Mayo Clinic Study Finds Risk Assessment Tool Not Reliable Predictor for Some Women at High Risk of Breast CancerNovember 06, 2008ROCHESTER, Minn. - A statistical model commonly used to predict the risk of breast cancer in women was not accurate when used to evaluate women with atypical hyperplasia, according to a new Mayo Clinic study published in the Oct. 14, 2008, issue of the Journal of Clinical Oncology. Atypical hyperplasia (atypia) describes breast tissue with an increased growth of abnormal cells that might become cancerous. The Gail model calculates probabilities that a woman will develop invasive breast cancer during the next five years, and by age 90. The model has come to be called by the name of its developer, National Cancer Institute researcher Mitchell Gail, M.D., Ph.D. Its original purpose was to identify groups of high-risk women for participation in breast cancer chemoprevention studies. But the model has since been used in clinical settings to counsel individuals about their risk of developing breast cancer. Predicting risk at an individual level is much more challenging than when risks can be averaged across groups. "The assumption has always been that this model works well in women with atypia, but this had never been validated," says Shane Pankratz, Ph.D., Mayo Clinic statistician and a lead investigator in the study. "We found that, for the group of women with atypia, the model predicted significantly fewer invasive breast cancers than were actually observed, and we also observed that the model was not able to reliably identify the women who were actually at higher risk of developing breast cancer." The Gail model considers the woman's family history of breast cancer, her age, and her ages at the onset of menstruation and at first live birth, as well as the number of breast biopsies undergone and presence of atypical hyperplasia found in biopsies. About 5 percent of women who undergo biopsies for suspicious lumps or other breast concerns have atypia. About 25 percent of those with atypia will develop cancer within 25 years. Mayo Clinic researchers tested the Gail model in 331 women with atypia who had benign breast biopsies at Mayo Clinic between 1967 and 1991. Of these women, 58 developed cancer during an average of 13.7 years of follow-up. In contrast, the model predicted that 34.9 women would develop breast cancer in that period. Using these and other data, researchers also calculated the model's performance for individuals using the concordance statistic (c-statistic), which reflects how closely the actual timing of breast cancer events aligned with model predictions. A c-statistic of 0.5 is observed if the predictions are no better than random chance; a c-statistic of 1.0 is observed if the predictions are perfectly concordant with the actual outcomes. In this study, the c-statistic was 0.5, reflecting that the Gail model worked no better than a coin flip in predicting which of the women with atypia would develop invasive breast cancer. When assessed across other groups of women without respect to the presence of atypia, the Gail model typically performs better. In that setting, it has been shown to predict approximately the same number of breast cancers that later occur. Lynn Hartmann, M.D., Mayo Clinic oncologist and co-investigator on the study, says that there is strong interest in predicting breast cancer risk. For example, the Gail model, posted on the National Cancer Institute's Web site, attracts 25,000 viewers each month. "Doctors counsel women at high risk to have more frequent or intensive surveillance or to consider chemoprevention strategies such as tamoxifen or raloxifene," says Dr. Hartmann. "When making such decisions, women and their physicians must have highly reliable risk estimates." Researchers are pursuing other avenues to better predict individual risk. Previously, Mayo Clinic researchers found that women with multiple sites of cellular atypia in a breast biopsy have significantly increased risk of developing breast cancer. In a study published earlier this year, Mayo researchers found that women whose atypia tissues express COX-2 enzymes were more likely to develop breast cancer, and the higher the COX-2 levels, the higher the risk. Other Mayo Clinic researchers involved in this study were Judy Boughey, M.D.; Amy Degnim, M.D.; Robert Vierkant; Karthik Ghosh, M.D.; Celine Vachon, Ph.D.: Marlene Frost, Ph.D.; Shaun Maloney and Carol Reynolds, M.D. Mayo Clinic |
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| Related Breast Cancer Current Events and Breast Cancer News Articles New figures on cancer in Europe show a steady decline in mortality but big variations New figures on deaths from cancer in Europe show a steady decline in mortality between the periods 1990-1994 and 2000-2004. Deaths from all cancers in the European Union (EU) between these two periods fell by nine percent in men and eight percent in women, with a large drop among the middle-aged population. Elastography reduces unnecessary breast biopsies Elastography is an effective, convenient technique that, when added to breast ultrasound, helps distinguish cancerous breast lesions from benign results, according to an ongoing study presented today at the annual meeting of the Radiological Society of North America (RSNA). First live targeting of tumors with RNA-based technology Finding and treating a tumor without disturbing normal tissue presents challenges - sometimes the most effective therapies can be invasive and harsh. Menopause-cardiology consensus statement on cardiovascular disease and on HRT A menopause-cardiology consensus statement has called for direct action to prevent cardiovascular disease (CVD) in menopausal women. The statement also concludes that there is little evidence of increased CVD risk in taking HRT. Researchers Identify Role of Gene in Tumor Development, Growth and Progression Virginia Commonwealth University Massey Cancer Center and VCU Institute of Molecular Medicine researchers have identified a gene that may play a pivotal role in two processes that are essential for tumor development, growth and progression to metastasis. UCLA researchers create 'fly paper' to capture circulating cancer cells Just as fly paper captures insects, an innovative new device with nano-sized features developed by researchers at UCLA is able to grab cancer cells in the blood that have broken off from a tumor. Fertility procedures need not delay breast cancer treatment for younger women A new study published in the November issue of the Journal of the American College of Surgeons shows that breast cancer patients under 40 years old who undergo fertility preservation do not face a significant delay in the treatment of their disease when their care is coordinated in a timely fashion. Coffee break: Compound brewing new research in colon, breast cancer A compound in coffee has been found to be estrogenic in studies by Texas AgriLife Research scientists. Drugs to treat anemia in cancer patients linked to thromboembolism Medications frequently given to cancer patients to reduce their risk of anemia are associated with an increased risk of deep vein thrombosis or pulmonary embolism, according to new research led by Dawn Hershman, M.D, M.S., co-director of the breast cancer program at the Herbert Irving Comprehensive Cancer Center at NewYork-Presbyterian Hospital/Columbia University Medical Center. Discovery in worms by Queen's researchers points to more targeted cancer treatment Researchers at Queen's University have found a link between two genes involved in cancer formation in humans, by examining the genes in worms. The groundbreaking discovery provides a foundation for how tumor-forming genes interact, and may offer a drug target for cancer treatment. More Breast Cancer Current Events and Breast Cancer News Articles |
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