Researchers in the United Kingdom have announced what they believe is the most promising new treatment for prostate cancer in 15 years. Known as PSMA (prostate specific membrane antigen) radiotherapy, it could extend the lives of many men who are living with advanced prostate cancer who have run out of treatment options.
This “game changing” treatment utilizes high-tech molecules to track down tumors located anywhere in the body. Once located, the tumors are treated with a blast of radioactivity.
Word of the breakthrough prostate cancer treatment was presented at the American Society of Clinical Oncology Congress in Chicago. Currently the treatment is being tested on 200 men in ten facilities around the world.
As of this writing, the PSMA radiotherapy was made available privately in Britain for the first time to two men. The cost of therapy, which involves between two and six sessions given every six weeks, is 12,000 to 13,000 pounds per treatment.
According to Hans Schaupp, one of the men who was treated with the breakthrough prostate cancer treatment, “I feel absolutely perfect. No side effects, nothing.”
Australian oncologist Arun Azad, associate professor at the Peter Mac Cancer Centre in Melbourne and who is part of the multicenter trial, explained that “If the results are positive, it really will change the landscape of how we treat prostate cancer.” He estimates that approximately 50 percent of the 10,000 men who have diagnosed advanced prostate cancer in Britain each year could benefit from PSMA radiotherapy.
If all goes well, in the future the treatment might be earmarked for men who have earlier stages of prostate cancer. Such a move would open up the door for many more men who are living with the disease.
How the breakthrough prostate cancer treatment works
Traditional external radiation is commonly used for men with prostate cancer, but only for early, low-risk disease, which has not spread beyond the gland. Advanced prostate cancer involves cancer that has spread into other parts of the body, which makes it impossible to treat using external radiation. Therefore, using a targeted radiotherapy is a viable alternative.
PSMA radiotherapy is known as a “seek and destroy” approach, and here’s why. Clinicians inject a “seeking” molecule called PSMA-617 into the bloodstream. Its job is to seek out and attach itself to a protein on the surface of prostate cancer cells called PSMA.
Once the PSMA-617 is firmly attached, it releases the “destroy” part of the treatment: a nuclear isotope called Lutetium-177. This radiotherapy (also known as LuPSMA) emits beta particles that travel a mere 1 millimeter, which ensures that only the prostate cancer cells are damaged and not any of the healthy tissue that surrounds them. LuPSMA also releases low levels of gamma rays that can be seen using nuclear imaging.
In 2017, a review of the literature on this new treatment for prostate cancer was published in the Journal of Medical Radiation Sciences. The authors considered all of the then-currently published trials and stated that PSMA delivering lutetium-177 “almost certainly has an important future role in the treatment of prostate cancer.” They pointed out its low toxicity profile and that it was well tolerated by men who had end-stage metastatic prostate cancer.
In Australia, 50 men were treated with the new therapy in a pilot study. The LuPSMA technique extended the life expectancy of the men from nine months to an average of 13.3 months. However, 20 percent of the patients were still alive after 33 months.
Trials of LuPSMA radiotherapy are ongoing throughout the world. If results continue to be positive, it could eventually join the ranks of other treatments for metastatic castration-resistant prostate cancer.
Emmett L et al. Lutetium-177 PSMA radionuclide therapy for men with prostate cancer: a review of the current literature and discussion of practical aspects of therapy. Journal of Medical Radiation Sciences 2017 Mar; 64(1): 52-60
Goodman A. Radioligand therapy achieves responses in metastatic prostate cancer. ASCO Post 2019 Mar 10
Spencer B. Prostate cancer breakthrough: new treatment to ‘seek and destroy’ tumours could extend lives of thousands of patients. Daily Mail 2019 Jun 3