The American Society of Clinical Oncology (ASCO) recently released new prostate cancer guidelines recommending that the androgen blocker Zytiga (abiraterone acetate) or the chemotherapy drug docetaxel be added to androgen deprivation therapy (ADT) for men with advanced prostate cancer who haven’t yet received hormone therapy.
Testosterone and other androgens (male hormones) stimulate prostate tumor growth. Androgen deprivation therapy—often started after surgery—reduces testosterone production. Zytiga, which was approved by the Food and Drug Administration (FDA) in February, stops production of other androgens throughout the body. The LATITUDE and STAMPEDE studies showed that starting Zytiga early along with ADT reduced the risk of death by about 40 percent.
Men who have developed resistance to ADT but whose cancer has not yet spread also have a new option. A week later, the FDA approved Erleada (apalutamide), a medication that interferes with androgen receptor signaling, for men with high-risk prostate cancer that has stopped responding to standard hormone therapy. In the SPARTAN trial, Erleada delayed cancer progression or death by two years. Another study showed that a similar drug, Xtandi (enzalutamide), reduced the risk of metastasis or death by 71 percent.
Some experts favor watchful waiting for men with no visible evidence of metastasis, but high-risk prostate cancer can quickly spread. “These findings suggest there may finally be a treatment that holds real promise for extending their health and their lives,” says Sumanta Kumar Pal, MD, of City of Hope Comprehensive Cancer Center in California.