Modeling projects mortality reductions with response-guided breast cancer therapy

Researchers used six Cancer Intervention and Surveillance Network (CISNET) models to estimate breast cancer mortality in the United States from 2018 to 2030 among women eligible for chemotherapy. They compared neoadjuvant therapy followed by response-guided additional adjuvant treatment (NAPAT) with treatment without this added therapy. The models used screening and treatment inputs from clinical trials, national observational studies, and cancer registries; post-2018 trends were assumed to continue as in 2018.

By 2030, NAPAT was projected to reduce the overall breast cancer mortality rate to 23.0 per 100,000 (range across models, 20.6–25.4), a 10.5% reduction (6.5%–14.0%) compared with no NAPAT. Estimated reductions varied by tumor subtype: 30.7% for triple-negative, 27.9% for ER-negative/HER2-positive, and 15.4% for ER-positive/HER2-positive disease. For ER-positive/HER2-negative tumors, the projected change was 1.3% (range, −1.0% to 4.0%), indicating essentially no effect.

These are population-level model projections, not observed outcomes from a clinical trial. Estimates depend on the models’ inputs and the assumption that treatment and screening trends remain unchanged after 2018; the findings do not establish the effect of any specific treatment regimen.