Aromatase inhibitors have outperformed tamoxifen.

The use of aromatase inhibitors instead of tamoxifen in premenopausal patients with estrogen-positive breast cancer significantly reduces the risk of recurrence. The results of the study were published in The Lancet Oncology.

The use of tamoxifen after surgery in patients with hormone-positive cancer reduces the likelihood of death from cancer within 15 years by a third. At the same time, aromatase inhibitors that suppress estrogen production are superior to tamoxifen in postmenopausal patients, reducing the risk of death by 30%.

However, in a group of premenopausal women, aromatase inhibitors are ineffective, as they increase the production of estrogen by the ovaries. However, this problem can be solved with ovarian suppression therapy or surgery. Until now, it has not been clear what exactly is the most effective therapy in this group of patients to reduce the risk of relapse.

To answer this question, the researchers studied data from more than 7,000 premenopausal women with early-stage breast cancer from around the world. All patients received therapy to suppress ovarian function, and were also divided into groups receiving aromatase inhibitors or tamoxifen for 3 or 5 years. The median follow-up was 8 years.

According to the data obtained, in the study population, 888 (12.6%) patients had a relapse, 418 people died (54 of them from causes not related to oncological disease). Overall, receiving aromatase inhibitors was associated with a 21% reduction in the risk of relapse. The greatest effect was observed during the first five years - the risk in the group of aromatase inhibitors was lower by 32%.