Duration of adjuvant aromatase-inhibitor therapy in postmenopausal breast cancer

For postmenopausal women with hormone-receptor-positive breast cancer, the optimal duration for adjuvant therapy with an aromatase inhibitor is not clear. The phase 3 ABCSG-16/SALSA study, at 75 centers in Austria, randomized postmenopausal women after 5 years adjuvant anastrozole therapy for HR-positive breast cancer to an additional 2 years or an additional 5 years of anastrozole. There were no significant differences between the two groups in DFS (primary end point), OS, contralateral breast cancer or second primary cancer. The risk of clinical bone fracture was higher in the 5-year group than in the 2-year group (HR 1.35; 95% CI 1,00-1,84).