It isn’t often that information on a “game-changing” treatment is published on four cancer websites. But such is the case herein from the National Institutes of Health MedLinePlus, Prostate Cancer Foundation, the June 12 issue of Prostate Cancer News Today and Reuters Health News.
If you have just been diagnosed with metastatic prostate cancer and your doctor wants to start you on hormone (androgen) deprivation therapy (ADT, such as Lupron), which shuts off the supply of testosterone and other male hormones, ask for abiraterone (Zytiga®) as well. It could extend your life for years.
About 3% of the 161,000 new cases of prostate cancer diagnosed annually are metastatic where the cancer has spread beyond the original tumor. These hormone-naive men (who are just starting ADT) are often treated with a combination of the chemotherapy drug docetaxel (taxotere®) and hormone therapy. According to two recent studies (LATITUDE and STAMPEDE) presented at the 2017 meeting of the American Societyof Clinical Oncology (ASCO), chemotherapy with its undesirable side effects may now be replaced by the FDA-approved anti-testosterone pill abiraterone acetate (Zytiga®) in addition to prednisone. The studies will shortly be published in the New England Journal of Medicine. The two studies found that abiraterone lowered patients’ risk of death by nearly 40 percent when added to standard androgen deprivation therapy and prednisone. It also appeared to more than double the average time it took for a man’s prostate cancer to progress, one of the studies reports, extending the average time of progression from 14.8 months to 33 months. It also lowered the risk of the cancer getting worse by 53 percent. Researchers state that this may represent one of the biggest survival gains ever reported in a trial in adults with solid tumor and could change then standard clinical practice overnight. For further details, see the following link to the June 5th report from MedLinePlus published by the U.S. National Library of Medicine.
Testosterone fuels prostate cancer growth, so doctors use androgen deprivation (hormonal) therapy (ADT) to prevent the testicles from producing the male hormone. However, ADT drugs do not prevent the adrenal glands and prostate cancer cells from continuing to produce small amounts of testosterone. Abiraterone, a pill taken once daily, blocks an enzyme that converts other hormones to testosterone, essentially halting production of testosterone throughout the body. The U.S. Food and Drug Administration previously approved abiraterone for patients with metastatic prostate cancer that didn’t respond to regular androgen deprivation hormonal therapy.
One of the researchers stated “what’s dramatic is how much better abiraterone works when it’s given earlier. I have never seen a treatment where you could, five years later, see no progression in some men. There are some extreme responders who get a very significant remission. It may be that abiraterone does not just stop cancer from proliferating, but it also stops, or significantly delays, cancer from mutating and becoming more resistant to treatment. The side effects of abiraterone are minimal, if you take your prednisone.” (Low-dose prednisone is necessary with abiraterone to help the adrenal gland make sufficient amounts of cortisol.) Unfortunately, most insurance companies may not immediately realize that this is going to be the new standard of care. They may not want to pay for abiraterone, and that’s a problem, because the drug, Zytiga®, made by Janssen, is not cheap. It costs $9,000 a month; however, a generic form of abiraterone is expected to come on the market within the next two years.