Also in the MA.27 trial a 5-year absolute 3% improvement of the event-free survival was observed for the patients receiving osteoporosis therapy in comparison with the patients who did not receive osteoporosis therapy [86% versus 89%, HR 0.63 (95% CI 0.40–1.00)] during adjuvant aromatase inhibitor therapy for breast cancer [18]. Here, CYP19A1 is linked to breast cancer.