Immune cells in prostate can be activated to destroy cancer cells, research shows

New research shows prostate cancer could be effectively treated with immunotherapy.

The study, funded by the Prostate Cancer Foundation, found immune cells in prostate tissue could be activated to destroy cancer cells.

The research was conducted by Dr Ellie-May Jarvis as part of her PhD with the Malaghan Institute in Wellington. It has been published in the medical journal Frontiers in Immunology.

It found immune cells that can reside in prostate tissue - called MAIT cells, function abnormally and have an abundance of a molecule (PD-1) on their surface.

When the MAIT cells were activated using a vitamin B variant and the PD-1 molecule was blocked, it resulted in anti-tumour activity that destroyed the cancer cells.

Malaghan Institute clinical director Dr Robert Weinkove, who supervised the research, said immunotherapies that effectively treated prostate cancer were not yet a standard of care.

"Most men will develop prostate cancer if they live long enough," Weinkove said.

"It often grows slowly, but can drastically impact the quality of life of those who have it. What is particularly dangerous is if the cancer spreads to other parts of the body such as the bone."

Current treatments for prostate cancer can involve surgery, radiotherapy, chemotherapy, or testosterone inhibitors. Some of which have severe side-effects.

Immunotherapies use an individual's own immune system to target and destroy cancer cells. The therapy is routine for some cancers, but has not been highly effective for prostate cancer to date.

Dr Jarvis said her research involved experimental work using blood cells from healthy donors and people with prostate cancer in the lab.

"More work needs to be done to understand if it can be applied in clinical trials, but it's a promising starting point," Jarvis said.

"We and other researchers in New Zealand and overseas are exploring various immunotherapies that activate MAIT cells, and our research suggests that blocking PD-1 in conjunction with these might be important for cancer therapy."