Duration of Adjuvant Aromatase-Inhibitor Therapy in Postmenopausal Breast Cancer

The History of Early Breast Cancer Treatment

“…The same studies also show that extending the duration of tamoxifen treatment for up to 10 years proved to further improve outcomes [ 34 , 35 ]. The benefit of extension of AI treatment beyond 5 years is still unclear even though numerous studies were motivated to determine it [ 36 , 37 ].…”

Development of novel agents for the treatment of early estrogen receptor positive breast cancer

“…The optimal duration of adjuvant therapy for patients with early ER+ breast cancer continues to be an area of active investigation even with standard of care endocrine therapy [ 17 , 22 ], and the duration of adjuvant therapy evaluated in escalation trials has been defined empirically. Where most interventions have chronic or cumulative toxicities as well as financial costs that ultimately influence their risk/benefit profiles and clinical adoption, defining optimal durations or surrogate markers that could inform individual management are important goals.…”

“…The establishment of AIs as standard treatment for postmenopausal women with early ER+ breast cancer relied on large randomized trials showing improvement in treatment outcomes and were complemented by data from neoadjuvant trials demonstrating proof of biologic activity [ [19] , [20] , [21] ]. Follow-on randomized adjuvant studies have sought to address other clinical questions, such as treatment duration [ 17 , 22 ].…”

Extended adjuvant aromatase inhibitor therapy: less is more

“…In a recent issue of The New England Journal of Medicine, Gnant et al report the results of the ABCSG-16/SALSA trial that investigated the optimal duration of extended adjuvant aromatase inhibition and found that 5 years was not more beneficial than a 2-year extension. 1…”

“…In a recent issue of The New England Journal of Medicine, Gnant et al reported the results of Austrian Breast and Colorectal Cancer Study Group Trial 16 (ABCSG-16/SALSA, ClinicalTrials.gov number NCT00295620) which addressed whether extension of adjuvant endocrine therapy (using the aromatase inhibitor anastrozole) for 5 years was superior to extension of adjuvant endocrine therapy for 2 years. 1 As aromatase inhibitors are known to be associated with a number of toxicities including menopausal symptoms, arthralgias, bone pain, sexual dysfunction, mood changes, weight gain, cognitive impairments, and treatment-related osteoporosis, the trial addresses an important and highly relevant clinical question. ABCSG-16/SALSA was a randomized, phase 3 clinical trial that enrolled postmenopausal women with resected hormone receptor-positive early breast cancer who had already received 5 years of adjuvant endocrine therapy (with either tamoxifen, an aromatase inhibitor, or both) and remained diseasefree.…”