Researchers conducted a study to understand whether certain genetic variants known to increase breast cancer risk are also linked to the structure of normal breast tissue—specifically, how much the tissue has undergone a process called TDLU involution. TDLUs, or terminal duct lobular units, are the milk-producing structures in the breast where most cancers originate. Involution is a normal aging process where these units shrink and disappear, and less involution has been linked to higher cancer risk. By analyzing breast tissue and genetic data from 872 women, 548 of whom donated healthy breast tissue to the Komen Tissue Bank, researchers examined 62 known breast cancer-related genetic markers to see if they affected TDLU involution.
The study found that only six of the 62 genetic markers were modestly associated with TDLU characteristics such as the number of TDLUs or the number of small glands (acini) within them, suggesting that most breast cancer risk genes may not strongly influence TDLU involution. However, some of the variants showed different effects depending on whether the woman was pre- or postmenopausal. Importantly, the Komen Tissue Bank played a vital role in this research by providing high-quality, non-cancerous breast tissue and data from a diverse group of women, making it possible to study these subtle genetic effects in healthy tissue. The findings highlight the need for larger studies and genome-wide analyses to uncover how genetics shape normal breast tissue and influence cancer risk.
