Femara Prevents Breast Cancer Recurrence

Women who survived their first battle with breast cancer may now have a powerful new tool to prevent the dreaded disease from coming back, even years after other treatments have lost their edge.

A major new study announced today shows that the drug Femara picks up where the breast cancer drug tamoxifen leaves off and cuts the risk of breast cancer recurrence nearly in half among postmenopausal women with hormone-dependent breast cancers. The benefits of this therapy were so significant that researchers stopped their study short in order to make the drug available to more women. The results of the study were announced today at a news conference in Toronto and released in advance of the scheduled Nov. 6 publication date in The New England Journal of Medicine. About two-thirds of all breast cancers depend on hormones such as estrogen to grow, and researchers say hundreds of thousands of postmenopausal women worldwide who have had estrogen-sensitive breast cancers may benefit from this new treatment option. Femara Fights Breast Cancer in the Long Run Tamoxifen is a commonly used drug for preventing breast cancer recurrence among postmenopausal women who had hormone-dependent breast cancers. It works by binding to estrogen receptors and depriving breast cancer cells of the estrogen they need. But the benefits of tamoxifen therapy taper off after five years. After that, there has been little doctors could do to reduce the risk of cancer recurrence among these women. “For many years, we have lacked the tools to address the ongoing substantial risk of breast cancer after five years,” says researcher Paul Goss, MD, PhD, of Princess Margaret Hospital in Toronto, who spoke at the briefing. “What is unrecognized by many doctors and patients is that over 50% of recurrences that occur from breast cancer unfortunately occur over the long term, beyond five years after diagnosis,” says Goss. “It becomes a dark cloud that hangs over patients and their families for many years after the primary diagnosis.” The study involved 5,187 postmenopausal women who had completed an average of five years of tamoxifen therapy and compared the effects of a once-a-day Femara pill vs. placebo in preventing breast cancer recurrence. After about two and a half years of follow-up, researchers found Femara appeared to reduce the risk of breast cancer recurrence by nearly half (43%) compared with placebo. Overall, 75 women in the Femara group and 132 in the placebo group developed new breast cancers or other new cancers. Researchers also found a significant difference in the estimated four-year disease-free survival rates between the Femara and placebo users, 93% and 87%, respectively. Goss says that 6% reduction in breast cancer recurrence risk may also continue to grow with longer duration of treatment with Femara and may have a significant impact on reducing deaths due to breast cancer. But he says the number of breast cancer-related deaths in the study was too small to draw any firm conclusions about that yet. Although the study was designed to go on for five years, an independent monitoring committee recommended halting the study so as not to endanger the lives of the women on placebo. (Source: Goss, P. The New England Journal of Medicine, Nov. 6, 2003; vol 349. Webcast, Oct. 9, 2003. Canadian Cancer Society. Harold Burstein, MD, PhD, Dana-Farber Cancer Institute; assistant professor of medicine, Harvard Medical School. FDA. WebMD Medical Reference from Healthwise: “Aromatase Inhibitors for Metastatic Breast Cancer.”: WebMD Health News)