Table 3 presents the clinicopathological features of premenopausal and postmenopausal breast cancer patients. Most women presented with a unilateral breast lesion. Breast tumors were mainly of ductal histology (82%). Only 1 woman presented a HER2+ tumor and 13 women had an ER+/PR+ tumor. Half of the women had stage 2 breast cancer as classified by TNM score (35). This evidence concerns the gene ESR1 and breast cancer.