CXCL8 and breast cancer: When restricting the analysis to women not using exogenous hormones, associations remained unchanged, except for a positive association between IL-8 and breast cancer risk overall in all multivariate models (BMI-adjusted: ORper SD increment = 1.22 (1.01–1.48); WC-adjusted: ORper SD increment = 1.22 (1.02–1.46); fully adjusted: ORper SD increment = 1.46 (1.13–1.90), not tabulated).