How the PSMA PET scan worksImage by: Movember
3 March 2022

New scan predicts how men respond to prostate cancer therapy

3 minutes read time

A new type of imaging scan – partly funded by Movember – could soon be used as a tool to help clinicians predict how well men with advanced prostate cancer are likely to respond to cutting-edge radiation therapy.

An in-depth analysis of data from the TheraP trial has shown that men who had high levels of PSMA (Prostate Specific Membrane Antigen) - a protein found on the surface of prostate cancer cells - were highly likely to respond successfully to Lu-PSMA radionuclide therapy.

Lu-PSMA is a unique therapy that works by ‘mapping’ the prostate cancer cells using a PET scan, and then treating them with a radioactive substance called Lutetium-177.

Unlike conventional chemotherapy, Lu-PSMA therapy can destroy cancer cells, while minimising damage to surrounding tissue.

" We are very grateful to our Mo community whose generous support allows us to fund cutting-edge research which makes a real difference to the lives of the men we serve. "

Study chair Professor Michael Hofman of the Peter MacCallum Cancer Centre in Melbourne, who tested the treatment in a trial of 200 men, said: “On average, the men on the trial did better with Lu-PSMA therapy compared with cabazitaxel (a type of chemotherapy).

“However, the odds of responding to Lu-PSMA vs cabazitaxel were 12 times higher if the men had high levels of PSMA expression, compared with men who had low PSMA expression. This demonstrates that PSMA PET scans are a very reliable and highly effective biomarker (test) for response to Lu-PSMA therapy.”

He added: “We now have a whole range of treatment options for men with metastatic prostate cancer from cabazitaxel to olaparib, pembrolizumab and now Lu-PSMA. Using PSMA PET scans as imaging biomarkers is going to be critical in the move towards more personalised care and enable clinicians to select the best treatment for their patients.”

Dr Sarah Hsiao, Director of Biomedical Research at Movember, said:

“Deciding which treatment to give can be a very complex decision. If the use of PSMA PET scans as predictive biomarkers for Lu-PSMA can be validated, this would give clinicians greater certainty and confidence that they have selected the right for the right man in the fight against advanced prostate cancer.”

“We are very grateful to our Mo community whose generous support allows us to fund cutting-edge research which makes a real difference to the lives of the men we serve."

The analysis also showed that men who had a high volume of disease on an FDG PET scan had a worse prognosis, regardless of whether they had chemotherapy or Lu-PSMA therapy.

The findings were presented at the American Society of Clinical Oncology Genitourinary Cancers Symposium 2022 meeting in San Francisco, California.

TheraP (ANZUP 1603) is a partnership between ANZUP Cancer Trials Group and the Prostate Cancer Foundation of Australia (PCFA) with support from the Australian Nuclear Science and Technology Organisation (ANSTO), the Australasian Radiopharmaceutical Trials Network (ARTnet), Endocyte Inc, a Novartis company, It’s a Bloke Thing, Movember and CAN4CANCER and The University of Sydney NHMRC Clinical Trials Centre providing central study coordination.