Scientists Will Update NCI Breast Cancer Risk Calculator
The formula used for the National Cancer Institute's Breast Cancer Risk Assessment Tool, commonly known as the Gail model,often underestimates the risk of cancer in older black women, according toresearch published Tuesday on the Web site of the Journal of the NationalCancer Institute, the Washington Post reports. The original formula was based ondata from about 240,000 white women.
For the new research, lead author Mitchell Gail -- an NCI biostatistician wholed development of the original model that bears his name -- and colleaguesused data on more than 3,200 black women, including 1,600 who had breastcancer, to re-evaluate the Gail model and seek to develop a better formula forblack women. The researchers tested the newly developed model using data fromthe Women's Health Initiative and found it more accuratelypredicted black women's risk. Next, they compared the two formulas using datacollected from more than 20,000 black women who were screened for eligibilityto participate in the Study of Tamoxifen and Raloxifene trial, which compared the twocancer drugs (Stein, Washington Post, 11/28).
The analysis showed that the old Gail model slightly underestimated the riskfor black women who were older than 45 and that it slightly overestimated riskfor younger black women (USA Today, 11/28). Overall, the old modelunderestimated risk in at least 90% of all scenarios involving black women,especially among older women, the researchers found.
The updated model"could have broad implications for many black women, prompting them toreconsider the danger they face from a disease that is women's leading type ofcancer and second-leading cancer killer," the Post reports. Accordingto the Post, "That could translate into more women undergoingmammograms and other examinations to detect the disease in its earliest, mosttreatable stages; taking drugs such as tamoxifen to reduce their risk; andsigning up for studies to identify better warning signs or risk-reducingmedicines" (Washington Post, 11/28).
The Chicago Tribune reports that black women "likely have been inadvertentlyexcluded" from cancer studies because researchers have used the Gail modelto determine who is at higher risk for the disease (Peres, Chicago Tribune,11/28).
Gail and his team found that for the STAR trial, of the more than 20,000 blackwomen screened for eligibility, only 14% qualified. They determined that hadthe updated model been used, 30% would have qualified for the trial (AP/HoustonChronicle,11/27).
According to the Tribune, researchers "have known the Gailmodel was developed largely from studies of white women and that it might notaccurately assess risk for women of color" (Chicago Tribune,11/28). Gail said he plans to research new models for other groups includingHispanics and Asians (Washington Post, 11/28). NCI's Breast CancerRisk Assessment Tool, which is publicly available online, will be updated usingthe new model in the spring (Chicago Tribune, 11/28).
Gail said, "We've beenconcerned about the assumptions we had to make for African-American women andother racial and ethnic groups for some time," adding, "It turns outthat we have been underestimating the risk for African-American women."
Nancy Davidson, a breast cancer expert who heads the American Society of Clinical Oncology, said, "This could very much change theway we counsel African-American women," adding, "It will make womenbetter attuned to their personal risk and more eligible for standardinterventions, as well as for trials to improve prevention or detection."
Lovell Jones, director of the Center forResearch on Minority Health at the University of Texas M.D. AndersonCancer Center,said, "This is extremely significant. This is emblematic of a broaderproblem, which is: We tend to make the assumption that one size fits all. Onesize does not fit all." Jones added that there are "women whosebreast cancer could have been detected earlier and maybe treated earlier whowere not given that opportunity."
Karen Jackson of Sisters Network, a breast cancer group for black women, said, "It's always beenthought that African-American women were not interested in being part ofclinical trials. In reality, they were denied access to those trials."
Reprintedwith permission from kaisernetwork.org. You can view the entire Kaiser Daily Health Policy Report, search the archives, and sign upfor email delivery at kaisernetwork.org/email . The Kaiser Daily Health PolicyReport is published for kaisernetwork.org, a free service of The Henry J.Kaiser Family Foundation.