Adding Polygenic Risk Score Improves Breast Cancer Risk Prediction for Black Women
, by Jennifer K. Loukissas, M.P.P.
A new study improves prediction of incident breast cancer risk among Black women by adding a polygenic risk score (PRS) to traditional questionnaire-based factors. The findings were published on January 2, 2024, in the journal Breast Cancer Research.
Breast cancer mortality rates are 40% higher in Black women compared to White women, though incidence rates are similar. One approach to addressing this inequity is to improve risk prediction tools so that Black women know their risk and can—together with their clinicians—make informed decisions about the initiation, frequency, and modality of breast cancer screening.
Data for the analysis came from 922 women with invasive breast cancer and 1,844 age-matched controls in the Black Women's Health Study (BWHS), an ongoing prospective cohort study of 59,000 U.S. Black women in the U.S. started in 1995. Ruth Pfeiffer, Ph.D., senior investigator in the Biostatistics Branch, and Professor Julie Palmer and colleagues from Boston University, validated the performance of a previously published PRS that was developed in data from women of African ancestry. They then tested a combined model of PRS and reproductive and clinical risk factors included in the BWHS Breast Cancer Risk Calculator and found the new model was better able to classify women as breast cancer cases or non-cases. Performance metrics matched those of similar models created for women of European ancestry.
The authors hope that when it becomes feasible to incorporate a PRS into routine healthcare, the improvements to risk prediction may mitigate inequities in breast cancer outcomes for Black women. They conclude: “Improved risk prediction for specific subtypes of breast cancer will permit targeted enrollment of Black women into prevention trials so that medications developed will also benefit Black women.”
Zirpoli GR et al. Addition of polygenic risk score to a risk calculator for prediction of breast cancer in US Black women. Breast Cancer Res. 2024.