Metastatic Prostate Cancer And Its Treatment Guidelines

What Is Metastatic Cancer?

Metastatic cancer is cancer that has spread from where it started (also called a primary site). Cancer cells get detached from where they are started, and travel to other parts of the body through blood or lymph; the process is called metastases. Metastatic cancer has the same name as primary cancer; for example, prostate cancer that spreads to bones is called metastatic prostate cancer of the bone but not bone cancer. Some doctors consider metastatic cancer as stage IV cancer.

What Is Advanced Cancer?

Cancers that cannot be cured are called advanced cancers. Cancer cells do not go away from the body even after treatment. These cancers can be cured but controlled, thus extending the patient's life. Treatments for advanced cancer can cause:

• Shrinkage in the size of the tumor.
• Relieving the symptoms.
• Extending the life of patients.

What Is Metastatic Prostate Cancer?

Metastatic prostate cancer, also called stage IV cancer, has spread outside of the prostate. This indicates that cancer has spread locally to the bladder, rectum, lymph nodes, or to more distant parts of the body.

What Is Staging of Metastatic Cancer?

Prostate cancer is divided into four stages. Stage IV prostate cancer is considered metastatic prostate cancer. Staging determines the spread and aggressiveness of cancer, and it helps to plan the treatment.

Can PSA (Prostate-Specific Antigen) Levels Help in the Diagnosis of Metastatic Prostate Cancer?

Prostate-specific antigen (PSA) is a protein made by cells in the prostate gland. Normal, as well as cancer cells both, produce PSA, which is found in semen and blood.

How to Measure PSA in Blood?

It is measured in nanograms per milliliter (ng/dL). As PSA increases chances of prostate cancer also increase. But there is no limit set to tell if a man does or does not have cancer. Doctors use 4 ng/mL as a reference point in deciding prostate cancer.

• PSA Under 4 ng/mL in Blood: Prostate cancer develops when PSA levels are above 4 ng/mL. However, a level below 4 ng/mL does not guarantee that a person does not have cancer, in such conditions, a prostate biopsy is done.
• PSA Between 4 to 10 ng/mL: It is called borderline range, and there are chances of having prostate cancer.
• PSA More Than 10 ng/mL: Chances of having prostate cancer are high.

What Are the Common Sites of Spreading?

The common sites of spreading are:

• Bones.
• Lung.
• Liver.
• Lymph nodes.

What Are the Less Common Sites for Spreading?

The less common sites for spreading are:

• Muscles.
• Spleen.
• Salivary glands.
• Adrenal glands.
• Eyes.
• Breast.
• Kidneys.
• Brain.

What Is the Treatment for Metastatic Prostate Cancer?

Treating metastatic prostate cancer is similar to treating stage IV prostate cancer. At this stage, cancer is spread to other body parts, and it cannot be cured completely so treatment is mainly targeted to improve the quality and extend the life of the patient. Stage IV prostate cancers are divided into two types based on their spreading:

1. Stage IVA: Cancer cells in the prostate are spread to surrounding lymph nodes and tissues, but not to the distant organs of the body.
2. Stage IVB: Cancer cells in the prostate get detached and spread to other parts of the body like the lungs, liver, and bone.

Treating Stage IVA Prostate Cancers:

1. Radiation Therapy: It is of two types:

• External Beam Radiation Therapy: From a large machine high-powered X-rays or protons are targeted towards the prostate gland and its surrounding tissues like lymph nodes. This machine moves around the target area delivering high-energy X-rays in all directions. This causes cancer size to shrink and prevents the spreading to some extent, this can be combined with chemotherapy or surgery for better results.
• Internal Beam Radiation Therapy: Also called brachytherapy. In this small seeds of radioactive material are inserted directly into the prostate gland or the surrounding tissues. This radioactive material has a radiation effect and directly treats prostate cancer and prevents its spreading. Brachytherapy has more advantages than external beam radiation therapy because higher doses of radiation can be used to treat with minimal side effects on surrounding tissues, this can save the surrounding tissues from unnecessary damage, and also shorter treatment time.

2. Surgery: It is not the treatment option in case of metastases. But it can be done to relieve painful symptoms like difficulty in passing urine and to have a good quality of life. It is of two types:

• Lymph Node Surgery: If the cancer cells are spread to nearby lymph nodes in the pelvic area then surgical removal is indicated, to prevent the further spread.
• Prostate Surgery: Also called prostatectomy, where the prostate gland is completely removed. After surgery, patients should be monitored for PSA levels. Surgery can also be combined with hormone therapy or radiotherapy for a better prognosis.

3. Hormone Therapy: This is considered a mainline treatment for metastatic prostate cancer, but it stops working after a period of time.

• Testosterone Therapy: Cancer cells in the prostate gland require testosterone (androgen) for their growth, stopping the supply of testosterone can retard the growth of cancer cells and make them shrink in size. Luteinizing hormone-releasing hormone (LHRH) antagonists and agonists stop the testicle from producing testosterone.
• Orchiectomy: Surgical removal of testicles will lower the testosterone in the body. Hormone therapy also lowers testosterone levels in the body by orchiectomy rapidly drops down testosterone.
• Blocking Testosterone: Certain medications block testosterone from reaching the cancer cells like Niltumide, and Flutamide.

Treating Stage IVB Prostate Cancer -

1. Radiation Therapy: In case of bone metastases.
2. Chemotherapy: To relieve signs, symptoms, and pain and to prolong life.
3. Medications for Bone Building: Bone metastases could lead to thinning of bones, medications such as calcium and vitamin D3 are advised.
4. Radioactive Drugs: Infusion of radioactive drugs directly into the vein can relieve symptoms like bone pain. These drugs target cancer cells in the body.
5. Immunotherapy: Sipuleucel drugs train the immune system of the body to recognize the cancer cells and fight against them.
6. Supportive Care: Also known as palliative care mainly focuses on the symptoms and illness of the patients. It is nothing but extra care given to support the ongoing treatment and extend life.

Complementary Treatment:

• Massage.
• Acupuncture.
• Relaxation techniques.
• Yoga can relieve the pain and increase life expectancy.

Conclusion

Treating metastatic cancer is a multidisciplinary approach, with a goal intended to treat the symptoms, relieve pain, and improve the quality of life.