Large Study Shows Femara May Be More Effective Than Tamoxifen at Treating Early-Stage Breast Cancer (dateline February 21, 2005)
Recent results of an ongoing study show that the drug Femara (generic name letrozole) may be more effective at treating early-stage breast cancer in post-menopausal women than the standard drug, tamoxifen (brand name, Nolvadex). According the study of more than 8,000 participants, post-menopausal women treated with Femara had a 19% reduced risk of relapsing and a 27% reduced risk that breast cancer would spread to other body organs, compared with those treated with tamoxifen. The study is being conducted by researchers of the International Breast Cancer Study Group, a non-profit group, in 27 countries. Financial support for the study was provided by Novartis, the manufacturer of Femara.
Results at the 26-month point in the Breast International Group (BIG) I-98 trial were presented in late January at the Primary Therapy of Early Breast Cancer 9th International Conference in St. Gallen, Switzerland. "We now have an additional tool to improve the outcome for post-menopausal women with hormone sensitive breast cancer. Together with optimal surgery, followed by chemotherapy and radiotherapy if needed, incorporation of letrozole [Femara] in the treatment plan is a step forward in the patients way of remaining disease from cancer. Further investigations and longer follow-up are necessary to optimize the use of letrozole [Femara] in order establish long-term safety and tolerability of the drug and to further improve its treatment benefits," said BIG 1-98 Trial study chair, Dr. Thürlimann, in an International Breast Cancer Study Group news release.
In the study, Femara was effective in women with early-stage estrogen-receptor positive breast cancer. Early-stage breast cancer is cancer that has not spread past the breast and/or underarm lymph nodes. Most early-stage breast cancer patients undergo surgery as may also receive radiation and/or chemotherapy. About 80% of breast cancer cases are estrogen sensitive, meaning that the cancer cells depend on estrogen for survival and reproduction. Tamoxifen is also indicated for estrogen sensitive breast cancers.
The BIG I-98 trial is the first of its kind to directly compare Femara and tamoxifen in post-menopausal women with early-stage breast cancer during the first five years after surgery. The study is ongoing and comparing the following:
According to International Breast Cancer Study Group, patients on Femara and tamoxifen experienced different side effects.
Women given tamoxifen were more likely to experience:
Women given Femara were more likely to experience:
Both groups of patients experienced slightly more heart attacks and strokes on the drugs, though these events were very rare with both treatments.
The researchers caution that study results involving long periods of follow-up are needed to better understand the long-term safety and effectiveness of Femara in treating early-stage breast cancer. They are currently continuing the BIG I-98 trial.
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