New Treatment for Young Breast Cancer Survivors
Drug appears more effective than tamoxifen at reducing recurrence in premenopausal women: study
The women, average age 43, all underwent treatment to stop their ovaries from functioning. Each chose one of three methods, Lichtenfeld said -- they could take medication to suppress ovary function, have their ovaries exposed to radiation, or have their ovaries surgically removed.
On top of ovary suppression, the women were randomly assigned to take either exemestane or tamoxifen to help prevent a recurrence of their breast cancer.
The cancer-free survival rate at five years ended up 91.1 percent in the exemestane group versus 87.3 percent in the tamoxifen group. That amounts to a 28 percent lower risk of subsequent invasive cancer, the researchers reported.
There was a 34 percent reduction in the risk of breast cancer recurrence in the exemestane group compared to the tamoxifen group. The study also found a 22 percent decrease in the risk of cancer spreading to other parts of the body.
"This definitely does show that using an aromatase inhibitor is clearly superior than using tamoxifen," said Dr. Larry Norton, deputy physician-in-chief for Breast Cancer Programs and medical director of the Evelyn H. Lauder Breast Center at Memorial Sloan Kettering Cancer Center in New York City. "It provides an important option for these patients."
Reported side effects were similar to those in previous studies that compared aromatase inhibitors and tamoxifen in postmenopausal women, and differed depending on the drug.
Despite the side effects, only 14 percent of the participants completely stopped the treatments early in the five-year trials. That's an adherence rate higher than what is seen in everyday practice, the researchers said. Previous studies suggest that many breast cancer survivors stop taking preventive hormone therapy before the recommended time.
Norton noted that younger breast cancer survivors might be more likely to take their post-treatment medications as directed if they had an alternative to tamoxifen, which is known to increase a woman's risk of endometrial cancer.
The five-year overall survival rates were high in both groups -- 95.9 percent in the exemestane group and 96.9 percent in the tamoxifen group. Longer follow-up is needed to get a better idea of the impact these two treatments will have on long-term survival, the researchers noted.