Experts at the Garvan Institute in Darlinghurst have developed a couple of breakthrough methods for breast cancer treatments that could greatly improve the outcome for individual patients.
Using new microscopic technology, Professor Paul Timpson and Dr Max Nobis developed an imaging technique that focused on Rac1, a type of signalling molecule that shapes cells and helps their movement. However, Rac1 may also make breast cancer cells more aggressive.
Targeting Rac1
By observing and tracking Rac1’s activity within live tumours, the experts were able to determine when breast cancer cells have metastasised.
“We found that Rac1 was most active near blood vessels or at the border of the tumour where cells were primed to move into the bloodstream,” Dr Nobis said.
“Further, we discovered cancer cells could transit to different organs in clusters where Rac1 was more active at the outer surface.
“This helped the cancer cells be more resilient to the physical stresses that occur when cells leave a solid tumour and enter the bloodstream to invade other tissues, such as the lung.”
Targetting this molecule at the right timing, using current non-steroidal anti-inflammatory medications, reduced the spread of cancer cells by 73 percent.
“Based on this data, we speculate that targeting Rac1 in combination with chemotherapy may be most effective at reducing the likelihood of cancer metastasis and recurrence,” the doctor added.
The experts published their findings in Cell Reports.
50 Breast Cancer Subtypes
In another study published in the Nature journal, the Garvan Institute team was able to classify at least 50 breast cancer subtypes after an analysis of breast cancer biopsies among patients across various hospitals in Sydney. The hope is to develop a new diagnostic approach that could improve the ecotype method for clinical diagnostics to help personalise breast cancer treatments.
There are currently three clinical breast cancer subtypes — luminal, HER2+, and triple-negative — that guide doctors on what type of treatments to give patients. However, not all cancers respond to the current strategy thus over 3,000 Australians still die from the disease every year.
“One thing that is characteristic about each ecotype is their profile of immune cells,” Associate Professor Swarbrick said. “We expect that this would relate to a cancer’s response to immunotherapy, and identify patients that could benefit from this treatment.”
“For instance, we found one breast cancer ecotype that uniquely has a high number of infiltrating lymphocytes, which are the target of current immunotherapies, and low levels of cells that we know to suppress lymphocytes. We would predict that those patients would respond well to immunotherapy, which is highly effective in some cancers, such as melanoma or lung cancer, but has a response of less than 10% in breast cancer patients.”
“This study has shown us how crucial the complete cellular profile of tumours is to advancing breast cancer research aimed at personalised treatments.”