Compared with controls, non-obese patients with ER+/PR+ breast cancer had significantly higher WBC counts regardless of menopausal status (OR 1.293 95% CI 1.139–1.363, p < 0.001 in premenopausal and OR 1.049 95% CI 1.019–1.295, p = 0.023 in postmenopausal). Here, ESR1 is linked to breast carcinoma.