<p>Supplementary Table 1. Summary of the study population in the current analysis.</p><p>Exposure Baseline Number of Total person time Number and reasons Number of questionnaire eligible (person-years) of exclusions cases participants BMI 1980 103,577 1,611,382 for AR+ Cancer before baseline 1,701 AR+ and 1,612,525 for AR- (n= 5,086), death before 497 AR- baseline (n=459), missing BMI (n=2,466), premenopausal women (n=10,112) Weight change 1980 86,882 1,402,382 for AR+ Cancer before baseline 1,520 AR+ and since age 18 y 1,403,399 for AR- (n= 5,086), death before 446 AR- baseline (n=459), missing weight change (n=19,161), premenopausal women (n=10,112) Physical activity 1986 97,803 1,456,642 for AR+ Cancer before baseline 1,661 AR+ and 1,457,799 for AR- (n= 7,388), death before 467 AR- baseline (n=1,626), missing physical activity (n=14,883)</p><p>1 Supplementary Table 2.The correlation between AR and ER/PR status for BMI analysis.</p><p>2 AR ER PR + - + - + 1472 229 1701 1227 474 1701 (84.5) (50.2) (85.5) (62.1) - 270 227 497 208 289 497 (15.5) (49.8) (14.5) (37.9) 1742 456 1435 763</p><p>3 Supplementary Table 3. Multivariable* Relative Risks of Postmenopausal Breast Cancer by AR Status According to Waist Circumference and waist: hip ratio in the Nurses’ Health Study (1986-2006). </p><p>Not accounting for ER/PR status Accounting for ER/PR status P-het** P- Waist circumferences (inches) AR+ (n=857) AR+ (n=857) AR- (n=257) het** 15.0-27.9 1 (ref.) 1 (ref.) 1 (ref.) 28.0-29.9 0.94 (0.76,1.18) 0.95 (0.75,1.19) 1.79 (1.08, 2.95) 30.0-31.9 0.95 (0.74,1.21) 0.94 (0.73,1.21) 1.35 (0.79, 2.31) 32.0-35.9 1.09 (0.84,1.40) 1.17 (0.92,1.50) 1.73 (1.04, 2.86) 36.0-55.0 1.15 (0.84,1.57) 0.98 1.34 (1.00,1.80) 2.13 (1.22, 3.73) 0.12 Waist: hip ratio <0.73 1 (ref.) 1 (ref.) 1 (ref.) 0.73-0.75 1.09 (0.86,1.38) 1.07 (0.84,1.36) 0.79 (0.48, 1.32) 0.75-0.79 0.90 (0.72,1.11) 0.90 (0.72,1.12) 1.02 (0.67, 1.56) 0.79-0.83 1.16 (0.94,1.45) 1.23 (0.99,1.53) 0.94 (0.60, 1.47) ≥ 0.84 1.07 (0.85,1.33) 0.41 1.20 (0.96,1.49) 1.08 (0.70, 1.67) 0.68 *MV-Adjusted for age at menarche, adult body mass index, physical activity, height, parity and age at first birth, alcohol intake, postmenopausal hormone use, age at menopause, family history of breast cancer, and history of benign breast disease. **p-values for heterogeneity between AR+ and AR- tumors.</p><p>4</p>