Prostate cancer tumors are characterized by abnormal cell growth. Although the tumor may have started out small, and been confined to one area, some aggressive cancer cells can leave the tumor and travel through the lymph nodes or the blood vessels, and go to other areas of the body; this is called metastasis. It is possible for a benign tumor to become malignant and metastasize into other areas, also. When these cancerous cells reach other organs, glands, bones, or tissues, they start to grow new tumors.
Men normally have a prostate-specific antigen (PSA) protein present in their blood at a level of 4ng/mL (four nanograms per milliliter). When this level increases past four nanograms, there is a possibility of prostate cancer. If this level passes ten nanograms, there is a high possibility that the prostate cancer has metastasized into other areas of the body. Fifteen percent of newly diagnosed prostate cancers are advanced stage or metastasized cancers. Metastatic prostate cancer can also affect men who had a less advanced stage and were treated and were considered cured. This is called relapse (or recurrence) and happens in 10% – 30% of cases depending on the stage the cancer was at when first discovered and many other factors. Doctors do not know for sure what causes cancer to reoccur.
Survival rates differ in early stage and advanced stage prostate cancer. Men who have early stage prostate cancer which is localized, have more than a 90% chance of survival beyond five years. However, men whose cancer has metastasized have a 30% chance of survival beyond five years.
Whereas early stages of prostate cancer can be treated by surgery and many types of therapy, later stage metastatic cancer is rarely treated with surgery. The primary treatment of metastatic prostate cancer is hormone therapy. Metastatic prostate cancer is not considered a curable condition, but treatment can prolong life, delay the progression of the cancer, relieve cancer related symptoms, and improve the patient’s quality of life.
Hormone therapy for metastatic prostate cancer is called androgen deprivation therapy (ADT). Male hormones, such as testosterone, promote or stimulate tumor growth, so by reducing the level of male hormones in a patient’s body, the growth rate of the tumor can be slowed or even stopped. Hormone levels in the patient’s body can be controlled three ways: orchiectomy, LHRH agonist drug therapy, and hormone treatments. Orchiectomy is the removal of the testicles to reduce the amount or testosterone produced. LHRH agonist drug therapy involves taking a medication to disrupt the androgen (male hormone) production in the body. Another hormone treatment is the introduction of the female hormone, estrogen, to the body to reduce the amount of male hormone present. Side effects of hormone therapy can include decreased libido, impotence, hot flashes, enlarged breast tissue, hair thinning, and a decrease in penis or testicle size.
Usually, after a medication has been taken for a while, it starts to lose its effectiveness, and the same is true with hormone therapy. For those who have metastatic prostate cancer which is no longer responding positively to hormone therapy, there are two other treatments: chemotherapy and radiotherapy. Chemotherapy is administering drugs to the patient which will kill or slow down the growth of cancer. These drugs can be injected or taken orally, but have many temporary unpleasant side effects, such as vomiting, hair loss, and fatigue. Radiotherapy is using a machine to irradiate the area of the tumor with x-rays. This may shrink or destroy some of the cancer cells, and it often decreases pain associated with cancer which has spread to the bone. Side effects of radiotherapy can include an increase in urinary urgency or frequency, bladder pain, irritated bowels, diarrhea, and impotence.