooney, Assessment of Tissue Estrogen and Progesterone Receptor Levels: A Survey of Current Practice, Techniques, and Quantitation Methods, The Breast Journal, vol.6, issue.3, pp.189-196, 2000.
DOI : 10.1046/j.1524-4741.2000.99097.x

J. Flowers, G. Burton, E. Cox, K. Mccarty, G. Dent et al., Use of Monoclonal Antiestrogen Receptor Antibody to Evaluate Estrogen Receptor Content in Fine Needle Aspiration Breast Biopsies, Annals of Surgery, vol.203, issue.3, pp.250-254, 1986.
DOI : 10.1097/00000658-198603000-00005

W. Remmele and H. Stegner, Recommendation for uniform definition of an immunoreactive score (IRS) for immunohistochemical estrogen receptor detection (ER-ICA) in breast cancer tissue], Pathologe, vol.8, pp.138-140, 1987.

C. Li, K. Malone, and J. Daling, Interactions between body mass index and hormone therapy and postmenopausal breast cancer risk (United States) Cancer Causes Control, pp.695-703, 2006.

N. Wareham, R. Jakes, K. Rennie, J. Schuit, J. Mitchell et al., Validity and repeatability of a simple index derived from the short physical activity questionnaire used in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Public Health Nutr, pp.407-413, 2003.

M. Lunn and D. Mcneil, Applying Cox Regression to Competing Risks, Biometrics, vol.51, issue.2, pp.524-532, 1995.
DOI : 10.2307/2532940

D. Altman, D. Stavola, B. Love, S. Stepniewska, and K. , Review of survival analyses published in cancer journals, British Journal of Cancer, vol.72, issue.2, pp.511-518, 1995.
DOI : 10.1038/bjc.1995.364

R. Tarone and K. Chu, The greater impact of menopause on ER-than ER+ breast cancer incidence: a possible explanation (United States) Cancer Causes Control, pp.7-14, 2002.

Y. Yasui and J. Potter, The shape of age-incidence curves of female breast cancer by hormone-receptor status, Cancer Causes and Control, vol.10, issue.5, pp.431-437, 1999.
DOI : 10.1023/A:1008970121595

K. Chu, W. Anderson, A. Fritz, L. Ries, and O. Brawley, Frequency distributions of breast cancer characteristics classified by estrogen receptor and progesterone receptor status for eight racial/ethnic groups, Cancer, vol.53, issue.Suppl, pp.37-45, 2001.
DOI : 10.1002/1097-0142(20010701)92:1<37::AID-CNCR1289>3.0.CO;2-F

L. Dunnwald, M. Rossing, and C. Li, Hormone receptor status, tumor characteristics, and prognosis: a prospective cohort of breast cancer patients, Breast Cancer Research, vol.9, issue.1, p.6, 2007.
DOI : 10.1186/bcr1639

W. Anderson, N. Chatterjee, W. Ershler, and O. Brawley, Estrogen Receptor Breast Cancer Phenotypes in the Surveillance, Epidemiology, and End Results Database, Breast Cancer Research and Treatment, vol.15, issue.Suppl8, pp.27-36, 2002.
DOI : 10.1023/A:1020299707510

M. Dietel, M. Lewis, and S. Shapiro, Hormone replacement therapy: pathobiological aspects of hormone-sensitive cancers in women relevant to epidemiological studies on HRT: a mini-review, Human Reproduction, vol.20, issue.8, pp.2052-2060, 2005.
DOI : 10.1093/humrep/dei043

D. Allred, P. Brown, and D. Medina, The origins of estrogen receptor alpha-positive and estrogen receptor alpha-negative human breast cancer, Breast Cancer Research, vol.6, issue.6, pp.240-245, 2004.
DOI : 10.1023/A:1011308707512

V. Jordan, The Ups and Downs of the Estrogen Receptor, Journal of Clinical Oncology, vol.21, issue.1, pp.3-4, 2003.
DOI : 10.1200/JCO.2003.10.008

M. Asselin-labat, F. Vaillant, J. Sheridan, B. Pal, D. Wu et al., Control of mammary stem cell function by steroid hormone signalling, Nature, vol.21, issue.7299, pp.798-802, 2010.
DOI : 10.1038/nature09027

H. Harris, W. Willett, K. Terry, and K. Michels, Body Fat Distribution and Risk of Premenopausal Breast Cancer in the Nurses' Health Study II, JNCI Journal of the National Cancer Institute, vol.103, issue.3, pp.273-278, 2011.
DOI : 10.1093/jnci/djq500

A. Phipps, R. Chlebowski, R. Prentice, A. Mctiernan, M. Stefanick et al., Body Size, Physical Activity, and Risk of Triple-Negative and Estrogen Receptor-Positive Breast Cancer, Cancer Epidemiology Biomarkers & Prevention, vol.20, issue.3, pp.454-463, 2011.
DOI : 10.1158/1055-9965.EPI-10-0974

E. John, M. Sangaramoorthy, A. Phipps, K. J. Horn-ross, and P. , Adult Body Size, Hormone Receptor Status, and Premenopausal Breast Cancer Risk in a Multiethnic Population: The San Francisco Bay Area Breast Cancer Study, American Journal of Epidemiology, vol.173, issue.2, pp.201-216, 2011.
DOI : 10.1093/aje/kwq345

S. Hankinson, Endogenous Hormones and Risk of Breast Cancer in Postmenopausal Women, Breast Disease, vol.24, issue.1, pp.3-15, 2005.
DOI : 10.3233/BD-2006-24102

T. Key, N. Allen, P. Verkasalo, and E. Banks, Energy balance and cancer: the role of sex hormones, Proceedings of the Nutrition Society, vol.57, issue.01, pp.81-89, 2001.
DOI : 10.1210/jcem-53-1-58

D. Rose and L. Vona-davis, Interaction between menopausal status and obesity in affecting breast cancer risk, Maturitas, vol.66, issue.1, pp.33-38, 2010.
DOI : 10.1016/j.maturitas.2010.01.019

A. Eliassen, S. Missmer, S. Tworoger, D. Spiegelman, R. Barbieri et al., Endogenous Steroid Hormone Concentrations and Risk of Breast Cancer Among Premenopausal Women, JNCI Journal of the National Cancer Institute, vol.98, issue.19, pp.1406-1415, 2006.
DOI : 10.1093/jnci/djj376

R. Kaaks, F. Berrino, T. Key, S. Rinaldi, L. Dossus et al., Serum Sex Steroids in Premenopausal Women and Breast Cancer Risk Within the European Prospective Investigation into Cancer and Nutrition (EPIC), JNCI Journal of the National Cancer Institute, vol.97, issue.10, pp.755-765, 2005.
DOI : 10.1093/jnci/dji132

L. Rosenberg, K. Einarsdottir, E. Friman, S. Wedren, P. Dickman et al., Risk Factors for Hormone Receptor-Defined Breast Cancer in Postmenopausal Women, Cancer Epidemiology Biomarkers & Prevention, vol.15, issue.12, pp.2482-2488, 2006.
DOI : 10.1158/1055-9965.EPI-06-0489

V. Beral, G. Reeves, D. Bull, and J. Green, Breast Cancer Risk in Relation to the Interval Between Menopause and Starting Hormone Therapy, JNCI Journal of the National Cancer Institute, vol.103, issue.4, pp.296-305, 2011.
DOI : 10.1093/jnci/djq527

A. Fournier, A. Fabre, S. Mesrine, M. Boutron-ruault, and F. Berrino, Use of Different Postmenopausal Hormone Therapies and Risk of Histology- and Hormone Receptor???Defined Invasive Breast Cancer, Journal of Clinical Oncology, vol.26, issue.8, pp.1260-1268, 2008.
DOI : 10.1200/JCO.2007.13.4338
URL : https://hal.archives-ouvertes.fr/inserm-00271114

A. Tjonneland, J. Christensen, B. Thomsen, A. Olsen, K. Overvad et al., Hormone replacement therapy in relation to breast carcinoma incidence rate ratios, Cancer, vol.80, issue.11, pp.2328-2337, 2004.
DOI : 10.1002/cncr.20250

W. Chen, S. Hankinson, S. Schnitt, B. Rosner, M. Holmes et al., Association of hormone replacement therapy to estrogen and progesterone receptor status in invasive breast carcinoma, Cancer, vol.98, issue.7, pp.1490-1500, 2004.
DOI : 10.1002/cncr.20499

T. Saxena, E. Lee, K. Henderson, C. Clarke, D. West et al., Menopausal Hormone Therapy and Subsequent Risk of Specific Invasive Breast Cancer Subtypes in the California Teachers Study, Cancer Epidemiology Biomarkers & Prevention, vol.19, issue.9, pp.2366-2378, 2010.
DOI : 10.1158/1055-9965.EPI-10-0162

N. Magne, R. Toillon, P. Castadot, A. Ramaioli, and M. Namer, Different clinical impact of estradiol receptor determination according to the analytical method: a study on 1940 breast cancer patients over a period of 16 consecutive years, Breast Cancer Research and Treatment, vol.117, issue.5, pp.179-184, 2006.
DOI : 10.1007/s10549-005-9065-z

G. Chebil, P. Bendahl, I. Idvall, and M. Ferno, Comparison of immunohistochemical and biochemical assay of steroid receptors in

A. Welsh, C. Moeder, S. Kumar, P. Gershkovich, E. Alarid et al., Standardization of Estrogen Receptor Measurement in Breast Cancer Suggests False-Negative Results Are a Function of Threshold Intensity Rather Than Percentage of Positive Cells, Journal of Clinical Oncology, vol.29, issue.22, pp.2978-2984, 2011.
DOI : 10.1200/JCO.2010.32.9706

K. Hede, Breast Cancer Testing Scandal Shines Spotlight on Black Box of Clinical Laboratory Testing, JNCI Journal of the National Cancer Institute, vol.100, issue.12, pp.836-843, 2008.
DOI : 10.1093/jnci/djn200

M. Hammond, D. Hayes, M. Dowsett, D. Allred, K. Hagerty et al., American Society of Clinical Oncology/College of American Pathologists Guideline Recommendations for Immunohistochemical Testing of Estrogen and Progesterone Receptors in Breast Cancer, Journal of Clinical Oncology, vol.28, issue.16, pp.2784-2795, 2010.
DOI : 10.1200/JCO.2009.25.6529

A. Goldhirsch, J. Ingle, R. Gelber, A. Coates, B. Thurlimann et al., Thresholds for therapies: highlights of the St Gallen International Expert Consensus on the Primary Therapy of Early Breast Cancer 2009, Annals of Oncology, vol.20, issue.8, pp.1319-1329, 2009.
DOI : 10.1093/annonc/mdp322