Update on the AIs
Hormonal treatments (and, as an aside, isn't it interesting that they are called that as they are really anti-hormonal treatments?) are a major part of care for all women who have ER positive breast cancers. I have written numerous times before (use the search option if you want to find some others) about their importance and about the varying schedules that women follow. It can be disconcerting to learn that some women take Tamoxifen for 5 years and then move to an AI, and some women make that change in 2 or 3 years, and some women start right off with an AI. Clearly, different doctors have different preferences, and the decision is always made with the woman's individual circumstances in mind.
Here is a report, from MedScape, from a recent breast cancer conference with a summary of the current thinking. FYI: Anastrozole is Arimidex. Per usual, I give you a quote and then a link:
Adjuvant Therapy: Update on the ATAC Trial
The ATAC study, a randomized trial that compared 5 years of treatment with tamoxifen with 5 years of treatment with the AI anastrozole, was first presented in 2002.
Investigators presented a 10-year follow-up at BCS 2010. Consistent with findings at the 5- and 8-year follow-up time points, the 10-year follow-up has continued to show a disease-free survival advantage with anastrozole over tamoxifen. Among women with hormone receptor-positive tumors, the 10- year update showed a 4.7% difference in recurrence risk favoring the AI over tamoxifen. There was no difference in overall survival. Long-term follow-up data confirm a greater risk for fracture among women taking anastrozole; however, this risk appears to normalize after the conclusion of adjuvant treatment. As in past analyses, contralateral tumors and ipsilateral breast cancer recurrences comprise a substantial fraction of breast cancer events in this population and contribute in part to the lack of survival difference.
Given the widespread use of adjuvant endocrine therapy and the large number of postmenopausal women diagnosed each year with breast cancer, these data are important because they provide reassurance for the long-term safety.