How immunotherapy may overcome the barriers to treating metastatic prostate cancer

Worldwide, 1.3 million men have prostate cancer resulting in more than 360,000 men dying yearly. Prostate cancer is the second most common cancer around the globe and will impact an estimated 1 in every 7 men during their lifetime.

In the early stages of prostate cancer, when cancer is confined to the prostate gland, survivability is close to 100% over the next five years. Treatment options for early-stage prostate cancer include active surveillance, surgery, radiation, and hormone therapy, depending on various factors. 

However, it’s a different story for men with metastatic prostate cancer. The five-year survival rate drops to less than 30%. In addition, metastatic prostate cancer has always been a challenge to treat. Metastatic means ‘cancer that has spread beyond an organ.” In the case of prostate cancer, cancer has escaped beyond the walnut-sized prostate gland, whose function is to secrete seminal fluid, helping nourish and protect sperm. In most cases, advanced, high-risk, or metastatic prostate cancer almost always spreads to the lymph nodes and the bones. 

Because there is a dramatic difference in survivability rates between early-stage, localized prostate cancer and metastatic prostate cancer, is why researchers are tirelessly looking for more effective treatment for advanced prostate cancer to improve and extend the life of men with this disease. 

The good news of cancer immunotherapy for men with prostate cancer is that it offers the possibility of long-term cancer remission.

Current immunotherapy prostate cancer treatment options 

A promising treatment is emerging for men with metastatic prostate cancer and other types of cancer called immunotherapy. Immunotherapy for prostate cancer works by taking advantage of using the power of a patient’s immune system to fight back cancer cells. 

Various forms of cancer immunotherapy include targeted antibodies, cancer vaccines, adoptive cell transfer, tumor-infecting viruses, cytokines, and adjuvants. The advantage of using cancer immunotherapy for prostate cancer is that it can be used in conjunction with surgery, chemotherapy, radiation, or other targeted treatments improving their effectiveness.

There are three ways using immunotherapy for prostate cancer appears promising:

• Immunotherapy is precise – Immunotherapy makes it possible to target cancer cells without harming healthy cells.
• Immunotherapy is adaptable – Our immune system can continuously adapt so that if a cancerous tumor is sneaky by hiding, the immune system is able to re-evaluate and start a new attack.
• Immunotherapy has a memory – Our immune system can memorize and identify cancer cells enabling it to specifically target and kill cancer cells that return. 

Currently, there are three FDA-approved immunotherapy options for fighting prostate cancer which include the following:

• Cancer vaccine called Sipuleucel-T – This vaccine is used to treat prostate cancer which has spread beyond the gland. A patient’s immune cells are used to compose the vaccine and then stimulated to target the prostatic acid phosphatase protein which is highly expressed in prostate cancers. It has been approved for men with prostate cancer who have few or no symptoms and whose cancer is castration resistant, meaning it has not responded to other treatments used to lower testosterone levels. 
• Immunomodulator called Dostarlimab (Jemperli) – This immunotherapy targets the PD-1/PD-L1 pathway and has been approved for men with advanced prostate cancer that has spread or is unable to be removed by surgery and have a DNA mismatch repair deficiency.
• Immunomodulator called Pembrolizumb (Keytruda) – This immunotherapy targets the PD-1/PD-L1 pathway and is approved for men with advanced prostate cancer with a high microsatellite instability, DNA mismatch repair deficiency, or high tumor mutational burden. It boosts the immune system’s ability to detect and kill tumor cells. 

Besides these three FDA-approved immunotherapy treatments for prostate cancer, there are currently several other immunotherapy options in clinical trials for men with advanced prostate cancer.

Men and their families need to know that immunotherapy for prostate cancer do not always work for every patient. Certain types of immunotherapy have resulted in potentially severe side effects. However, most side effects of immunotherapy men may experience are manageable.

In the meantime, the future for successfully treating metastatic prostate cancer with immunotherapy treatment holds the potential for saving more men’s lives as it becomes more precise, personalized, and more effective than current cancer treatments.  In addition, scientists are working on reducing the side effects of the treatments and controlling prostate cancer in a more efficient and life-extending manner as possible. 

Dr. David Samadi is the Director of Men’s Health and Urologic Oncology at St. Francis Hospital in Long Island. He’s a renowned and highly successful board certified Urologic Oncologist Expert and Robotic Surgeon in New York City, regarded as one of the leading prostate surgeons in the U.S., with a vast expertise in prostate cancer treatment and Robotic-Assisted Laparoscopic Prostatectomy.  Dr. Samadi is a medical contributor to NewsMax TV and is also the author of The Ultimate MANual, Dr. Samadi’s Guide to Men’s Health and Wellness, available online both on Amazon and Barnes & Noble. Visit Dr. Samadi’s websites at robotic oncology and prostate cancer 911.