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Terminal Duct Lobular Unit Involution of the Normal Breast

Terminal duct lobular units (TDLUs)—also referred to as lobules—are epithelial structures within the breast that produce milk during lactation; they are also the primary anatomical source of most breast cancer precursors and cancers. With completion of childbearing and physiological aging, TDLUs involute (shrink), resulting in a reduction in the number of acini (epithelial substructures) per TDLU and total TDLU counts. Delayed age-appropriate TDLU involution could be associated with increased breast cancer risk because of a higher amount of “at-risk” epithelium. 

We are conducting molecular epidemiologic studies of TDLU involution, which could provide insights into early carcinogenic events. We are performing these studies in collaboration with the Susan G. Komen® Tissue Bank at the Indiana University Simon Cancer Center (KTB)—a unique resource of normal breast tissues, questionnaire data, saliva, and blood donated by volunteers for use in research. Quantitative measures of TDLU involution have been annotated on 1938 women ages 18-74 from this repository without any evidence of breast cancer. The aims of this study are to assess how breast cancer risk factors relate to TDLU involution, which could clarify the natural history of the disease and could lead to novel strategies for risk assessment, early detection and prevention.

For more information, contact Gretchen Gierach.

Integrative Tumor Epidemiology Branch- Research Areas