Extended Anastrozole Powder Needed in Breast Cancer



Postmenopausal women with hormone receptor–positive breast cancer who have already taken endocrine therapy for 5 years can proceed with just 2 more years, rather than another 5 years, of additional therapy with the aromatase inhibitor (AI) anastrozole (Arimidex, AstraZeneca), an Austrian study concludes.wisepoqder β-agonist Powder
The 2- and 5-year regimens gave the same reduction in relapse risk but had less adverse effect on bone health, potentially protecting women from fractures.
The results come from the ABCSG-16 trial, a randomized controlled trial of almost 3500 women reported here at the San Antonio Breast Cancer Symposium (SABCS) 2017.

Lead investigator, Michael Gnant, MD, director and chairman of the Department of Surgery, Comprehensive Cancer Center, Medical University of Vienna, Austria, said in a release: "There is simply no rationale to keep most patients on extended AI for longer than two years."
"This result can help save a lot of unnecessary side effects for many women around the world," he said, adding: "I believe that these trial results should be implemented into daily practice at once."
Presenting his findings, Dr Gnant began by highlighting that hormone receptor–positive breast cancer has a significant long-term risk for relapse and that more than 50% of relapses occur after the first 5 years of follow-up.
There has consequently been a tendency to extend the duration of adjuvant hormone therapy. The results of several studies exploring how best to extend therapy have shown that after 5 years of tamoxifen, there is a clear benefit from extended adjuvant therapy with AIs, although the picture is less clear after initial AI treatment.
Dr Gnant said, "So, the question remains: If we extended adjuvant aromatase inhibitors, for how long do we have to treat?"
The researchers therefore undertook the ABCSG-16 trial, in which 3484 postmenopausal women with hormone receptor–positive stage I to III breast cancer from 75 centers in Austria were randomly assigned to 2 years or 5 years of anastrazole, 1 mg/day.
All the women had already undergone 4 to 6 years of endocrine therapy with tamoxifen, an AI, or an AI after tamoxifen following initial surgery with or without radiotherapy.