Researchers map early changes in breast tissue to understand how cancer develops

A multidisciplinary team of surgeons, pathologists, and scientists in Canada recently studied early genetic changes in breast tissue to determine how changes along the lining of the mammary ducts can lead to disease. The results were published in Nature Communications.

As researchers learn more about what causes cancer cells to grow out of control, new therapies can be developed that specifically target these changes to block the growth and spread of the tumor. Targeted therapy is often more effective with fewer side effects than traditional chemotherapy.

"We have found another piece in the cancer puzzle,” said principal investigator Susan Done, PhD, of the Laboratory Medicine Program at Toronto General Hospital in Ontario, Canada. “[This is] knowledge that could one day be used for more precision in screening and breast cancer prevention, and also help with therapeutic approaches to block some of the earliest alterations before cancer develops and starts to spread."

Lead author Moustafa Abdalla explained that studying the earliest mutational events in human breast epithelial cells is technically challenging, so most genomic studies of breast cancer have focused on well-established tumors. In this study, the team found a way to identify early changes that preceded the tumor, which led to a better understanding of cancer biology and disease development.

The researchers were able to map alterations by looking at tissue samples obtained at various distances from normal-looking ducts close to the nipple and close to the tumor, and then compare them to samples on the opposite side of the same breast in eight women. This was achieved by surgically inserting a fiberoptic scope through the nipple into mammary ducts, followed by an injection of dye into the cancerous tissue that was removed. The ductoscopy technique allowed pathologists to identify the exact duct leading to the tumor and classify alterations in genes as they moved closer to the cancer.

The investigators were also able to identify genes that seemed to work together in groups or pathways. Dr. Done indicated that some of the genes were either increased or decreased in the area of the tumor, regardless of the type of breast cancer. This made it possible to identify predictable alterations within the patterns and determine where the sample came from within the breast.

“Our results could have important implications for cancer screening and prevention and could lead the way to new therapeutic approaches and targets,” the investigators concluded.

To read more about this study, click here.