The term metastatic castration-resistant prostate cancer (mCRPC) refers to a cancer that has spread (metastasized) beyond your prostate gland and for which hormone therapy is no longer effective in stopping or slowing the progression of the cancer. In the past, this was known as hormone-refractory and androgen-independent prostate cancer, but these terms are rarely used now.
This type of prostate cancer can be very hard to treat, even when doctors catch it early. “This cancer escapes control,” says Michael S. Cookson, MD, a urologic oncologist, as well as a professor of and the chair of urology at the University of Oklahoma College of Medicine in Oklahoma City. “[MCRPC is] like a car that keeps moving, even though you’re pushing on the brakes in the form of hormone therapy.”
It’s common for hormone therapy, known as androgen deprivation therapy (ADT) or “chemical castration,” to stop working after a few years. The goal of the therapy is to block testosterone from stimulating the cancer to keep growing. The term “castration resistant” refers to a cancer that is no longer responding to ADT.
According to some research, mCRPC accounts for about 1 to 2 percent of all prostate cancer cases worldwide.
But it’s hard to pin down exact numbers, partly because newer, more sensitive imaging technologies are now able to find smaller cancer cells beyond the prostate gland that couldn’t be found before. So the same cancer that would have been considered nonmetastatic before is considered metastatic today, explains Scott T. Tagawa, MD, a medical oncologist at NewYork-Presbyterian Hospital and professor of urology at Weill Cornell Medicine in New York City.
“Our scans are getting better,” says Dr. Tagawa. “When we just had X-rays, we missed small things. Then we got MRIs and CT scans, and we still missed some things. But now that we have more specific PET scans, we can see things we couldn’t see before.” And finding cancer sooner means treating it sooner.