Dr. Andrew Loblaw
Full Professor, Radiation Oncology, Sunnybrook Health Sciences Centre
Cure Prostate Cancer Canada supports trials testing shorter, more precise treatments to improve cancer control and protect patients’ quality of life.
Prostate cancer is the second most commonly diagnosed cancer in men after skin cancer. Over the past 25 years, prostate cancer cure rates have improved, and treatment-related side effects have declined.
Men who have just learned they have prostate cancer should speak with two doctors. A urologist can explain surgery. A radiation oncologist can explain treatments that do not use surgery. Consulting with both can help patients compare their treatment options and choose what’s best for them.
Radiation treatment has improved significantly since I began practising in 2000. At that time, treatment did not work for about half of men with a common type of prostate cancer. It could also require 40 visits over eight weeks.
High-quality clinical trials now show that a more precise type of radiation can be given safely in five visits. It’s called stereotactic body radiotherapy, or SBRT. After 10 years, 95 per cent of men with medium-risk prostate cancer are still free of cancer. Very few patients have serious side effects. SBRT has also been shown to work better than brachytherapy, a form of internal radiation sometimes called “seed therapy.”
Being cured without compromise
The chance of losing bladder control after radiation is almost zero. Most men who have good sexual function before treatment still have it afterward. Protecting quality of life is important because more men are being diagnosed at younger ages.
Research in Canada and other countries suggests that a more precise form of SBRT, given in only two visits, may cause even fewer bowel and sexual side effects. Studies are now testing this idea by placing patients into different treatment groups by chance.
Cure Prostate Cancer Canada (CPCC) funds important research and clinical trials aimed at improving cure rates while reducing side effects.
Studies that are improving prostate cancer care
Here are some studies supported by CPCC, along with promising research it hopes to support in the future.
PACE-B: Showing that five SBRT treatments work
PACE-B was a large study conducted in several countries. It compared standard radiation, given in 20 or 39 visits, with SBRT, given in five visits. The study included men whose prostate cancer had not spread and was at low or medium risk.
The results were published in The New England Journal of Medicine. They showed that five SBRT treatments controlled the cancer as well as standard radiation. This helped make SBRT a common treatment choice around the world.
Using SBRT for higher-risk cancer
CPCC has supported two studies of SBRT for men with higher-risk prostate cancer:
- 5STAR-PC: This study tests five SBRT treatments for the prostate and nearby lymph nodes. MRI scans help doctors give extra radiation to the main tumour.
- ASCENDE-SBRT (CCTG PR24): This large study in several countries compares five SBRT treatments with the standard treatment of 24 doses. The standard treatment uses radiation from outside the body and an extra dose (brachytherapy or seed therapy) placed inside the prostate. All patients also receive hormone treatment for a length of time based on their level of risk.
ASCENDE-SBRT is currently enrolling patients at many centres across Canada. The study will test whether a shorter and more precise treatment can control cancer while making treatment easier for patients with higher-risk disease.
DIRECT: Treating cancer that has spread
Radiation may also help some people with prostate cancer that has spread to other parts of the body. This is called metastatic or stage 4 cancer. In the CPCC-supported DIRECT study, all patients receive hormone treatment for eight to nine months. They also receive SBRT for cancer spots seen on scans. Patients are then placed by chance into two groups. One group receives a newer hormone drug, and the other does not. The study will test whether the extra drug keeps the cancer under control for longer.
I’ve treated patients whose cancer had spread and who are still alive, doing well, and not on treatment more than 10 years later. Stories like this show why we must keep testing new treatments in carefully designed studies.
PACE Post-Op: A possible future study
CPCC also plans to support PACE Post-Op, a study led by researchers in the United Kingdom. It’s for patients who need radiation after prostate surgery because the cancer may have returned. The study will compare SBRT after surgery with standard radiation (20 to 33 treatments).
We hope to open the study in Canada in 2027. Funding will help launch the study at multiple centres across Canada and enrol the patients needed to answer this important question.
Why donations matter
Groups such as CPCC help improve prostate cancer care by supporting studies that:
- Give patients access to new treatments before they become available as a standard;
- Test whether treatment can be shorter, more exact, and easier for patients;
- Improve cancer control while protecting quality of life.
When donors support this research, they help improve care and reduce the side effects of prostate cancer treatment.
Visit cureprostatecancer.ca to learn more and support this work.