Femara vs. Tamoxifen for Breast Cancer
Femara, Tamoxifen Show Equal Survival Rates in Breast Cancer Study
WebMD News Archive
Aug. 19, 2009 -- Breast cancer patients may do as
well with the drug Femara as they
do with tamoxifen,
a new study shows.
The international study, published in The New England Journal of
Medicine, included more than 6,100 postmenopausal women who had breast cancer that was sensitive to the
hormones estrogen or progesterone.
After the women finished their breast
cancer treatment, they were assigned to one of the following plans:
- Take tamoxifen for five years
- Take Femara for five years
- Take tamoxifen for two years, then Femara for three years
- Take Femara for two years, then tamoxifen for three years
The women didn't know which pills they were taking.
Tamoxifen and Femara work differently. Tamoxifen blocks the action of
estrogen in the body.
Femara belongs to a class of drugs called aromatase
inhibitors. Those drugs, which also include Arimidex and
target the aromatase enzyme, which is needed to make estrogen.
The new study shows that over about six years, the women's odds of
cancer-free survival were equally good taking Femara alone or taking either
tamoxifen first and Femara later or vice versa.
There was no significant difference in overall survival between women who
took Femara alone compared to women who took tamoxifen alone for five years,
report the researchers, who included Henning Mouridsen, MD, chair of the Danish
Breast Cancer Cooperative Group.
2005, the researchers reported that recurrence of breast cancer in sites
far from the breast was less common in women taking Femara than in those taking
The new study shows that the drugs' side effects were in line with known
risks; no unusual adverse events were reported.
The study was funded by Novartis, the drug company that makes Femara. In the
journal, Mouridsen and several other researchers disclose ties to Novartis.
Femara was the only aromatase inhibitor included in the study.