Breast Cancer Treatment: Weighing the Hormonal Options
Tamoxifen has been the standard in hormonal breast cancer treatment for decades. But newer treatments are challenging tamoxifen's superiority.
Arimidex Beats Out Tamoxifen
In the Arimidex trial, women who switched to the aromatase
inhibitor fared better than if they stayed on standard tamoxifen.
The study followed 448 postmenopausal women who had been taking
tamoxifen for at least two years following breast cancer surgery. The women
were randomly assigned to continue taking tamoxifen or switch to Arimidex for
By three years later, cancer was 64% less likely to recur in
the group of women who switched to Arimidex, the study showed
Other Hormonal News
Those were not the only studies on the new hormonal treatments
Yet another trial showed that women who took Arimidex instead
of tamoxifen were slightly less likely to see their cancer recur after four
years compared with those who took tamoxifen.
And in another study of nearly 300 women, those who took
Arimidex were significantly more likely to become candidates for
breast-conserving surgery than those who took standard tamoxifen, says Ian
Smith, MD, of Royal Marsden Hospital in London.
And in the one trial that pitted Femara against Arimidex, those
on Femara were slightly less likely to respond. But there was no difference in
the amount of time it took for the cancer to grow.
Finally, the largest study ever to evaluate a hormonal therapy
for women with advanced breast cancer showed that those on Femara stayed free
of disease longer than those on tamoxifen.
A Gentler, Milder Drug?
As for side effects, the old standby drug tamoxifen is
associated with a higher risk of uterine cancer than the newer aromatase
inhibitors. But some studies have shown that women taking aromatase inhibitors
are more prone to bone fractures than those taking tamoxifen.
But in general, side effects from aromatase inhibitors are
mild, Goss says. Studies on the various aromatase inhibitors have shown that
the drugs are generally tolerated about as well as placebo and any side effects
appear to be mild. But one side effect in particular, increased bone loss, does
concern doctors, but it has not been seen to be a problem in the short