Preventing Breast Cancer From Recurring by Milayna Subar, M.D. (NAPSA)—Many women have discovered that a conversation with their doctors can help them keep breast cancerat bay. Breast cancer is the most commonly diagnosed form of cancer among womenin the U.S. and the second-leading cause of cancer deaths. Over 190,000 new cases are expected to be diagnosed this year alone. The incidence of breast cancer usually increases with age and occurs primarily in women whoare over 50 yearsold. As treatment of the disease has improved, so too have its survival rates, with 88 percent of women with breast cancer now surviving at least five years. Once a breast cancer has been surgically removed, preventing a recurrence of the disease is key to a woman’s survival. For many women who haveestrogen receptor—positive breast cancer, hormone therapy is used to block the effects of estrogen and prevent recurrence of cancer. One of the most widely used hormonetreatments is tamoxifen, a drug that reduces the risk of breast cancer recurrence by up to 50 percent. Close to 500,000 American women take tamoxifen, with 80,000 new patients starting the treatment each year. Women on tamoxifen may often take other medications as well. Oneclass of drugs that has drawn the attention of breast cancer researchers is the selective serotonin reuptake inhibitors (SSRIs), a group of antidepressant drugs such as Prozac (fluoxetine), Paxil (paroxetine), Zoloft (sertraline), Celexa (citalopram) and Lexapro (escitalopram). One of the most common side effects associated with tamoxifen is menopausal symptoms, which include hot flashes. Antidepressants are used to treat hot flashes as well as depression. As a result, they are commonly prescribed together with tamoxifen. There can be a major problem, however, with taking these drugs together. According to new research by the Indiana University School of Medicine and Medco Health Solutions, Inc., the risk of breast cancer recurrence doubled in women taking some popular SSRIs while being treated with tamoxifen. The three SSRIs that were reported in association with this increase in risk are Prozac, Paxil and Zoloft. Researchers have attributed the effect of these SSRIs on tamoxifen to their inhibitory effect on an enzyme known as CYP2D6. This enzyme is needed to produce the active form of tamoxifen called endoxifen. When this enzyme is prevented from working properly by the inhibitory SSRIs, less endoxifen is produced and tamoxifen becomesless effective at preventing breast cancer. The FDAis currently considering adding a warning label to tamoxifen cautioning against the combination with CYP2D6-inhibiting medications. Women who are on tamoxifen and taking an SSRI should not stop taking either medication on their own but should speak with their doctor about alternative treatments. There are several SSRIs that don’t cause this problem, including Celexa, Lexapro and Luvox (fluvoxamine), as well as non-SSRI antidepressants that are also effective medications. In addition to SSRIs, there are other, less commonly prescribed drugs that have the same effect on tamoxifen, so it’s important that women on the breast cancer drug speak with their doctors about all the medications they are taking. For more information, visit www.medcoresearch.com. Dr. Milayna Subar is the National Practice Leader for the Medco Oncology Therapeutic Resource Center.
