The idea behind castration treatment is to deprive the body of the hormones that feed the cancer cells. Until recently, for patients whose cancer had returned after medical castration the only option was chemotherapy.

“A castration causes the cancer to regress and it gives patients pain relief and remission from their disease for several years,” explained Dr. Fred Saad, who is Professor and Chief of Urology and Director of G-U Oncology at the University of Montreal Hospital Centers.

“Unfortunately, the majority of patients, over a period of two or three years, will become resistant to the hormone therapy.” In other words, the cancer will progress even with the absence of androgens or testosterone in the circulation.

“Unfortunately, the majority of patients, over a period of two or three years, will become resistant to the hormone therapy.”

Important breakthroughs

But, in the past two years, there have been significant advances in research, and new therapeutic methods have been developed to treat men with CRPC.

One discovery is of an agent that is able to shut down secretion and production of testosterone in the testes, the tumour itself and in the adrenal gland. Testing of this treatment led to striking results in prolonging life and improving the quality of life for patients that had failed both castration therapy and chemotherapy.  

Recently, Health Canada also endorsed this treatment for men with metastatic CRPC in the pre-chemotherapy setting — a great advance for those unable or willing to pursue chemotherapy.

Research has also led to another discovery for the treatment of CRPC, and this one works in a different way. “It’s a medication that works to block the receptors of the testosterone instead of working to stop its production,” explained Urologist, Dr. Andrew Feifer.

It works in six different ways to block the androgen receptor function, which in turn prevents the cancer cells from getting the fuel — testosterone — that they need to progress. These extraordinary new treatments are extremely easy to take, they have minimal side effects, and so far, there have been very few patients who are unable to tolerate them.

Of patients who have CRPC, 80 to 90 percent will have bone metastases, a condition that, if left untreated, can lead to a pathological bone fracture. “This can cause pain to such a degree that a patient needs radiation to dull the pain and surgery to stabilize a bone at imminent risk of giving way,” explained Dr. Bobby Shayegan Associate Professor of Urology at St. Joseph’s Healthcare Institute.

Until 2004 there was no treatment for bone metastases, but in that year a new agent was discovered that, when administered, resulted in men with CRPC having substantially less chance of developing bone problems. Then in 2011, another breakthrough treatment was discovered.

“This agent is even more effective than the earlier treatment,” explained Dr. Shayegan.  “There’s an 18 percent reduction in complications of bone metastases in patients taking the new agent compared with the one from 2004. This agent is more effective and convenient to administer.”

"There is a growing consensus amongst experts that a slightly more diligent approach to screening long-term patients could prolong and improve the lives of even more men that are suffering with prostate cancer."

Continued search for improvements

How to most effectively administer these new medications is outlined in a new set of guidelines developed by the Canadian Urological Association (CUA) that aim to standardize best practices amongst Canadian urologists and urologic oncologists.

“They act a bit like a white paper,” said Dr. Feifer. “Helping and guiding practitioners to the best treatment options for their patients.”

All of the recent discoveries offer new hope to patients with advanced stage prostate cancer. The subject of how often long-term prostate cancer patients should be screened for metastases, if they have no symptoms, has been a contentious one. But, with the new products that are available, there is a growing consensus amongst experts that a slightly more diligent approach to screening long-term patients could prolong and improve the lives of even more men that are suffering with prostate cancer.