Simulation Models Show Breast Cancer Screening and Treatment Advances Are Saving Lives

By: Bryna Goeking
Posted: Wednesday, February 21, 2024

A study focusing on four simulation models from 1975 to 2019 saw a notable decrease in age-adjusted breast cancer mortality rates in the United States. Jennifer L. Caswell-Jin, MD, of Stanford University School of Medicine, California, and colleagues attributed the reduction of mortality to treatment of stage I to III metastatic breast cancer and to screening. In addition, the length of time from recurrence to death increased, as did recurrence-free survival rates from 2000 to 2019.

“Age-adjusted breast cancer mortality rates in the United States were 48 per 100,000 women in 1975 and 27 per 100,000 in 2019,” according to the authors. Screening and treatment were found to be associated with a 58% reduction in mortality rates.

According to the investigators, the reduction in mortality is attributed to new interventions, most dramatically stage I to III treatment followed by metastatic cancer treatment, and to increased screening. Treatment of stage I to III cancers is responsible for 47% of the mortality reduction. Treatment of metastatic breast cancer was associated with a 29% mortality reduction. Increased screening was associated with a 25% reduction, they reported. Although screening was least credited to the reduction in mortality, it remained the most consistent variable across the models. Cancers diagnosed during later screenings were associated with poorer outcomes, regardless of advancements in modern treatment.

Across the four simulation models, the time of metastatic recurrence to death increased, and metastatic recurrence-free survival rates increased. Metastatic breast cancer that recurred was typically caught earlier, and patients lived longer after diagnosis on average. The 5- and 10-year metastatic recurrence-free survival rates increased for 2000 to 2019, with rates varying by cancer and hormone type. However, the study authors acknowledged that their analysis was limited by age, race, ethnicity, access to care, and treatment costs.

Disclosure: For full disclosures of the study authors, visit jamanetwork.com

JAMA

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