Significant Decline in Breast Cancer Mortality Among Women Ages 20–49 Between 2010 and 2020

Between 2010 and 2020, there was a notable reduction in breast cancer-related deaths among women aged 20 to 49 across all molecular subtypes and racial and ethnic groups. This encouraging trend, highlighted in recent data analyzed from the Surveillance, Epidemiology, and End Results (SEER) registry, reflects the impact of advances in treatment and increased screening efforts, especially after 2016.

Despite an overall increase in breast cancer incidence rates among younger women over the past two decades, mortality rates have steadily declined. The study, presented at the AACR Annual Meeting 2025, reviewed data from 11,661 breast cancer deaths in women aged 20–49 over the decade. Researchers evaluated mortality trends by racial/ethnic group and tumor subtype, including luminal A, luminal B, HER2-enriched, and triple-negative breast cancers.

The findings demonstrated a dramatic decline in incidence-based mortality, from 9.70 per 100,000 women in 2010 to just 1.47 per 100,000 in 2020. The most significant decreases were observed in luminal A and triple-negative subtypes, with the largest annual percentage decreases occurring around 2017 and 2018, respectively.

Interestingly, survival outcomes varied by age within the group. Women aged 40-49 with luminal A breast cancer showed the highest 10-year survival rates, whereas women aged 20-39 exhibited lower survival rates for luminal A compared to luminal B. This suggests potential biological heterogeneity in early-onset luminal A tumors that warrants further investigation.

Racial disparities persist, with non-Hispanic Black women experiencing the highest mortality rates and the poorest survival outcomes. However, all racial groups benefited from declining mortality rates, with sharper improvements seen after 2016, likely due to advancements such as targeted therapies, including CDK4/6 inhibitors, and better access to screening and treatment.

Experts believe continued research into tumor biology, molecular mechanisms, and improved access to high-quality care are essential to further reduce mortality and address disparities. Public health initiatives promoting screening in women aged 40–49 and high-risk younger women are vital to sustaining these positive trends.

Overall, these findings highlight significant progress in the fight against breast cancer among young women, emphasizing the importance of ongoing advancements in medicine and health policy to save more lives.