These meta-analyses supported that alcohol consumption, high BMI (BrCa and ER + , PR + , ER + /PR + BrCa), high body weight (BrCa, ER + /PR + BrCa) and body weight gain in postmenopausal women, high height, P1/ P2/ DY Wolfe grade and high BIRADS/ Breast density classification (BrCa and ER-, ER + BrCa), OC use in premenopausal women, ever active smoking, high androstenedione, estradiol, estrone, and testosterone levels, estrogen-progestin therapy use, high educational level, diabetes mellitus, and digoxin use (BrCa, ER + BrCa) were associated with increased BrCa risk. This evidence concerns the gene ESR1 and diabetes mellitus.