1975 to 2019 saw 58% decrease in breast cancer mortality

In the United States, breast cancer screening and treatment were associated with a 58% reduction in breast cancer mortality in 2019 compared with 1975, according to a study published in the Jan. 16 issue of the Journal of the American Medical Association.

Jennifer L. Caswell-Jin, M.D., from the Stanford University School of Medicine in California, and colleagues simulated the relative association of breast cancer screening, treatment of stage I to III breast cancer, and treatment of metastatic breast cancer with improved mortality using aggregated observational and clinical trial data on the dissemination and effects of screening and treatment.

The researchers found that the age-adjusted breast cancer mortality rate in the United States was 48/100,000 women in 1975 and 27/100,000 women in 2019. The combination of screening, stage I to III treatment, and metastatic treatment was associated with a 58% reduction in breast cancer mortality in 2019; 29, 47, and 25% of the reduction was associated with treatment of metastatic breast cancer, treatment of stage I to III breast cancer, and mammography screening, respectively. The greatest change in survival after metastatic recurrence occurred between 2000 and 2019 based on simulations, from 1.9 to 3.2 years.

"The results suggest that advances in the treatment of metastatic breast cancer were associated with lower rates of breast cancer mortality in the United States," the authors write.