The following is a summary of “Extending the Breast Cancer Surveillance Consortium Model of Invasive Breast Cancer,” published in the November 2023 issue of Oncology by Gard, et al.
For a study, researchers sought to enhance the Breast Cancer Surveillance Consortium (BCSC) version 2 (v2) model of invasive breast cancer risk by incorporating body mass index (BMI), extended family history of breast cancer, and age at first live birth (version 3 [v3]). The expansion aimed to provide more comprehensive information for guiding breast cancer prevention strategies and risk-based screening protocols.
Using Cox proportional hazards regression, they estimated age-, race-, and ethnicity-specific relative hazards for family history of breast cancer, breast density, history of benign breast biopsy, BMI, and age at first live birth within the BCSC cohort. Calibration was assessed using the ratio of expected-to-observed (E/O) invasive breast cancers, and discrimination was evaluated using the area under the receiver operating characteristic curve (AUROC).
Data from 1,455,493 women aged 35-79 years without prior breast cancer were analyzed. Over a mean follow-up of 7.3 years, 30,266 women were diagnosed with invasive breast cancer. The BCSC v3 model demonstrated an E/O ratio of 1.03 (95% CI, 1.01 to 1.04) and an AUROC of 0.646 for 5-year risk prediction. Compared to the v2 model, the discriminatory ability of the v3 model showed the most improvement among Asian, White, and Black women. Notably, among women with a BMI of 30.0-34.9 kg/m2, the true-positive rate for those with an estimated 5-year risk of 3% or higher increased from 10.0% (v2) to 19.8% (v3), with even greater enhancement observed in women with a BMI of ≥35 kg/m2 (7.6%-19.8%).
The BCSC v3 model enhances an already well-calibrated and validated tool for assessing breast cancer risk by incorporating additional significant risk factors. The inclusion of BMI resulted in the most substantial improvement in individual risk estimation, providing valuable insights for personalized breast cancer prevention and screening strategies.
Reference: ascopubs.org/doi/10.1200/JCO.22.02470