PSMA PET/CT imaging drastically reduces the need for prostate biopsies
PSMA (prostate-specific membrane antigen) PET/CT imaging can drastically reduce the need for prostate biopsies, according to new evidence.
Researchers recently presented early findings from the PRIMARY2 clinical trial at the European Association of Urology Congress in London on March 13. The Phase 3 trial has recruited 660 people who are at higher risk of prostate cancer but received normal MRI results.
Participants in the control arm underwent prostate biopsies, while those in the study’s experimental wing had PSMA PET/CT scanning. About 44% of those who underwent biopsies did not end up having prostate cancer versus 22% in the experimental arm.
Meanwhile, about 32% of those in the control arm had low-risk or slow-growing cancer that required no treatment versus 14% in the PET/CT group.
“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,” James Buteau, MD, a nuclear medicine specialist at the Peter MacCallum Cancer Center, Melbourne, Australia, said in a statement March 13. “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.”
Patients suspected of having prostate cancer typically undergo an MRI to look for abnormal areas of the organ. If the results are suspicious or inconclusive, they then receive a biopsy, taking a small sample of tissue to look for cancer cells. Experts note that the procedure is routine but invasive, causing discomfort and potential worry for patients awaiting results.
PRIMARY2 recruited participants who had received a PI-RADS (Prostate Imaging Reporting and Data System) score of 2 or 3, signaling low or intermediate risk of cancer. Subjects also held other prostate cancer risk factors such as a rising PSA (prostate-specific antigen) or strong family history of the disease.
After a suspicious MRI, patients were randomly assigned to either undergo a standard biopsy or PSMA PET/CT scan. The nuclear exam helped to pinpoint those who either didn’t have cancer or a form of the disease that was so low risk that it would likely never cause harm. These individuals skipped the biopsy while those with positive PET/CT scans had one, which cut the number of such tests in half, without missing any harmful cancer cases.
Dr. Buteau and colleagues note that PSMA PET/CT is becoming increasingly accessible in the U.K. and Europe, primarily for high-risk or recurrent prostate cancer. Cost and availability, however, have limited its widespread use. The trial, sponsored by the MacCallum Cancer Center, is expected to continue, with further results to be presented in the future.
Those involved believe this is one of the largest studies to explore whether PSMA PET/CT can improve cancer diagnoses while reducing biopsies. They contend that their early findings support the consideration of the modality in the diagnostic work-up of appropriately selected patients.
“Getting told you have a risk of prostate cancer is a huge cause of anxiety and concern,” Louise Emmett, MD, study co-lead and director of theranostics and nuclear medicine at St. Vincent's Hospital, Sydney, said in the announcement. “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.”
Marty Stempniak has covered healthcare since 2012, with his byline appearing in the American Hospital Association's member magazine, Modern Healthcare and McKnight's. Prior to that, he wrote about village government and local business for his hometown newspaper in Oak Park, Illinois. He won a Peter Lisagor and Gold EXCEL awards in 2017 for his coverage of the opioid epidemic.