Rujchanarong D, et al., 2024

The breast stroma is the tissue that surrounds and supports the parts of the breast that make milk—it includes things like fat, blood vessels, and cells that help keep the breast healthy and working properly. Scientists think that changes in this support tissue can help breast cancer get started, even before a tumor can be seen. However, scientists don’t fully understand its role in normal breast tissue or how it may differ between populations. N-glycans, which are complex sugar molecules attached to proteins, are an important part of the stroma. They help control how cells behave and interact with their surroundings. Changes in N-glycan patterns may affect how cancer develops and could help explain why Black women are more likely to have aggressive breast cancers.

To explore these connections, researchers used tissue samples from the Komen Tissue Bank (KTB). They studied N-glycan patterns in normal breast tissue to see how they vary with breast tissue type, density and race. The goal is to understand how the stroma contributes to cancer development in different groups of people.

1. Higher N-glycan Levels in Black Women: Black women with dense breast tissue had higher levels of certain N-glycans. These patterns continued in cancer tissue and were even stronger. Higher levels of certain N-glycans in Black women might explain why breast cancers in Black women are often more aggressive.
2. Fewer Changes in White Women: The patterns in the dense breast tissue of White women looked more like those in less dense tissue, both in normal and cancer tissue.
3. Health Factors Play a Role: In Black women, health factors like higher body weight (BMI) and menopause were linked to changes in the types of N-glycan patterns found in dense breast tissue. These changes weren’t as noticeable in White women, showing that both genetics and lifestyle affect these differences.