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 to research published Tuesday on the Web site of the Journal of the National Cancer Institute, the Washington Post reports. The original formula was based on data from about 240,000 white women.
For the new research, lead author Mitchell Gail -- an NCI biostatistician who led development of the original model that bears his name -- and colleagues used data on more than 3,200 black women, including 1,600 who had breast cancer, to re-evaluate the Gail model and seek to develop a better formula for black women. The researchers tested the newly developed model using data from the Women's Health Initiative and found it more accurately predicted black women's risk. Next, they compared the two formulas using data collected from more than 20,000 black women who were screened for eligibility to participate in the Study of Tamoxifen and Raloxifene trial, which compared the two cancer drugs.
The analysis showed that the old Gail model slightly underestimated the risk for black women who were older than 45 and that it slightly overestimated risk for younger black women. Overall, the old model underestimated risk in at least 90% of all scenarios involving black women, especially among older women, the researchers found, the Post reports.
Source: Kaiser Family Foundation