TRIAL UPDATE: 8 July 2025

The TROG 19.06 DECREASE trial into advanced prostate cancer has reached a significant milestone with recruitment of the final participant in late June, bringing total recruitment to 70 participants.

Congratulations to trial chairs Prof Shankar Siva and Prof Arun Azad and all involved in the trial, which recruited its first participant in mid-2021, and has since randomised a total of 70 participants from 15 sites across Australia plus one site in Singapore.

In the era of PET imaging, many sites of disease that are not visible on conventional imaging are found on PSMA (prostate specific membrane antigen) PET scans.

The DECREASE trial involves men with castration-resistant prostate cancer (not treatable with testosterone-lowering therapy) who have no evidence of metastases on conventional imaging, however, they have detectable disease on PSMA-PET scans.

Entitled DarolutamidE + Consolidation RadiothErapy in Advanced proStatE cancer detected by PSMA, DECREASE is investigating whether adding radiation therapy to the currently indicated treatment of hormone therapy with the androgen receptor inhibitor Darolutamide can improve outcomes for these patients by controlling further spread of prostate cancer.

TROG provides trial coordination and is the primary sponsor of the study, which is funded by Bayer. TROG’s role includes conducting comprehensive radiation therapy quality assurance (RTQA) for the trial, including pre-trial site credentialling and centralised on-trial individual case reviews. The TROG RTQA team is also leading the centralised collection and storage of PSMA-PET imaging for the trial (at screening, 12 weeks and progression).

“I’m very grateful to all the investigators for their tireless efforts, as well as patients and their families for participating in the trial and thanks to my co-PI Arun Azad,” Prof Siva said.

• Find out more about the TROG 19.06 DECREASE trial