Advanced Versus Invasive Breast Cancer Risk in a Screening Population: Implications for Risk-based Prevention and Screening Strategies.

BACKGROUND

Most risk-based breast cancer prevention and screening strategies rely on estimated invasive breast cancer risk. A recently developed model from the Breast Cancer Surveillance Consortium (BCSC) identifies women at elevated advanced cancer risk (prognostic pathologic stage II or greater) despite undergoing regular mammography screening.

OBJECTIVE

To describe the characteristics of women identified for risk-based interventions based on advanced versus invasive breast cancer risk.

DESIGN

Cross-sectional study.

PARTICIPANTS

Women aged 40-74 years undergoing mammography screening in routine clinical practice at 165 radiology facilities participating in the BCSC.

MAIN MEASURES: Established BCSC risk models were used to calculate cumulative 6-year advanced breast cancer risk and BCSC 5-year invasive breast cancer risk, stratified by age, race and ethnicity, breast density, and body mass index.

KEY

RESULTS

Among 756,971 included women, the Spearman correlation between advanced and invasive cancer risk scores was 0.75. 31.9% of women had intermediate/high (≥ 0.38%) advanced cancer risk and 32.5% had intermediate/high (≥ 1.67%) invasive cancer risk. 21.1% had intermediate/high risk in both models and 22.1% had intermediate/high risk in only one model. Thirty-five percent of women with intermediate/high invasive cancer risk had low/average advanced cancer risk, and 16% of women with low/average invasive cancer risk had intermediate/high advanced cancer risk. Among women with intermediate/high advanced cancer risk, 17.5% were age 40-49, 25.7% were Black, 69.7% had dense breasts, and 81.1% were overweight/obese. Among women with intermediate/high invasive breast cancer risk, 5.2% were age 40-49, 11.9% were Black, 56.5% had dense breasts, and 70.6% were overweight/obese.

CONCLUSIONS

There are substantial differences in the characteristics of women identified as having elevated risk based on the advanced versus invasive breast cancer risk models. The advanced cancer risk model is important for identifying women who are young, Black, overweight/obese, or have dense breasts at intermediate/higher advanced cancer risk for consideration of risk-based interventions.