A Breast Cancer Risk Assessment Tool That Includes Breast Density Measures

A risk model, developed using 2000 to 2010 SEER data for breast cancer incidence and 2010 vital statistics, found that incorporating breast density information in the risk calculator could accurately estimate women’s risk for the disease. The model—called the Breast Cancer Surveillance Consortium benign breast disease (BCSC BBD)—identified more number of high-risk women eligible for primary prevention after diagnosis of BBD, according to study results published in the Journal of Clinical Oncology.

According to study author Charlotte Gard, a biostatistician, “Our tool is unique in that it combines both breast density and biopsy results,” Gard explained. “It’s the only risk assessment tool that includes BI-RADS [Breast Imaging Reporting and Data System of the American College of Radiology] breast density, which is the breast density that’s used in clinical practice.”

The study included data on 1,135,977 women between 35 and 74 years of age who had a mammography, but no history of breast cancer; 17% of these women had a prior breast biopsy. Nearly 18,000 women in this cohort were diagnosed with an invasive form of breast cancer during a mean follow up of 6.9 years. While the group’s BCSC BBD model slightly overpredicted risk, the authors write, with an expected-to-observed ratio of 1.04, including BBD in the risk calculator for women with proliferative disease significantly increased the proportion of women with an estimated 5-year risk of 3% or higher from 9.3% to 27.8%.

The authors hope that their results will help raise awareness on the impact of breast density on susceptibility to breast cancer. While only 24 states currently require women with a breast density of “c” or “d” to be notified by their radiologist, federal legislation to make this a nationwide requirement is being considered. This will help stimulate a dialogue between women and their healthcare providers on how their dense breasts would impact their risk.

The tool is available at https://tools.bcsc-scc.org/BC5yearRisk.