Scan that makes prostate cancer cells glow could cut need for biopsies

(Press-News.org) An imaging test could safely halve the number of people who need a biopsy for suspected prostate cancer following inconclusive or reassuring results from an MRI scan, new research has found.

Findings from the PRIMARY2 trial are presented today [Friday 13 March 2026] at the European Association of Urology Congress in London (EAU26).

The PSMA PET/CT scan identifies more aggressive prostate cancer cells, which are potentially harmful and may need treatment. It does this with a molecule that binds to prostate cancer cells and causes them to ‘glow’, appearing as bright spots in the scanning image. This could also help reduce the risk of overdiagnosis by determining which cancers are low-risk and will never cause harm, the study says.

People with suspected prostate cancer usually have an MRI scan to look for abnormal areas of the prostate. If MRI results are suspicious or inconclusive, patients undergo a biopsy that takes small pieces of prostate tissue and looks for cancer cells. This is a routine but invasive procedure that can be uncomfortable and sometimes worrying for patients and is associated with side effects.

The PRIMARY2 trial recruited people at higher risk of prostate cancer, such as a strong family history, who had a normal result on their MRI. These people often go ahead with prostate biopsy. They were randomly assigned to have either a standard biopsy or a PSMA PET/CT scan.

PRIMARY2 found that PSMA PET/CT scanning could identify people who either did not have cancer, or whose cancer was so low-risk or slow-growing it would likely never cause harm. These people did not need a biopsy. Meanwhile, people with a positive PSMA PET/CT scan result had a biopsy. This approach halved the number of people who needed a biopsy, without missing any harmful cancers.

For patients who still needed a biopsy, their scan results ensured the procedure was targeted to the suspicious areas identified in the test to minimise complications and improve accuracy.

These are the first results released from PRIMARY2, which will follow these 660 patients for two years. PRIMARY2 is an Australia-wide phase III clinical trial, led from Peter MacCallum Cancer Center in Melbourne and St Vincent’s Hospital in Sydney. PSMA PET/CT scanning is becoming increasingly accessible in the UK and Europe, primarily for diagnosing high-risk or recurrent prostate cancer, although cost and availability remain limitations to widespread use. It is widely available in Australia.

Dr James Buteau, a nuclear medicine physician at Peter MacCallum Cancer Centre, is presenting the research at EAU26. He said: “PSMA PET/CT scanning makes prostate cancer cells light up in a remarkable way, particularly in more aggressive cancers. It’s rare to see such strong imaging that could be so powerful in the clinic. Incorporating this testing into clinical care could help to address the major challenge of prostate cancer overdiagnosis, which leads to at best unnecessary and at worst harmful treatment for cancers that would never cause any harm.”

Professor Louise Emmett, Director of Theranostics and Nuclear Medicine at St Vincent's Hospital co-led the study with Professor Michael Hofman from Peter MacCallum Cancer Centre. She said: “Getting told you have a risk of prostate cancer is a huge cause of anxiety and concern. Our findings show that PSMA PET/CT after MRI offers a 'belt and braces' approach that can determine which people have a clinically significant cancer, and which people are at low risk and don’t need a biopsy or further testing. PRIMARY2 is the largest of a series of studies undertaken by this group, exploring whether PSMA PET/CT scanning could improve prostate cancer diagnosis and reduce unnecessary biopsies for patients.”

Professor Dr Derya Tilki is a member of the EAU Scientific Congress Office and a senior consultant urologist at Martini-Klinik Prostate Cancer Center, Germany. She said: “This well-conducted trial shows that incorporating PSMA PET/CT in men with low or intermediate risk lesions – defined by MRI as PI-RADS 2 or 3 – significantly reduced the number of unnecessary biopsies and the diagnosis of clinically insignificant prostate cancer. Importantly, this didn’t compromise the detection of clinically significant disease. These results support consideration of PSMA PET/CT in the diagnostic work-up of appropriately selected patients. I congratulate the investigators on their study.”

END