New prostate cancer treatment improves survival rate in men with advanced disease

Metastatic, castration-resistant prostate cancer kills approximately 500 men every year in B.C.

A phase III clinical trial has shown a new way of treating prostate cancer, successfully improving the overall survival rate in men with metastatic castration-resistant prostate cancer (mCRPC). Prostate cancer is the most common cancer among Canadian men and is the third most common cause of cancer death. Metastatic castration-resistant prostate cancer is an advanced and deadly form of prostate cancer.

“There is a critical need to improve outcomes for patients with the most advanced forms of prostate cancer,” says Dr. Kim Nguyen Chi, medical oncologist at BC Cancer and co-author of the study. “Patients with mCRPC in this study have an average survival rate of less than one year with our current treatments. These data show that this new treatment can significantly prolong survival and delay the spread of the disease.”

The study, recently published in the New England Journal of Medicine, examined the effects of 177Lu-PSMA-617, a radioligand therapy, when combined with the current standard of care compared to the current standard of care alone. The results showed a 38 per cent increase in overall survival rates in patients who received the new form of treatment.

“I have patients who are still alive and doing well,” says Chi. “I would not have expected this outcome had they not participated in this trial. Follow up scans showed that their cancers had regressed and had remained so over time even at their advanced stage. Overall the treatment is well tolerated and quality of life was not significantly impacted by the treatment.”

Seventy-eight year old David was diagnosed with prostate cancer in 2015. His original oncologist suspected he may have anywhere from three to five years remaining. “I was really down about it,” said David, “but I believe in the power of positive thinking so I tried to remain optimistic.”

When his cancer spread he began seeing Chi and was enrolled in the clinical trial. “It has now been six years since my original diagnosis. The cancer isn’t gone, but I’m doing much better. I try to eat well and stay active these days. My wife and I love to travel and we try to do that as much as we can.” David is now looking forward to celebrating his 53rd wedding anniversary next spring.

Radioligand therapy is a form of precision medicine that delivers targeted radiation specifically to all tumour locations in the body.  In essence, the treatment acts like a guided missile programmed to only target cancer tumours and leave healthy, normal cells intact. A radioactive isotope, in this case lutetium-177, is combined with a compound that is known to bind specifically to prostate cancer cells (PSMA-617), causing damage to the tumour’s DNA and cell death.

Currently, access to 177Lu-PSMA-617 is limited to patients participating in clinical trials and studies co-led by Dr. Chi, are looking at outcomes of treating prostate cancer patients with 177Lu-PSMA-617 earlier in their disease progression are ongoing. Chi and colleagues are hoping to have an access program in B.C. to start treating patients as soon as possible.

“I volunteered to participate in this trial after hearing about the success of the previous trial,” says Chris, who will be participating in the next version of Dr. Chi’s 177Lu-PSMA-617 clinical trial. “I learned my prostate cancer had spread four months ago, so the opportunity to participate in this trial means a lot to me. I’m very excited about the prospects not only for myself, but for what the outcomes could mean for the many other men dealing with advanced prostate cancer.”

 

Quick facts:

  • Prostate cancer accounts for 12 per cent of all cancer diagnoses in men in B.C.
  • One in 9 men is expected to develop prostate cancer during their lifetime
  • This year, an estimated 3,630 men in B.C. will be diagnosed with prostate cancer

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