One of Australia's most promising prostate cancer researchers believes she's on the cusp of what could be a holy grail discovery in stopping metastatic prostate cancer switching off the body's natural immune response as tumours spread to the bone.
The pioneering research, supported by Prostate Cancer Foundation of Australia (PCFA), could help identify men most at risk of their cancer spreading and make existing therapies more effective.
"We've identified an immune signalling pathway, which is suppressed when cancer cells move from the prostate to bone, making the tumour cells invisible, allowing them to evade the body's natural immune system and enabling the tumour to grow undetected and making them resistant to therapy," said Doctor Katie Owen, who has received two PCFA research grants for her work at the Peter MacCallum Cancer Centre.
"We've found that in certain circumstances we can switch off these cancer cells and stop them expressing proteins which shuts down the good immune responses, creating a pro-tumour environment.
"This discovery is really exciting because if we can make these cells which are invisible seen, then we can explore ways to block it," Dr Owen said.
"It could make existing therapies more effective, even using them in a different way."
PCFA Chief Executive Anne Savage said the findings could transform the treatment of advanced prostate cancer.
"The spread of prostate cancer cells to bone is hard to predict, hard to treat, and hard to beat. This research could help identify men who are most at risk and allow us to deliver targeted therapies to slow down or stop the disease and improve overall survival," Ms Savage said.
Prostate cancer metastasis occurs when cells proliferate and spread beyond the prostate to other parts of the body, often to the bone.
"Prostate cancer is different to other cancers. It's unique in the way it metastasises because it almost always goes to the bone, which makes it even more challenging to treat effectively," Dr Owen said.
"With many of the most deadly forms of prostate cancer, the cancer cells trigger a protein which makes them invisible to the immune system, turning off the immune response that would ordinarily stop the cancer growth. This is where it gets tricky for the body, because the body can't fight what it can't see."
The pre-clinical trials examined and profiled tissue samples of men with metastatic disease, with the scientists looking at not only changes in the primary tumour but also in the metastatic sites themselves.
"Identifying these biomarkers through something like an initial blood test, which is fast and cost-effective could help identify men most at risk, giving them the best chance at survival and also greatly improving their quality of life," Dr Owen said.
PCFA has recently established Australia's first Prostate Cancer Future Fund with the goal of accelerating world-leading research to save the lives of more men.
"Australia has one of the highest rates of prostate cancer in the world. It is a disease that accounts for more hospitalisations than any other type of cancer and claims the lives of more than 3,500 Australian men each year," said PCFA Chief of Mission and Head of Research, Professor Jeff Dunn AO.
Prostate cancer is the most commonly diagnosed cancer in Australia, with around 25,000 men likely to be diagnosed this year.
"While the rate of men dying from prostate cancer in Australia has been gradually falling over the past 20 years, around 10 Australian men still die every day to the disease, and the number of aggressive prostate cancers diagnosed is increasing dramatically as the population ages," Ms Savage said.
"Over the past 40 years five-year relative prostate cancer survival rates have increased from around 61 per cent to 95 per cent. That's a remarkable achievement which demonstrates the impact of research into better diagnosis and treatment," Ms Savage said.
Dr Owen said the research has the potential to make real and achievable change in treatment of the disease, making it less invasive, more effective, affordable to deliver, and easily accessible.
"Research into bone metastasis is often put into the too hard basket and deserves more support. We need to know why treatments are failing and why tumour cells behave differently.
"Ultimately, the work being funded by PCFA right now will help to save lives, minimising the harms of prostate cancer and ensuring all Australian men have an opportunity to beat it before it spreads."
