When prostate cancer progresses, a clearer view can make all the difference
A new diagnostic advance can pinpoint where the cancer has spread
This year, an estimated 24,600 Canadian men will be diagnosed with prostate cancer.
For most men, the journey begins in the family doctor’s office. David, who is pursuing his love for music after a successful professional career, learned of his diagnosis following routine testing at his annual physical. “It was totally out of the blue. I had no symptoms at all.”
Though prostate cancer often grows very slowly, it is the most commonly diagnosed cancer among men in Canada and the third deadliest.
Symptoms of prostate cancer
Prostate cancer has few symptoms in its earliest stages (frequent urination—especially at night, straining to urinate and weak flow, are among the signs that should be discussed with a doctor). The first indicator doctors will look for is elevated levels of PSA, or prostate-specific antigen in the blood, a biomarker used for many years to detect prostate cancer. Higher-than-expected PSA levels are a sign that further investigation is needed.
“If someone is diagnosed with prostate cancer, there are two scenarios,” says Dr. Urban Emmenegger, medical oncologist in the Odette Cancer Centre at Sunnybrook Health Sciences Centre in Toronto, a centre of excellence in the treatment of prostate cancer. “Around 90 per cent of patients have localized cancer at diagnosis, which means the cancer is confined to the prostate gland.”
For those individuals, the prognosis is good. When prostate cancer is localized, the five-year survival rate is almost 100 per cent. “Patients in this group usually undergo surgery, radiation therapy or a program called active surveillance, which, in essence, is repeating PSA readings from time to time and having repeat biopsies,” says Emmenegger.
For those whose cancer has spread, or metastasized, a clear view of the cancer is everything. The more doctors can understand how prostate cancer cells are moving through the body, the better they can make decisions that may improve patients’ prognosis and quality of life. “The problem is, sometimes it’s not so easy to know whether the cancer has already spread,” Emmenegger says.
In David’s case, his PSA numbers were “off the charts” and after a battery of tests, he was told his cancer had metastasized to other parts of his body.
A new prostate cancer biomarker
Fortunately, a new biomarker is giving David’s care team a clearer idea of how his cancer is progressing and where it has spread in his body.
The biomarker is called PSMA, and it is pinpointed with a PSMA PET scan that uses a radioactive imaging agent and a PET scan to identify the location of prostate cancer cells in the body.
“PSMA stands for prostate specific membrane antigen,” Emmenegger explains. “This is one of the most specific proteins expressed at the surface of prostate cancer cells in most men. Using a PSMA PET scan allows us to visualize where the cancer cells are and, to a certain extent, tells us how many cancer cells are in a certain place. Not yet widely available, PSMA PET scans are a more sensitive diagnostic tool than conventional scans, enabling more informed decisions on management of the cancer.”
For David, simply knowing that his doctors have better tools is a comfort. “If there’s a way of seeing the cancer clearer, sharper and sooner, for me, that’s a positive. Now that I’m back into music, my plan is to play for a long time.”