Breast cancer risk assessments comparing Gail and CARE models in African-American women

The Gail model has been used to predict invasive breast cancer risk in women using risk factors of age, age at menarche, age at first live birth, number of first-degree relatives with breast cancer, and number of previous benign breast biopsies. However, this model underestimates breast cancer risk in African-American women. The Contraceptive and Reproductive Experience (CARE) model has been developed to replace the Gail model in predicting breast cancer risk in African-American women. In a sample of 883 women who participated in the breast cancer screening program at Howard University Cancer Center, we compared the breast cancer risk estimates from the Gail model and the CARE model. The mean 5-year breast cancer risk was 0.88% (Range: 0.18-6.60%) for the Gail model and 1.29% (Range: 0.20-4.50%) for the CARE model. Using the usual cutoff-point of 1.67% or above for elevated risk, there is a significant difference in the proportion of women with elevated breast cancer risk between the Gail and the CARE models (McNemar's test, p < 0.0001). For both models, there was a significant mean risk difference between those with and without a family history of breast cancer (Wilcoxon rank-sum test, p < 0.0001). Our results confirm the need for validation of the Gail model in African-Americans and diversity in research. Although these findings are not perfect and perhaps not definitive, they are additive in the discussions during counseling and risk assessment in African-Americans. Furthermore, these findings will be complemented by new technologies such as genomics in refining our ability to assess risk.