BRCA1 and breast cancer: In contrast, Qian and colleagues [29] observed a reduction in breast cancer risk with each 5 kg/m2 increase in BMI at adulthood, young-adulthood, and BMI-GS analyses among women with BRCA1/2 pathogenic germline gene variants (adulthood: HR 0.94, 95%CI 0.90,0.98; n = 6964; 3331 events; young-adulthood: HR 0.82, 95%CI 0.75,0.90; n = 5210; 2436 events; BMI-GS: HR 0.87, 95%CI 0.76,0.98; n = 22,588; 11,451 events) [29].