More Effective Treatment for Younger Women
This study from Switzerland, just reported at a plenary session at ASCO, is big news. Although it is a single study, there certainly will be more research on this issue, and it may become a practice-changing treatment. As you may know, tamoxifen is the standard endocrine/hormonal treatment for pre-menopausal women who have ER positive breast cancers.
The AIs also target estrogen, but they work better for post-menopausal women and have been known to be a bit more effective in this population. There are a number of ongoing studies comparing tamoxifen with an AI plus ovarian suppression in younger woman, and this analysis is the first to be reported. The findings are impressive: a 34% recurrence reduction for women who took Aromasin and ovarian suppression. Here is the start of a report from ASCO's CancerNet and then a link to read more:
Exemestane Plus Ovarian Function Suppression May be a More Effective Alternative
for Premenopausal Women with Early-Stage Breast Cancer
In an analysis of two ongoing studies, researchers found that exemestane (Aromasin) was more effective at preventing hormone sensitive breast cancer from returning for premenopausal women than tamoxifen (Nolvadex, Soltamox) when each drug was paired with ovarian function suppression. Exemestane, an aromatase inhibitor (AI), and tamoxifen are types of hormonal therapy often given as adjuvant therapies to lower the chance of hormone-sensitive breast cancer coming back after other treatments are finished. Hormonesensitive
breast cancer means that the cancer uses the hormones estrogen and/or progesterone to grow.
Although both tamoxifen and AIs such as exemestane are hormonal therapies, they work differently, which affects who can use them. In order for AIs to work effectively, women need to have the low levels of estrogen that naturally occur after menopause, and this is why tamoxifen has been the standard adjuvant hormonal therapy for premenopausal women. In the studies included in this analysis, researchers suppressed ovarian function with medication, surgery to remove the ovaries, or radiation therapy to the ovaries in order to
lower women’s estrogen levels to similar levels they would experience after menopause.
This analysis included information from 4,690 women in two different studies who received either exemestane plus ovarian function suppression or tamoxifen plus ovarian function suppression for five years. Researchers found that the combination of exemestane plus ovarian function suppression reduced the risk of the breast cancer coming back by 34% when compared with tamoxifen plus ovarian function suppression. However, women who received either treatment were equally likely to be alive five years after treatment, with about 96% of women who received exemestane plus ovarian function suppression and about 97% of women who received tamoxifen plus ovarian suppression function alive after five years.