Prostate Cancer Metastatic

Metastatic prostate cancer is cancer that begins in the prostate and spreads to other parts of the body, most often to the bones. While this advanced form cannot be cured, many treatments are available to control its growth, manage symptoms, and help patients live for years with a good quality of life.

What is metastatic prostate cancer?
Where does prostate cancer spread?
Symptoms
Diagnosis
Treatment options
Coping with metastatic prostate cancer

What is metastatic prostate cancer?

Metastatic prostate cancer is cancer that starts in the prostate and spreads to other parts of the body^[1]. It is also called advanced prostate cancer or stage 4 prostate cancer^[1]. The prostate is a small gland that sits just below the bladder and is part of the male reproductive system^[1].

Most prostate cancers are found when the cancer is only in the prostate. It is less common for someone to have metastatic prostate cancer when first diagnosed^[1]. Metastatic prostate cancer happens most often in people who had treatment for prostate cancer in the past, when the cancer comes back and spreads^[1].

Metastasis is the medical term for cancer that has spread to a part of the body outside of where it started^[3]. This happens when cancer cells break away from the main tumor and travel through the body via the bloodstream or lymphatic system, which is a network of vessels that carry fluid throughout the body^[3]. These cancer cells can collect and grow in different parts of the body, forming new tumors^[3].

In medical staging systems, metastatic prostate cancer is classified as M1, meaning the cancer has spread to distant parts of the body^[2].

Prostate
Bones
Lymph nodes
Liver
Lungs

Where does prostate cancer spread?

Prostate cancer can spread anywhere in the body, but it most commonly spreads to certain organs and tissues. The bones are the most frequent site where prostate cancer spreads^[2]^[3]. More than 50 years ago, over 20% of patients presented with bone spread at diagnosis, and bone remains the most common site of metastases today^[6].

After the bones, prostate cancer most commonly spreads to^[2]^[3]:

Lymph nodes in other parts of the body
Lungs
Liver
Brain (less common)

The cancer shows a strong preference for bone tissue, a phenomenon doctors call osteotropism^[6]. Several biological processes contribute to why prostate cancer cells favor the bones, including how blood flows through the body, specific signaling interactions between cancer cells and bone cells, and the favorable environment that bone provides for cancer growth^[6].

Not all patients with spreading cancer cells will develop visible metastases. The presence of scattered tumor cells in the bone does not always lead to the actual development of bone metastases^[6]. The ability of a cancer cell to reform a tumor is greatly influenced by its surrounding environment^[6].

Symptoms

Metastatic prostate cancer does not always cause symptoms, especially in the early stages^[1]. As the cancer grows and becomes more advanced, symptoms might develop.

Signs and symptoms of metastatic prostate cancer can include^[1]:

Feeling very tired
Having to urinate more often or feeling pain when urinating
Losing weight without trying
Nausea and vomiting
Pain, which might be felt in the back, hips, pelvic area or in a bone. The pain tends to get worse over time

You should make an appointment with a doctor or other healthcare professional if you have any symptoms that worry you^[1]. If you have been treated for prostate cancer in the past, it is important to tell your healthcare professional about this history^[1].

Diagnosis

Diagnosing metastatic prostate cancer often involves blood tests and imaging tests to look for signs that the cancer has spread to other parts of the body^[8].

PSA test

A prostate-specific antigen test, also called a PSA test, measures the amount of prostate-specific antigen in the blood^[8]. PSA is a substance that prostate cells make, and some of it circulates in the blood^[8]. Having a high level of PSA in your blood can be a sign of prostate cancer^[8].

Many people have regular PSA tests after prostate cancer treatment. A rising PSA level may be the first sign that the cancer has come back^[8]. If your PSA level has been going up, your healthcare team might recommend imaging tests to look for signs of metastatic prostate cancer^[8].

Imaging tests

Imaging tests make pictures of the body that might show the places where the cancer has spread^[8]. Your doctor will arrange scans and tests if you have symptoms that could be due to metastatic prostate cancer^[2].

Imaging tests used to detect metastatic prostate cancer include^[8]:

Bone scan: Uses small amounts of radioactive substances and a special camera to make pictures that may highlight areas of cancer within the bones
CT scan (computerized tomography scan): Uses X-ray techniques to create detailed images of the body
MRI scan (magnetic resonance imaging): Uses magnets and radio waves to create detailed pictures of soft tissues
PET scan (positron emission tomography): Uses radioactive tracers to detect cancer cells
PSMA PET scan: A newer and more sensitive imaging technology that can detect prostate cancer anywhere in the body^[5]

In the United States, imaging for metastatic disease is most commonly done with a CT scan or an MRI and a bone scan^[5]. PSMA PET imaging is a newer technology that has become available and offers improved detection^[5].

Treatment options

There are many treatments for metastatic prostate cancer^[1]. While treatments are not likely to cure the cancer, they can slow its growth, control symptoms, help you feel better, and help you live longer^[1]^[2].

Your treatment depends on several factors, including^[2]:

Your age and general health
How you feel about the treatments and side effects
Where your cancer is and where it has spread
Your PSA blood test level
The symptoms you might have
The treatment you have had before

Hormone therapy

Hormone therapy is one of the main treatments for metastatic prostate cancer^[16]. At diagnosis, prostate cancer usually depends on the hormone testosterone to grow^[5]^[14]. Doctors call this hormone-sensitive prostate cancer^[14].

Testosterone is the “fuel” that makes prostate cancer cells grow^[5]. Hormone therapy blocks or lowers the amount of testosterone in the body, cutting off the fuel supply for prostate cancer cells^[5]^[14].

For metastatic prostate cancer, you usually have hormone therapy as your first treatment^[16]. Most people have an injection to suppress testosterone production^[16]. You might have this hormone drug on its own, or together with another hormone drug^[16].

Current guidelines in the United States recommend giving a combination of two different drugs to block hormones in two different ways^[10]. In clinical trials, this approach has helped people live longer^[10]. For people at the highest risk of their cancer getting worse, guidelines recommend adding chemotherapy as well, creating what is called “triplet therapy”^[10]^[16].

Hormone therapy often controls metastatic prostate cancer for many months to years^[16]. But sometimes the cancer starts to grow again despite treatment. When this happens, doctors call it castration-resistant prostate cancer or hormone-refractory prostate cancer, meaning that hormone therapy is no longer working^[16].

Chemotherapy

Chemotherapy uses anticancer drugs to destroy cancer cells^[14]. Chemotherapy may be offered for metastatic prostate cancer, often combined with hormone therapy^[14]^[16]. The chemotherapy drug used most often is docetaxel, usually given with other medications^[14].

Chemotherapy can reduce bone pain and lengthen survival^[4]. It may be used alone or in combination with other medications^[4].

Radiation therapy

Radiation therapy uses high-energy rays or particles to destroy cancer cells^[14]. It may be offered for metastatic prostate cancer and is often given together with hormone therapy^[14].

External radiation therapy may be used to^[14]:

Relieve urinary problems caused by the tumor
Relieve pain where the cancer has spread to the bones
Treat the prostate and other areas of cancer in the body

You are more likely to have radiotherapy if your cancer has only spread to a small number of places^[16].

Targeted drugs and newer therapies

Several newer treatment options have been developed for metastatic prostate cancer^[2]^[9]:

PARP inhibitors: Targeted drugs that can be used in some patients with specific genetic characteristics
Radioisotope therapy: Uses radioactive substances to target cancer cells, particularly in the bones. Radium-223 is an example of this treatment
Lutetium-177 PSMA therapy (Pluvicto): A newer type of radiation that specifically targets a molecule on the surface of prostate cancer cells^[15]
Immunotherapy: Uses the patient’s own immune system to fight cancer. Some immunotherapies have FDA approval for metastatic prostate cancer^[15]

Treatments for bone metastases

When prostate cancer spreads to the bones, specific treatments can help manage symptoms and complications^[14]:

Bisphosphonates (such as zoledronic acid): Medications that help strengthen bones
Denosumab: A type of antibody therapy that helps prevent bone problems
Corticosteroids (such as prednisone): Medications that reduce inflammation
Radiation therapy to painful bone areas
Pain medicines

Clinical trials

Clinical trials test new treatments for metastatic prostate cancer^[2]. Your doctor might ask if you would like to take part in a clinical trial^[16]. Doctors and researchers conduct trials to make existing treatments better and to develop new treatments^[16].

Watchful waiting

In some cases, particularly for older men whose cancer is not causing symptoms, your doctor might recommend monitoring your cancer closely rather than starting treatment right away^[14]. You would then start treatment if you develop symptoms^[16].

Coping with metastatic prostate cancer

Finding out that your cancer cannot be cured is distressing and can be a shock^[2]^[17]. It is common to feel uncertain and anxious, and it is normal not to be able to think about anything else^[2]^[17].

Many men with advanced prostate cancer live a normal life for a number of years^[16]. Treatment can help control the cancer for some time and help to relieve symptoms^[2].

Getting information and support

Lots of information and support are available to you, your family, and your friends^[2]^[17]. Some people find it helpful to find out more about their cancer and the treatments they might have. Many people find that knowing more about their situation can make it easier to cope^[2]^[17].

Talk to your doctor or specialist nurse to understand^[2]^[17]:

What your diagnosis means
What is likely to happen
What treatment is available
How treatment can help you
What the side effects of the treatment are

You and your family will be looked after by a team of healthcare professionals who can support you^[2]. You can also talk to your specialist nurse for support^[17].

Managing emotions

Your friends and relatives might be able to support you and talk to you about your cancer^[17]. However, some families find it difficult to discuss the situation because they worry about the emotions it could bring up^[17].

You can help your family and friends by letting them know you would like to discuss what is happening and how you feel^[17]. You might find it easier to talk to someone outside your own friends and family. Counselling might help you find ways of coping with your feelings and emotions^[17].

Staying as well as possible

It is important that you feel as well as you possibly can^[17]. Tell your doctor or specialist nurse about any symptoms you have so they can help to control them^[17].

Thinking about your priorities and planning what you want to do can help you to feel more in control^[17]. You can talk to your doctor about managing your treatment around your plans^[17].