Immunotherapies have revolutionised the treatment of certain cancer types but have been largely unsuccessful in prostate cancer, despite many clinical trials.

New research at Flinders hopes to change that by investigating whether a hormonal therapy can alter the immune system in a way that sensitises prostate cancer cells to immunotherapy, making immunotherapy more effective in treating – and potentially curing – prostate cancer.

“It’s probably one of the most pressing clinical issues in prostate cancer, how do we make these tumours more responsive to immunotherapy?” said Associate Professor Luke Selth from Flinders University.

“Immunotherapy has been amazing in some cancer types, for example melanoma and some lung cancers. Some advanced cancer patients who 10 years ago would have died in a short period of time are experiencing many years of remission with immunotherapies; some of them might even be cured. This is really revolutionary.

“The issue with prostate cancer is that immunotherapy only seems to work in exceedingly few cases, and we don’t really know why or have strategies to increase response rates.”

Currently, immunotherapy is not approved as a prostate cancer treatment because of very low response rates. Instead, patients with late-stage metastatic prostate cancer are treated with hormonal therapies and chemotherapies, which are only effective for a period of time.

“Realistically, the only way we’ll get to a stage where we can cure some of these men with late-stage metastatic prostate cancer is an immunotherapy that harnesses the body’s immune system,” A/Prof Selth said.

Prostate cancer grows in an ‘immunosuppressive’ environment. This means the cancer cells change their environment to suppress the immune system and avoid being killed.

A/Prof Selth will treat prostate cancer tumours collected from patients with male sex hormones – androgens – and test whether this can sensitise prostate tumours to immunotherapy.

“We’re proposing that this type of hormonal therapy could change the local immune environment in a prostate tumour, so that the immune system could be more likely to kill the tumour cells,” A/Prof Selth said.

This is one of nine projects being undertaken by researchers in the new Freemasons Centre for Male Health and Wellbeing at Flinders University. The Centre’s research is supported through funding from the Masonic Charities Trust and Flinders Foundation.

The Freemasons Centre for Male Health and Wellbeing is an SA and NT research alliance involving Flinders University and Flinders Foundation, Masonic Charities Trust, the South Australian Health and Medical Research Institute, Menzies School of Health Research and the University of Adelaide.

A/Prof Selth is also supported by a Beat Cancer Principal Research Fellowship from Cancer Council SA.

Research category: Prostate Cancer

Project title: Investigating the effects of androgen therapies on the prostate immune system 

Chief and Associate Investigators: A/Prof Luke Selth (Flinders University) (Pictured), Prof Lisa Butler (University of Adelaide), Prof Gary Wittert (University of Adelaide), A/Prof Belinda Parker (Peter MacCallum Cancer Centre), Dr Jianling Xie (Flinders University)