PGR and breast cancer: Adjustment for BMI strengthened the positive association between waist (Ptrend = 0.07) and hip (Ptrend = 0.01) circumferences and risk of ER-PR- BC, but, consistent with other studies (Canchola et al. 2012; Potter et al. 1995; Huang et al. 2000), we found no significant association with WHR or WHtR.