TY - JOUR A1 - Collaborative Group on Hormonal Factors in Breast Cancer T1 - Breast cancer and breastfeeding: collaborative reanalysis of individual data from 47 epidemiological studies in 30 countries, including 50 302 women with breast cancer and 96 973 women without the disease Y1 - 2002 DO - 10.1016/S0140-6736(02)09454-0 VL - 360 IS - 9328 ER -