In pT1a-pT1b breast cancers, tamoxifen with or without LHRH was the hormonal therapy more frequently administered (85.3%) in premenopausal patients; aromatase inhibitors for 5 years (67.3%) was the endocrine treatment more often utilised in the postmenopausal setting, where tamoxifen for 2–3 years followed by aromatase inhibitor for 3–2 years was administered in 17.1% of patients (Table 8). This evidence concerns the gene CYP19A1 and breast cancer.