Australian researchers have discovered stem cells in the breast that may be linked to a high-risk form of breast cancer.
Located in a region near the nipple, the newly-found stem cells have many molecular similarities to a subtype of 'triple negative' breast cancers known as claudin-low cancers.
They bear a "striking similarity" and may be the origin of this type of breast cancer, said Professor Jane Visvader from the Walter and Eliza Hall Institute.
If proven, which it hasn't, it's hoped the discovery could lead to more targeted drug treatments and therefore better outcomes for patients.
"Compared to other types of breast cancer, claudin-low cancers have a high chance of recurrence after treatment, leading to a poor prognosis for patients" Prof Visvader said.
The discovery, published in journal Nature Cell Biology, was made as part of a 20-year research program at the Walter and Eliza Hall Institute into how the breast develops from stem cells, and how breast cancers can arise from stem cells and developing breast tissue.
With the use of advanced cellular, bioinformatics and imaging technology they found a 'long-lived' type of stem cell in the breast that is responsible for the growth of the mammary glands during pregnancy.
These stem cells lay dormant and are only activated when exposed to hormones progesterone and oestrogen.
They also express high levels of two proteins called Tetraspanin8 and Lgr5.
"When we looked at the genes that were switched on in these stem cells, we could distinguish subsets of stem cells that differed in their expression of genes encoding two proteins called Tetraspanin8 and Lgr5," said Dr Nai Yang Fu.
About 15 per cent of breast cancers are triple negative. They are different from other types of breast cancer because it does not have any of the three receptors commonly found on breast cancer cells and treatment is often slightly different.
Professor Geoff Lindeman, who is also a medical oncologist at the Peter MacCallum Cancer Centre and The Royal Melbourne Hospital, said the research may lead to future improved outcomes for people with claudin-low cancers.
"We hope that our discovery can be used to understand how cancers may arise from long-lived stem cells, and potentially lead to better outcomes for breast cancer patients in the future," he said.