How is Prostate Cancer Treated?
Prostate Cancer is treated in many ways. Each of the specific treatment methods is described below.
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Removal of the Prostate by Surgery
Radiation Therapy
Hormone Therapy
Surgical Removal of the Testicles
Estrogen Therapy
LHRH Therapy
Antiandrogen Therapy
Intermittent Therapy
Chemotherapy
Removal of the Prostate by Surgery
Surgery can be used to remove cancer from the prostate and from nearby areas to which the cancer has spread. It is most often used during the cancer's early stages (Stage T1 and T2), when prostate cancer is located only within the prostate. Surgery may help prevent further spread of the cancer. If the cancer is small and located exclusively within the prostate, the surgery most often cures the disease.
Advantages
Radical Prostatectomy is a one-time procedure that may cure prostate cancer in its early stages and may help extend life in the later stages. Surgery avoids the problems seen with radiation therapy. These problems are discussed in the next section.
Disadvantages
Prostatectomy is a major operation that requires hospitalization and can produce side effects, including impotence, incontinence (loss of urinary control), and narrowing of the urethra, which can make urination difficult. Impotence occurs in a high percentage of patients. In recent years, however, the percentage of men with impotence following surgery has decreased because of a new nerve-sparing surgical technique. Incontinence may occur after surgery, but improves within six months in most men, remaining a problem in only a small percentage of patients.
Radiation therapy uses high-energy rays to kill prostate cancer cells, shrink tumours, or prevent cancer cells from dividing and spreading. Because the rays cannot be directed perfectly, they may damage both cancer cells and healthy cells nearby. If the dose of radiation is small and spread out over time, however, the healthy cells are able to recover and survive, and cancer cells eventually die.
Radiation therapy is usually used when prostate cancer has not spread beyond the prostate (Stages T1-T2). It can help prevent the cancer from spreading further. Like surgery, radiation therapy works best when the cancer is located in a small area. In early stages of prostate cancer, radiation therapy may cure the disease. Radiation therapy may also be used alone or in combination with hormone therapy when cancer cells have spread beyond the prostate to the pelvic area (Stage T3-T4) and for pain relief in prostate cancer that is no longer responding to hormone therapy and has spread to the bones (Stage M+).
Advantages
Avoids major surgery. Radiation therapy may cure prostate cancer in its early stages and may help extend life in later stages. It rarely causes loss of urinary control, and it leads to impotence less frequently than does surgery. New injectable radioactive compounds, such as those containing radioactive strontium, can provide pain relief from cancer that has spread to the bone. These new compounds have fewer side effects than do the radioactive phosphorous compounds that have been available for many years.
Disadvantages
Radiation therapy can cause a variety of side effects. Most of these are minor and disappear after therapy stops. Those side effects include tiredness, skin reactions in the treated areas, frequent and painful urination, upset stomach, diarrhea, and rectal irritation or bleeding. When radiation therapy is provided by an external machine, it can cause later development of impotence in some patients. Internal radiation therapy causes impotence less often, but may be associated with a temporary decrease in white blood cell or platelet counts, making the patient more susceptible to infection or bruising and bleeding.
Hormone therapy is most commonly used to treat cancer that has spread (metastasized) outside the pelvic area (Stages N+ and M+). Two types of hormone therapy can be used: 1) surgical removal of the testicles, which produce male hormones, or 2) drugs that prevent the production or block the action of testosterone and other male hormones. Hormone therapy cannot cure prostate cancer. Instead, it may slow the cancer's growth and reduce the size of the tumour or tumours.
Hormone therapy in combination with radiation therapy or surgery is also used in advanced stages or cancer when the disease had spread locally beyond the prostate (Stage T3-T3). This therapy helps extend life and relieve symptoms. When the cancer has spread beyond the prostate, complete surgical removal of the prostate is not common. In patients with early-stage cancer (Stage T2), hormone therapy may be used in combination with radiation therapy. A course of hormone therapy can also be used prior to surgery to reduce the size of the prostate and make it easier to remove.
The primary strategy of hormone therapy is to decrease the production of testosterone by the testicles. Regardless of the method of hormone therapy, however, the decrease in testosterone can result in certain side effects. These commonly include hot flashes, loss of sexual desire, and impotence. The specific methods used to reduce testosterone production or block the actions of testosterone and other male hormones are described below:
Surgical Removal of the Testicles
An operation called orchiectomy removes the testicles, which produce 95% of the body's testosterone.
Advantages
Orchiectomy is an effective procedure that is relatively simple and performed only once. Often, the patient is given a local or general anesthetic and is allowed to go home the same day as surgery.
Disadvantages
Orchiectomy is a surgical procedure, and many patients prefer a nonsurgical option if it will work as well. Many men also find it difficult to accept this type of surgery. Depending on the kind of anesthesia used, there may be special risks in certain types of patients. Orchiectomy may in some cases require hospitalization, and it is not reversible.
Another method, although not used much anymore, is to administer a female hormone such as Estrogen. Female hormones reduce the production of testosterone by the testicles. The most commonly used Estrogen in prostate cancer is diethylstilbestrol, or DES.
Advantages
Estrogen therapy is simple and involves taking a pill. Unlike, orchiectomy, Estrogen therapy does not involve removal of the testicles, and its effects can be reversed.
Disadvantages
Estrogen therapy produces various side effects of its own. Estrogen can cause water retention, embarrassing breast growth and tenderness, and symptoms such as stomach upset, nausea, and vomiting. In addition, even low doses of Estrogen may significantly increase the risk of heart and blood vessel problems.
Another method of treatment consists of administering a drug called a luteinizing hormone-release hormone analogue (or an LHRH analogue); this leads to a drop in testosterone. Taking an LHRH analogue works just as well as removal of the testicles but does not involve surgery. Currently available LHRH analogues are Zoladex¨ (goserelin acetate), Suprefact¨ (buserelin acetate) and Lupron¨ (leuprolide acetate).
Advantages
Administering LHRH analogue therapy is simple; it involves an injection every 1,2,or 3 months. Treatment with LHRH analogues is as effective as orchiectomy, but it does not require surgical removal of the testicles. It also avoids the side effects of Estrogen therapy.
Disadvantages
In a small percentage of patients, LHRH analogue therapy may cause a brief rise in cancer symptoms, such as bone pain, before the testosterone level begins to fall. This pain may be eased by the use of a pain reliever (such as aspirin or acetaminophen) or an antiandrogen drug, which is discussed next.
This therapy involves the use of a drug that blocks the action of male hormones. Such a drug is called an antiandrogen. Antiandrogen drugs are used in combination with LHRH analogue therapy. This combination therapy is commonly known as maximal androgen blockade (MAB) or combined androgen blockade (CAB). The currently available antiandrogens are Casodex¨ (bicalutamide), Euflex¨ (flutamide), Anandron¨ (nilutamide) and the steroidal anti-androgen Androcur¨ (cyproterone acetate). In some patients, antiandrogens may be used alone, or in combination with other oral drugs.
Advantages
Ongoing clinical trials suggest that men treated with MAB therapy live longer than men treated with LHRH analogue therapy alone. The combination use of an LHRH analogue and an antiandrogen can also be of benefit before or after prostate surgery or radiation therapy. There is some controversy concerning MAB, and you may wish to discuss this with your doctor.
Disadvantages
Some antiandrogens may cause diarrhea, nausea, vomiting and liver injury. They may impair the way your eyes adjust to the dark, and may make you sick if you consume alcoholic beverages.
This involves alternating hormonal therapy with a drug free interval. While it improves the patient's quality of life, it may not be suitable for all patients.
Chemotherapy is the use of powerful toxic drugs to attack cancer cells. The drugs circulate throughout the body in the bloodstream and kill any rapidly growing cells, including healthy ones. To destroy cancer cells while minimizing the harm to healthy ones, drugs are carefully controlled in dosage and frequency.
Chemotherapy is generally reserved for patients with advanced stage cancer (Stage M+) that no longer responds to hormone therapy. Chemotherapy drugs do not work well in many men with prostate cancer.
There are many different chemotherapy drugs, each with its own strengths and weaknesses. Often the drugs are used in combination with in another.
Advantages
Chemotherapy drugs provide an additional means of relieving the symptoms of advanced prostate cancer.
Disadvantages
Because the drugs circulate widely throughout the body and affect healthy as well as cancerous cells, they produce many side effects. These include hair loss, nausea, vomiting, diarrhea, lowered blood counts, reduced ability of the blood to clot, and an increased risk of infection. Most of the side effects disappear when the drugs are stopped. (Hair grows back when chemotherapy is stopped.)