for all breast cancer (her2+ patients not specifically)

[Lani]

November 17, 2006 — For postmenopausal women with hormone-sensitive early-stage breast cancer, there is a survival benefit in switching to the aromatase inhibitor anastrozole (Arimidex, AstraZeneca) after an initial period on tamoxifen (Novaldex, AstraZeneca), a new meta-analysis shows.

Combining data from 3 studies revealed a significant improvement in survival with anastrozole, even though none of the studies individually showed this effect, researchers report in a paper published November 17 in Lancet Oncology.

“A lot of people have been waiting to see whether aromatase inhibitors will show a survival advantage, and I think this data will reassure them that 5 years of tamoxifen is no longer the standard of care,” lead author Walter Jonat, MD, from the University of Kiel, in Germany, comments in a statement.

“The best treatment for women with hormone-sensitive early-stage breast cancer should include an aromatase inhibitor,” he says.

Findings Challenge Existing Gold Standard

For the past few decades, the existing gold standard has been 5 years of adjuvant tamoxifen therapy after primary treatment for postmenopausal women with hormone-sensitive early-stage breast cancer. In recent years, however, aromatase inhibitors have been added on or used instead, and such use has been included in guidelines issued by expert bodies such as the American Society for Clinical Oncology (ASCO) and the National Comprehensive Cancer Network (NCCN), the authors note.

“Our findings further challenge the existing standard clinical approach of 5 years’ adjuvant tamoxifen therapy,” they add.

Using Individual Patient Data From 3 Trials

Dr. Jonat and colleagues combined results from 3 trials: the Austrian Breast and Colorectal Cancer Study Group (ABCSG 8), Arimidex-Novaldex (ARNO 95), and the Italian Tamoxifen Anastrozole (ITA) studies. The meta-analysis was sponsored by AstraZeneca.

A total of 4006 women were involved. All the participants had been taking tamoxifen (20 to 30 mg/day) for 2 to 3 years and were then randomized to continuing to take it or to switching to anastrozole (1 mg/day).