Scientists identify genetic play behind breast cancer recurrence
Undetectable microscopic pieces of tumour that remain after a mastectomy are a major factor for the recurrence of breast cancer – scientists from Georgetown University Medical Center in Washington, DC, have recently discovered cell types with significant genetic changes that could kick-start recurrence.
The discovery was made possible by an advanced technology developed at Georgetown Lombardi Comprehensive Cancer Center (Georgetown Lombardi) that allows laboratory researchers to expand, or multiply, hard-to-extract breast tissue cells.
Up to 15% of women, those with hormone-receptor positive breast cancer especially, have a high risk of recurrence, sometimes years after surgery and aggressive follow-up.
“When a person is diagnosed with breast cancer, we have several tools, including testing for genes such as BRCA1/2, to decide whether they should get certain kinds of chemotherapy or just receive hormonal therapy. But the tools we have are not as precise as we would like,” admitted Dr. Priscilla Furth, professor of oncology and medicine at Georgetown Lombardi.
With the new technology, Dr. Furth and fellow scientists were able to extract breast epithelial cells, the layer of cells that form the ducts and lobes which make milk during lactation, from suspected non-cancerous breast tissue. The scientists noted dramatic changes in RNA sequences in the epithelial cells which were later recognised as prognostic indicators for cancer.
RNA sequences known as the transcriptome help determine when and where each gene is turned on or off in a cell, preventing uncontrolled division of cellular components and eventual mutation.
Some of the RNA changes discovered were linked to mammary stem cell formation: mammary stem cells are adult stem cells that can differentiate, or change function, into specialised mammary epithelial cells. If these cells get dysregulated, there is an increased potential for cancer. Cells from pregnant women could potentially trigger extra renewing cycles in a cell, thus increasing the risk of cancer.
“About one in eight women are diagnosed with breast cancer in the developed world. […] Many of our cancer survivors say to me, ‘please do work that will benefit my daughter.’ My response is that’s why I’m in the field of cancer prevention.
“Anything we can do to prevent the occurrence or recurrence of cancer is a significant step forward and we think this finding may be an important contribution to reducing misdiagnosis as well as point to ways to develop better therapies to treat the disease,” said Dr. Furth.
Read: New tool for more accurate detection of breast cancer in Asian women
