Breast cancer patients typically do not die because the cancer returns to their breast but because it spreads to other parts of their body, a process called metastases. Patients diagnosed with a form of the disease called HER2-positive breast cancer are at higher risk of developing incurable brain metastases.
Dr Normand Pouliot and his team in the Matrix Microenvironment & Metastasis laboratory are taking two approaches aimed at helping these patients.
Combination therapy could reduce side effects
The laboratory has conducted studies using a combination of drugs to inhibit the spread of HER2 breast cancer.
“Existing HER2 inhibitors have really changed the outcomes for patients with HER2 breast cancer but unfortunately not all patients respond to them, either because they’re inherently resistant to them or they respond initially before resistance almost inevitably occurs,” he says. “What we’re seeing is that a combination of drugs can also act on this resistance. That’s very exciting.”
The researchers have found that combining a potent inhibitor derived from snake venom with existing drugs that inhibit HER2 allowed them to achieve the same efficacy as the HER2 inhibitors alone but at a much lower dose, which could significantly reduce side effects.
“This in vitro research has found that inhibitors from snake venom increases the sensitivity of cells to HER-2 inhibitors up to fifty-fold,” Normand says.
The combination therapy will now be tested in animal models.
Scientists develop model to predict brain metastasis
The lab is also working on a way of detecting the patients who develop the secondary malignant growths; currently they can’t be identified beforehand, meaning that the brain cancer often goes undetected for longer and is more difficult to treat.
“Most patients with brain metastases are diagnosed too late,” Normand says. “There are sophisticated screening tools such as MRI but this is not practical, would be very expensive and therefore not routinely used. Usually by the time symptoms are detected it’s advanced and difficult to treat – surgery can’t be used for many patients and other treatments are just not curative,” Normand says. “If brain metastases can be detected more quickly and treated, treatment is more effective.”
The researchers are currently working to identify a panel of genes – a ‘gene signature’ – that may predict brain metastasis and identify high-risk patients.
Dr Normand Pouliot is Head of the Matrix Microenvironment and Metastasis Laboratory. Read more about their work here.
Read more stories about our breast cancer research:
Minimising the side-effects of breast cancer treatments
Taking on aggressive breast cancer with non-breast cancer drugs
Tackling triple negative breast cancer on two fronts