Stage 4 Metastatic Prostate Cancer

July 1, 2024

This page was reviewed under our medical and editorial policy by Tanya Barauskas Dorff, M.D., professor, Department of Medical Oncology & Therapeutics Research, City of Hope^® Cancer Center Duarte

The prostate is a gland in the male reproductive system that sits just below the bladder and wraps around the urethra (the tube that empties urine from the bladder). Prostate cancer is diagnosed when cancerous cells form within the gland.

The cancer cells may stay within the prostate, or they may spread to other areas. Most prostate cancers are diagnosed before they have spread much beyond the prostate. About 8% of newly diagnosed prostate cancers have spread to distant lymph nodes or organs, also known as Stage 4 prostate cancer or metastatic prostate cancer.

What Is Stage 4 Prostate Cancer?

Doctors classify cancers into stages based on how large the primary tumor is and how far the cancer has spread at the time of diagnosis. This helps them understand how advanced the disease is, how the patient is likely to respond to treatment and which treatment options may be appropriate.

Prostate cancer is grouped into four stages (1-4) using the American Joint Committee on Cancer’s TNM system. T stands for tumor, N stands for nodes, and M stands for metastasis (spread).

Stage 4 is the most advanced stage, meaning cancer cells have spread beyond the prostate and into other areas of the body. Stage 4 prostate cancer cells may also be any grade, from 1 to 5, which tells the care team how abnormal the cells appear (making them more likely to spread quickly). Prostate-specific antigen levels, or PSA test levels, may also be any value in Stage 4.

To help doctors define more closely the level of spread, Stage 4 prostate cancer is divided into Stage 4A and Stage 4B.

Stage 4A: Cancer cells are in one or both sides of the prostate and the cancer is found in a nearby lymph node. It may also have spread to the seminal vesicles nearby (small glands that are part of the male reproductive system) or to other nearby structures, such as the rectum, bladder or pelvic wall. The TNM staging for 4A is any T, N1 and M0.

Stage 4B: Cancer has spread to distant parts of the body, such as the bones, other organs or distant lymph nodes. It may or may not be found in structures or lymph nodes near the prostate. The TNM staging for 4B is any T, any N and M1.

Where Do Prostate Cancer Metastases Occur?

In some cases, cancer cells may break away from the main tumor in the prostate and travel to other areas through the blood or lymph system. This is known as metastasis.

Prostate cancer metastases may appear anywhere in the body, but certain locations are more likely. Common locations for prostate cancer metastases to appear include the lymph nodes, rectum, bladder, pelvic wall and bones.

Some patients may experience a condition known as oligometastatic prostate cancer (omPCa), which affects the bones. With this type of stage 4 prostate cancer, very few metastatic tumors (usually less than five) are present.

If a patient receives a metastatic prostate cancer diagnosis, the care team will explain where the cancer has spread and will create a treatment plan with the location, stage, grade and other factors in mind.

Stage 4 Prostate Cancer Symptoms

Patients with Stage 4 prostate cancer may experience:

• The need to urinate frequently, especially at night
• Difficulty starting to urinate
• Weak stream or stream that starts and stops
• Sensation that the bladder does not feel completely empty after urinating
• Pain (most commonly in the back, hips or pelvis)
• Shortness of breath
• Extreme tiredness
• Rapid heartbeat
• Dizziness
• Anemia (low blood iron levels)

These signs and symptoms may also be caused by other medical conditions besides prostate cancer. This is why it is important to see a doctor to receive an accurate diagnosis and prostate cancer treatment plan.

Stage 4 Prostate Cancer Treatment

Several state-of-the-art treatment options are available for metastatic prostate cancer. These may be provided as standalone treatments or in combination. The most common treatments for Stage 4 prostate cancer include those listed below.

Hormone therapy: Male sex hormones may cause prostate cancer cells to grow and spread. Hormone therapy for prostate cancer blocks or reduces levels of these hormones, slowing the growth of the cancer.

Bisphosphonate therapy: Bisphosphonate medications are used to slow the growth of prostate cancer that has spread to the bones. These drugs may also be used to prevent bone loss from using hormone-blocking therapies.

External radiation therapy: External radiation therapy for prostate cancer uses high-energy X-rays to precisely target and destroy cancer cells or prevent them from growing.

Alpha emitter radiation therapy: For this therapy, special radioactive substances injected into a vein travel through the body to areas of the bone with cancer, destroying cancer cells.

Transurethral resection of the prostate (TURP): While this surgery does not directly treat prostate cancer, it may be used to remove tissue from the prostate to help relieve some urinary symptoms of Stage 4 prostate cancer.

Stage 4 Prostate Cancer Survival Rate

Survival rates are statistical estimates of the percentage of patients who are expected to survive their cancer. These estimates are based on large groups of patients in the past who were still alive five years after receiving the same diagnosis. They do not predict exactly what will happen to an individual patient since no two patients are alike.

The National Cancer Institute estimates that the five-year relative survival rate for patients whose prostate cancer has spread to distant areas of the body (metastatic prostate cancer) is 34.1%.

It is important to remember that clinical trials of new treatments for prostate cancer are underway at many hospitals, including City of Hope cancer centers.

These trials are used to determine whether new cancer treatments are safe and effective. Patients should talk to their care team to discuss whether they qualify for prostate cancer research trials.