Rani Bansal, MD: What's Driving Rising Cancer Rates in Young Women and Are We Screening Early Enough?

The latest data from the American Cancer Society have put a spotlight on the fact that breast cancer is rising fastest among women under 50. They report that in women under age 50, the risk of developing cancer is 82% higher than men, which is up 51% from 2022.¹ Rani Bansal, MD, a breast oncologist at Duke University Cancer Center Breast Clinic, notes that for decades, oncologists have thought about breast cancer as something that happens in older patients, not younger patients. New data show that this, however, is changing. What makes the data particularly striking to her is that the rise is concentrated in women younger than 40 years, a group not yet captured by routine screening guidelines, which makes it harder to attribute the trend to improved detection alone.

What's behind it? Bansal explains that there's no single answer and that the most likely explanation is multifactorial. Some factors that may contribute include a convergence of shifting reproductive patterns, rising obesity rates, changing diets, and potentially widespread chemical exposures that may be disrupting endocrine pathways. She points to research comparing women born in the 1950s vs those born in the 1990s, noting that generational birth cohort differences in cancer risk suggest environmental and lifestyle factors are playing a real role.

On screening, Bansal notes that this is a biological increase, not just an artifact of improved detection. Importantly, rates of cancer are also rising in women under age 40, a group that is not routinely screened, which means improved detection alone cannot account for the trend. She supports the updated guidelines recommending mammograms starting at age 40, but argues that for women under 40, a risk-based approach is essential. Starting risk assessments under 40 factoring in family history, prior radiation exposure, and breast density can help identify who needs earlier intervention.

Reference

1. Siegel RL, Kratzer TB, Giaquinto AN, Sung H, Jemal A. Cancer statistics, 2025. CA Cancer J Clin. 2025;75(1):10-45. doi:10.3322/caac.21871