Ontario researchers’ work helps improve prostate cancer treatment

By Brian Williams, Local Journalism Initiative Reporter, London Free Press

A multi-centre study whose leads include London-based researchers has found a new imaging solution that can more effectively detect the recurrence of prostate cancer and is linked to improved survival rates.

Led by London Health Sciences Centre Research Institute (LHSCRI), Lawson Research Institute of St. Joseph’s Health Care London and University Health Network (UHN), the study – carried out over seven years and published in the Journal of Nuclear Medicine – has found a novel imaging solution, called prostate-specific membrane antigen (PSMA) positron emission tomography (PET) scanning.

The scan can detect prostate cancer in “closer to three quarters of men” where the “pickup rate with conventional scans” was between 10 per cent and 20 per cent, said Glenn Bauman, a scientist at LHSCRI and radiation oncologist.

“(PET scanning) has been used quite often in the past, but there were not prostate-specific imaging agents for use with PET scanners that were available,” Bauman said in an interview on Tuesday. “PSMA PET is really a targeted scan looking for prostate cancer cells themselves.”

Bauman said a radioactive molecule designed to target a protein in prostate cancer cells is injected into the bloodstream before the PSMA PET scan. The study revealed that the molecule is effective in binding to prostate cancer cells and helps to detect recurring prostate cancer earlier and more effectively than standard imaging methods, such as conventional bone scans and CT scans.

“Using the (PSMA) PET scan, you can see where it localizes, and this allows us to see much smaller amounts of prostate cancer in lymph nodes or bone or elsewhere,” Bauman said, noting the new technique provides doctors the necessary information to determine the best treatment and target the cancer effectively.

Nearly 90 per cent of men with cancer detected by a PSMA PET scan had a change in the management of their recurring prostate cancer, LHSC officials said in a statement, adding patients who had their treatments modified had a better overall survival rate than others who received standard imaging.

Ur Metser, division head of molecular imaging at UHN and clinician scientist at UHN’s Princess Margaret Cancer Centre, said in a statement the PSMA PET scan study results were encouraging, noting the “imaging approach is already changing cancer care” for patients.

“Our study showed that PET scans using this technique led to more personalized treatment decisions and those changes are linked to longer survival. That’s a meaningful step forward for patients and their care teams,” he said.

According to the Canadian Cancer Society’s website, prostate cancer is the most common cancer among men, excluding non-melanoma skin cancers, and is the third leading cause of death from cancer in Canadian men.

Bauman and his colleagues from Lawson and LHSCRI were the first in Canada to image a patient using PSMA PET imaging in 2016, and the study has since enrolled thousands of men across six Ontario hospitals through Ontario Health – Cancer Care Ontario funding, and the imaging technique is funded as a standard of care test for men with advanced prostate cancer, LHSC’s news release said.

“I think it has a huge impact across the whole spectrum of men with prostate cancer,” Bauman said.