What Is Castration-Resistant Prostate Cancer?

Medically Reviewed by Sabrina Felson, MD on May 15, 2022
4 min read

Most people with prostate cancer won’t die from it. But it still kills more American men than any type of cancer except lung cancer, because prostate cancer is more common.

Prostate cancer needs testosterone to grow. So treatment aims to cut off the supply of this male sex hormone, most of which is made by the testicles. Blocking male sex hormones is called androgen deprivation therapy (ADT). Androgen is the word for male hormones like testosterone. Most often, hormone therapy involves medications, and it’s referred to as chemical or medical castration because it suppresses your sex hormones.

While much less common, some men opt for surgical castration, in which the testicles are removed. In a recent study of nearly 25,000 men, only about 5% underwent surgical castration. Both types of castration offer similar average survival times of about 2 to 2 1/2 years.

When the cancer keeps growing even though your testosterone production remains low, this is when you are likely to get a diagnosis of castration-resistant prostate cancer (CRPC).

Castration-resistant prostate cancer is an advanced prostate cancer. There is no cure, but new treatments may help you live longer.

CRPC can be metastatic or nonmetastatic.

Metastatic CRPC. This is when the prostate cancer has spread, or metastasized, to other parts of the body, such as the bones and lymph nodes. Standard hormone therapy doesn’t help because the cancer has learned to grow even without being fueled by testosterone. Almost everyone whose prostate cancer has spread will eventually have a castration-resistant form of the disease. They account for most of the deaths from prostate cancer.

Nonmetastatic CRPC. The cancer hasn’t spread and is only found in the prostate. The cancerous growth no longer responds to hormone treatments.

You often may not notice any signs if your CRPC has not spread. Symptoms of metastatic CRPC, on the other hand, may depend on how large the tumor is and whether it has reached the lungs, rectum, and other organs and tissue. You may:

  • Have trouble or pain while peeing
  • See blood in your urine
  • Lose weight
  • Feel tired or weak
  • Have bone aches
  • Feel short of breath

Your doctor has several ways to check if your prostate cancer has become castration-resistant.

Blood test. While you have hormone therapy, your serum testosterone level will measure less than 50 nanograms per deciliter. That should keep your prostate-specific antigen (PSA) level from rising. Your doctor will regularly check your PSA to be sure it remains low. A rising PSA is the primary sign that your prostate cancer has become castration-resistant.

Imaging tests. To see if your cancer has spread to other parts of your body, your doctor will likely order imaging tests, such as:

  • Computed tomography (CT)
  • Magnetic resonance imaging (MRI) scans
  • Bone scans

Treating nonmetastatic CRPC (nmCRPC). If you have CRPC that hasn’t yet spread beyond the prostate, a major goal of treatment will be to delay that spread. Treatment also will aim to help you live longer while allowing you to maintain a normal life.

This can be complex. You'll likely stay on ADT so that your testosterone level stays low. If it’s allowed to rise, that could contribute to the progression of your cancer. During this time, you and your doctor will need to discuss the risks and benefits of treatment. You’ll also need to see how your cancer treatments will interact with medications you take for other health problems you may have.

Because most of those who get prostate cancer are older, other diseases that often come with age are common, especially heart disease. ADT can impact your heart health, which can complicate treatment. It also can up your risk of falls and fractures, affect your cognition, interfere with your ability to have sex, and more.

Treating metastatic prostate cancer (mCRPC). If your CRPC has spread to other parts of your body, such as your bones, there are treatment options available. The primary goals of therapy are to relieve your symptoms and to slow the growth of your cancer. You’ll stay on ADT to control any prostate cancer cells that may still respond to it. Otherwise, your testosterone levels may rise and cause tumor growth.

Other treatments you may receive include:

In clinical trials, the newest drugs for nmCRPC can delay the spread of prostate cancer for an average of up to nearly 3 1/2 years. People who took these drugs lived up to an average of 14 months longer than those who took a placebo.

The average person whose CRPC has spread will live less than 2 years with mCRPC. However, new treatments are starting to lengthen that amount of time, so there is hope that people with this condition will be able to live longer.

Non-Hispanic Black people are much more likely to get prostate cancer than those of any other race or ethnicity. Prostate cancer rates are lowest among non-Hispanic Asian Americans. Black people also are more likely than non-Black people to be diagnosed with advanced prostate cancer. But in treatment, Black people have at least similar outcomes compared to non-Black people. Researchers don’t fully understand the reasons for these differences.