Testing breast cancer tumors for two proteins during surgery may rule out the need for chemotherapy for many breast cancer patients, according to German researchers. The inexpensive tests have already become standard in Europe, but U.S. physicians have been wary of their benefits. At a recent meeting of the American Association for Cancer Research in San Francisco, California, researchers said that using the protein tests help determine the likelihood that breast cancer will return in patients whose lymph nodes do not show any signs of cancer. Approximately 50% of the nearly 183,000 American women diagnosed with invasive breast cancer each year could be affected by the researchers conclusions.
In the study, researchers measured the levels of two proteins found in breast tumors: uPA (urokinase-type plasminogen activator) and PAI-1 (plasminogen activator inhibitor type-1). According to Dr. Anita Prechtl, professor of obstetrics and gynecology at Munich’s Technical University, women with low levels of these proteins had a 95% chance of remaining disease free five years after treatment (surgery and radiation). On the other hand, women with high levels of the proteins only had a 65% chance of being disease free after five years.
Currently, approximately one half of all breast cancers diagnosed in the United States are "node-negative:" the cancer is confined to the breast and has not spread into the axillary (underarm) lymph nodes. For 70% of these patients, breast cancer surgery (either lumpectomy or mastectomy) followed by radiation therapy will successfully treat the cancer. However, in 30% of these patients, breast cancer returns and the patient’s prognosis (outcome) is usually much poorer. Up until now, physicians have had a difficult time predicting which women would experience a recurrence (return) of cancer and so several patients have been prescribed chemotherapy as a precautionary measure even though breast cancer is unlikely to return.
Treatment options have changed some with the increased use of the drug tamoxifen. Many patients with estrogen-receptors on their breast cancer tumors take tamoxifen to help reduce the chances that cancer will return while patients whose tumors are larger than two centimeters are typically given chemotherapy. According to the researchers, if routine protein tests are done on breast tumors, more than 50% of women with node-negative breast cancers may be considered at low risk for cancer recurrence (less than 10% risk) and may not need chemotherapy.
While the prospect of protein tests is promising, many U.S. researchers still want more evidence of the effectiveness of the tests before they stop recommending chemotherapy to patients. Because breast cancer is likely to return within 10 years, additional long-term studies are still needed.
Chemotherapy is treatment with a combination of anti-cancer drugs. The type of drugs, doses, and the duration of treatment depend on the patient’s condition. The side effects of chemotherapy vary greatly from patient to patient. The most common side effects of chemotherapy are: nausea and vomiting, hair loss , and fatigue. Click here to learn more about chemotherapy.
- The April 4, 2000 Associated Press report by Daniel Q. Haney, "Test May Rule Out Chemotherapy Need," is available at http://deseretnews.com/dn/view/0,1249,155015387,00.asp
- The NY Times Syndicate report by Carl T. Hall, "Breast Cancer Tests May Spare Women Chemotherapy," is available at http://www.cancerfacts.com/News.asp?CancerTypeId=5&CB=&NewsId=405
- The April 6, 2000 Imaginis.com report, "Researchers Develop Gel to Prevent Hair Loss from Chemotherapy," at http://www.imaginis.com/breasthealth/news/news4.06.00.asp
