AI duration still unclear
“We did not investigate the value of extending adjuvant endocrine therapy per se, since the benefit of extending aromatase inhibitors after 5 years of adjuvant tamoxifen has been well established. In contrast, the most effective duration of adjuvant aromatase inhibitor therapy remains unclear in randomized trials,” Dr. Gnant and colleagues commented.
In her editorial, Dr. Goodwin summarized potential approaches for improving late outcomes for patients with hormone receptor–positive breast cancers, including the use of biomarkers to detect minimal residual disease and therapies to treat it.
She noted that the detection of circulating tumor cells in patients with HR-positive breast cancer 5 years after diagnosis is associated with a 13-fold increase in risk for recurrence and a median time to clinical recurrence of 2.8 years.
“This interval may be sufficiently long that therapeutic intervention can prevent the development of incurable clinical metastases. Continued improvement in these assays and the development of new therapies that target the unique biologic features of dormant cells will no doubt be required for a major reduction in late recurrence risk,” she wrote.
The study was supported by AstraZeneca and the Austrian Breast and Colorectal Cancer Study Group. Dr. Gnant has received lecture fees from AstraZeneca and others. Dr. Goodwin has received institutional research funding from the Breast Cancer Research Foundation and EPIC Sciences.
A version of this article first appeared on Medscape.com.