Prostate cancer

Prostate cancer is the growth of abnormal, unhealthy cells in the male prostate gland. It's common in older men and usually grows slowly.


Anatomy
The prostate is a male gland located at the base of the bladder. It's normally the size of a walnut, but the size increases with age and in response to infections or tumors. The prostate surrounds the urethra (the tube that carries urine from the bladder out through the penis) and has ducts that open into the urethra. The prostate and other smaller glands produce fluids that combine with sperm to make semen. Cancer most often develops in the back section of the gland, which is located next to the rectum. Nerves that control erections are located on both sides of the gland and can be damaged by some treatments.

Causes/associated factors
Prostate cancer is often a very slow-growing cancer. Most men who have been diagnosed with prostate cancer die from a cause other than the cancer. However, prostate cancer can spread to other parts of the body -- most often, the bones or pelvic lymph nodes (small, round structures found in the groin area that help fight infection). Prostate cancer is the second most common type of cancer in American men (skin cancer is the first). An estimated one in six men will be diagnosed with prostate cancer at some point. However, the prognosis is generally good -- only about one man in 30 dies from the disease.
The cause of prostate cancer is unknown. Some studies seem to indicate that eating a diet high in fat, especially animal fat, increases the risk of prostate cancer. Researchers are currently studying genetic and other possible causes, including environmental factors. A family history of prostate cancer in a brother or father doubles your risk of developing the disease. The more relatives you have who've been diagnosed with prostate cancer, the greater your risk. Your risk also increases as you age, especially after age 50. (About three out of four men are diagnosed with prostate cancer after age 65.) For unknown reasons, African-American men have twice the risk of developing prostate cancer as Caucasian men. They're also more likely to be diagnosed at a more advanced stage of cancer and have poorer survival rates. Recent studies have shown no increased risk for prostate cancer after a vasectomy.


Signs/symptoms
Prostate cancer is often diagnosed before symptoms appear. During the early stages of prostate cancer, most men don't notice any symptoms. If syptoms appear, they'll vary depending on the tumor's size, location and how far it has advanced. Symptoms may include:
difficulty starting or stopping urine flow
more frequent urination with increased urination at night
urgent need to urinate
decreased force or interrupted flow of the urinary stream
inability to urinate
pain or burning during urination
painful ejaculation
impotence (erectile dysfunction -- difficulty having or sustaining an erection)
blood in the urine or semen
pain in the lower back, pelvis or upper thighs
swelling in the lower legs

Diagnosis
Diagnosing prostate cancer involves many steps. Because treatment is based on how far the cancer has advanced, an accurate diagnosis is extremely important. Various tests are used to help the doctor make a diagnosis, including the following:
Digital rectal exam (DRE)
The prostate gland is located beside the rectum and can be felt through the rectal wall. It's possible to feel tumors larger than 1/2 inch in diameter. In this exam, the doctor uses a gloved, lubricated finger to check the prostate gland for lumps or other abnormalities.

Prostate-specific antigen (PSA) test
The PSA blood test measures prostate-specific antigen, a protein made only by the prostate gland. Small amounts of this protein can normally be found in a man's blood. PSA blood levels often rise when the prostate is enlarged or traumatized, or you have an infection or prostate cancer. Many factors can influence PSA levels. A few men with prostate cancer will have a normal PSA, and some men who don't have prostate cancer will have a high PSA, so the test cannot be used by itself to make a diagnosis. It can be used with a digital rectal exam of the prostate. The PSA test should precede the DRE, since rectal manipulation can elevate the PSA level in the blood. Using these two tests in this way can lead to significantly improved cancer detection rates.

In general, PSA levels of four and below are considered normal, but the PSA level considered normal varies by age and risk group. Your doctor may try to increase the accuracy of cancer detection by using reference ranges specific to your age and risk group. For example, reference ranges allow for the increased incidence of benign prostatic hyperplasia (enlargement of the prostate gland) in aging men. Alternate methods for analyzing PSA, such as percent-free PSA, PSA velocity and PSA density (PSAD), are also being used to increase accuracy. If you have an abnormal PSA result, one of these methods may be used to help determine if you need a biopsy (taking a tissue sample for further examination). The usefulness of these methods is still being evaluated. So far there's no evidence that early diagnosis and treatment will improve your chance of surviving prostate cancer, so not all doctors routinely use these tests.

Transrectal prostatic ultrasound (TRUS)
If screening indicates the possibility of prostate cancer, your doctor will probably do a TRUS. Using sounds waves from a special probe inserted into the rectum, this test creates an image of the prostate gland. TRUS can help your doctor identify any suspicious areas on the gland that may be candidates for biopsy. As with the PSA and DRE tests, the TRUS test is not perfect and cannot be used alone to make a definite diagnosis of cancer.

Core needle biopsy
A biopsy of the prostate tissue (with TRUS guidance) is needed to confirm the presence of cancer cells. The biopsy typically involves inserting a small needle into the rectum, which then goes through the rectal wall into the prostate. It can also be done by inserting the needle through the skin between the scrotum and the anus. Local anesthetic may be used. Several samples are usually taken for microscopic examination by a pathologist. The biopsy is used to make the actual diagnosis and grade the tumor.

Grading and staging the tumor
Once prostate cancer has been diagnosed, each tumor is given a grade and stage to help the doctor determine treatment options. The grade describes the structure and characteristics of the tumor itself, and the stage of the tumor describes how far the tumor has spread. Although different staging and grading systems may be used, the focus is to define the treatment choices.

The pathologist determines the grade after examining the cancer cells from the biopsy. The Gleason system is the most commonly used grading scale. With this system, a scale of one to 10 (10 is the most aggressive) is used to label the tumor's aggressiveness.

Staging is a complicated process, which first requires further tests to determine exactly how far the cancer has spread. The TNM system is the most commonly used staging system. It defines how big the tumor is (T), whether it has spread to lymph nodes near the prostate (N), and whether it has spread (metastasized) to other areas of the body (M). Once determined, the grade and staging information is combined to describe the overall stage of the tumor, expressed as stages I to IV. Basically, in stages I and II the cancer is confined to the prostate, in stage III it has spread to nearby tissues, and in stage IV it has spread to lymph nodes or other parts of the body.

The following tests may be used to help the doctor stage the tumor:

X-rays: X-rays of the lungs or liver may help the doctor determine if the prostate cancer has spread to these organs.

Magnetic resonance imaging (MRI) or computed tomography (CT scan): These tests create cross-sectional pictures of the body through the use of computers. These imaging studies can help the doctor determine if the prostate cancer has spread to nearby lymph nodes or pelvic structures.

Bone scan: A bone scan can help the doctor determine if the cancer has spread to the bone. You'll be given an injection of radioactive material, which will be attracted to areas of the bone that have cancer or other diseases. Any areas of diseased bone will then appear on the films from the bone scan.

Local lymph node biopsies: A biopsy can help the doctor determine if the prostate cancer has spread outside the gland into the lymphatic system. During the biopsy, the doctor will remove tissue samples from the lymph node (usually with a needle) for further examination under a microscope.

Treatment
Since prostate cancer often grows slowly, it's unclear whether early detection and treatment prolong life. Many low-grade tumors do not become life threatening, which has created controversy about how to treat localized prostate cancer. It's important to have a team of doctors working with you to determine the best treatment options in your case. To get a range of opinions and perspectives, you may want to consider input from a variety of doctors, such as your primary care physician, an oncologist (a doctor who specializes in cancer), a urologist or other surgeon, and a radiation oncologist. You can also obtain up-to-date treatment information from organizations such as the American Cancer Society and the National Cancer Institute.
Your treatment options will depend on the size of the cancer, how fast it is growing, and whether it has spread. Your general health will also be taken into consideration. All the treatments can have serious side effects, and the best treatment for the different stages has not yet been determined. Here are the common treatment options that are used alone or in combination:

Watchful waiting
This approach involves monitoring the activity of the prostate cancer through digital rectal exams and PSA testing every three to six months. There is no active treatment unless your condition changes. The purpose of watchful waiting is to monitor any growth or spread of the tumor. Currently, there is no test that can determine if a tumor will spread. Watchful waiting may be an option for extremely slow-growing prostate cancers, particularly for men who have a life expectancy of less than 10 years. Most men in an early stage of prostate cancer live at least 10 years with or without treatment.

Benefits of watchful waiting: With watchful waiting, you avoid the time, cost and potential complications of treatment. The life expectancy of those who choose watchful waiting appears to be similar to that of men treated with surgery, radiation or early hormonal therapy.

Risks of watchful waiting: Risks include possible spread of the cancer that may shorten your life span, particularly if you outlive your life expectancy. Treatment may become necessary when you're older and can't tolerate it as well. Some men become more anxious knowing they have untreated cancer.
Radical prostatectomy
This is the complete removal of the prostate gland. It's done either through an incision in your lower abdomen (retropubic surgery) or the skin between your anus and scrotum (perineal surgery). You'll be given general anesthesia, so you'll be asleep during the surgery, which usually lasts between two to four hours. You'll need a urinary catheter for one or two weeks following surgery to allow the urethra to heal. Radical prostatectomy is often done if your life span is expected to be more than 10 years and the tumor has not spread beyond your prostate gland. If your cancer has spread, surgery may be followed by hormone therapy.

Benefits of radical prostatectomy: This surgery has high long-term survival rates, but studies have not shown if these rates are better than those for other treatments or for no treatment at all. If you have retropubic surgery, you'll find out if the tumor has spread to nearby organs or lymph glands. (This isn't possible with perineal surgery.) For cancer that has spread, the combination of surgery and hormone therapy may slow the growth of the cancer better than surgery alone.

Risks of radical prostatectomy: Risks for this surgery include impotence, urinary incontinence (difficulty controlling the flow of urine with leaking of urine), infection, bleeding and rectal injuries that can make it difficult to control bowel movements. These problems result from injury to nearby tissues and nerves during surgery. If the tumor isn't large or located near nerves, doctor may be able to use a technique known as nerve-sparing surgery to decrease the risk of impotence. You will be infertile after surgery, because semen is no longer produced. If orgasms occur they will be dry (dry orgasm). Banking sperm before surgery may make it possible to father children in the future. There's a small risk of dying from surgery due to complications, such as breathing or heart problems.
Transuretheral resection of the prostate (TURP): During this procedure, part of the prostate is removed through an instrument that's inserted into the urethra. This is sometimes done if you're not a candidate for radical prostatectomy.

Benefits of TURP: This surgery may help relieve symptoms.

Risks of TURP: This surgery does not cure the cancer. Risks of surgery may include infection, bleeding, urinary incontinence and impotence.
Radiation therapy
Radiation is used to kill cancer cells. It can be effective for early cancer cases confined to the prostate. This may also be an option if you cannot have surgery due to your age or health, you have a tumor that will not be helped by surgery, or you simply choose not to have surgery. It can be used after surgery to destroy remaining cancer cells or in advanced illness to relieve symptoms. The radiation can be used externally or internally.

External radiation therapy uses a beam of radiation that's directed toward the prostate and sometimes the surrounding tissues from a machine located outside the body. It's usually given five days a week for six or seven weeks. External radiation may work for small, slow-growing tumors. However, it's not been studied well enough to know if it will actually help you live longer than if you had no treatment at all. For large tumors, hormonal medications may be given prior to the radiation to shrink the tumor, making it easier for the radiation to work.

External radiation benefits: Recent studies have indicated that external radiation treatment is almost as effective as surgery in preventing the cancer from spreading in the early stages of prostate cancer, and it may have fewer side effects than surgery.

External radiation risks: These may include urinary incontinence, cystitis (inflammation of the bladder, which may cause burning on urination, urgency, frequency or bleeding), proctitis (inflammation of the lining of the rectum, which may cause urgent and frequent stools, straining, rectal discomfort or bleeding), diarrhea, impotence or dry orgasm. These problems are caused by radiation damage to nearby normal tissues. Some of them may not start until several years after the treatment. 3-D conformal radiation, a newer technique that's available in some radiation centers, may decrease this risk by focusing the radiation beam more accurately on the cancerous tissue.
Internal radiation therapy (brachytherapy/interstitial therapy/seed implants) uses radioactive beads that are surgically inserted into the prostate through an incision made between the scrotum and rectum. The insertion is guided by transrectal ultrasound. A general or spinal anesthesia is necessary, but you will probably go home the same day. The beads remain there either temporarily or permanently. Internal radiation is best suited for men who have very small, slow-growing tumors. For other tumors, it may be used in combination with external radiation or hormone therapy. Initial treatments with this type of therapy was disappointing because the radiation was delivered unevenly, which led to a high failure rate. Recent changes in technology have improved the treatment, but studies have not yet shown if brachytherapy can stop the cancer from growing or spreading, or if it can prolong your life.

Internal radiation benefits: With radioactive implants, you avoid repeated trips to the hospital for radiation treatments or possible complications from major surgery and anesthesia. It's thought that internal radiation may have fewer side effects than external radiation, but this hasn't been studied adequately to be sure.

Internal radiation risks: These may include urinary incontinence, cystitis, proctitis, diarrhea and impotence. These problems are caused by radiation damage to nearby normal tissues. Some of them may not appear until several years after the treatment.
Hormone therapy
This treatment blocks the production or action of the male hormones (such as testosterone), which can stimulate tumor growth. It may cause the cancer cells to stop growing or die. It's generally used for men whose cancer has spread beyond the prostate gland. However, it's uncertain if it's best to start treatment as soon as the cancer is diagnosed, even if there are no symptoms, or wait until symptoms develop. Hormone therapy can also be used for men whose cancer appears not to have spread. For example, it can be done before radiation or surgery to shrink the tumor, after radiation or surgery if there are signs of continuing cancer, or with men who have chosen to monitor their cancer rather than treating it and have signs of cancer activity. Hormone therapy can be accomplished by surgery or medication.

Surgery: Surgically removing the testes (orchiectomy) permanently eliminates the main source of male hormones. It's a minor operation that's done through a small cut in the scrotum. You'll be given a general anesthetic so you'll be asleep during the surgery. Usually, you can go home the same day.

Medication: Two types of medications are also used for hormone therapy. They affect the male hormones only while you're taking them. These medications are:

Luteinizing hormone-releasing hormone (LHRH) agonists stop the production of male hormones. They're given by injection. Commonly prescribed medications include leuprolide (brand name Lupron, for example) and goserelin (Zoladex).

Antiandrogen medications stop testosterone from reaching the cancer cells, preventing their growth. They are given in pill form by mouth. Commonly prescribed medications include flutamide (Eulexin) and bicalutamide (Casodex).

Benefits of hormone therapy: The long-term benefits of hormone therapy are unknown. Research hasn't shown if it will prevent the cancer from spreading or improve your changes of surviving the disease. It can reduce the size of your tumor and ease symptoms, such as pain, difficulty with urination or bowel problems. If your cancer has already spread, starting treatment as soon as you're diagnosed, even if you have no symptoms, may improve your chance of living longer, but the evidence is inconclusive. It can also reduce your risk of developing severe cancer symptoms, such as broken bones, urinary incontinence and pain.
There's no evidence that one type of hormone therapy is better than another. Medications allow you to avoid the complications of more invasive treatment, and their effect can be reversed by stopping the medication.


Risks of hormone therapy: About 10 percent of prostate cancers will not respond to hormone therapy, but there's no way to tell this before the treatment. Most side effects of hormone therapy are due to a drop in testosterone. They include loss of sexual desire, impotence, hot flashes and breast enlargement. Your risk of developing osteoporosis (weakened bones) may also increase. If you receive an LHRH agonist injection, your cancer symptoms may actually worsen (tumor flare) for a couple of weeks, before they become better. If you use medication therapy, the earlier you start and the longer you're on it, the longer you'll experience side effects.
Cryotherapy
This therapy kills cancer cells by freezing the prostate tissue. Cryotherapy (also called cold therapy, cryoablation or cryosurgery) is being studied as an alternative to surgery and radiation therapy in early, localized prostate cancer. It can also be used when radiation hasn't been successful. The treatment is delivered with probes that are inserted into the prostate through an incision made between the scrotum and rectum. The insertion is guided by transrectal ultrasound (TRUS). The probes are then cooled to a temperature that will freeze the prostate gland. To protect your bladder and urethra from freezing, warm water is circulated through a tube inserted into the bladder through the urethra. The treatment takes about two hours, a general anesthesia is often used, and you will probably be in the hospital for one to two days. Because the prostate can swell and block the urethra after surgery, you'll need a urinary catheter for one to two weeks. Multiple treatments may be needed.

Benefits of cryotherapy: This treatment may be an option if you want to avoid other surgical procedures or radiation. It's less invasive than other surgical procedures, it's usually less painful, and the hospital stay is shorter.

Risks of cryotherapy: Surrounding prostate tissue may be damaged, possibly causing impotence or dry orgasm. Other problems that occur less frequently are urinary incontinence and the development of a fistula (a passageway that develops between the bladder and rectum, which allows urine to flow to the rectum). Cryotherapy is so new that the long-term risks and benefits are not yet known. It's uncertain whether it will destroy the cancer, prevent it from spreading or causing symptoms, or help you live longer.
New treatments
Ongoing clinical trials are studying newer forms of prostate cancer treatments. New combinations of chemotherapy have shown some promise. Prostate cancer vaccines, monoclonal antibody treatment and other medications are also being studied. Radiopharmaceuticals, another newer treatment approach, involves injecting radioactive substances that settle in bone areas that contain metastatic prostate cancer. The treatment is directed at relieving bone pain. Newer radiation treatment techniques, such as proton beam radiation and 3-D conformal radiation treatments, are also being used.


Complications
After treatment for localized prostate cancer, recurrence is possible. If prostate cancer spreads, it often affects the bones. This can result in problems such as bone pain, fractures or spinal cord compression with weakness or paralysis of the legs.

Senior-specific information
As stated above, the risk of developing prostate cancer increases with age.

Prevention
Studies have suggested that eating a diet low in animal fat (found in meat and dairy products) and high in fruits and vegetables (at least five servings a day) may help protect you from prostate cancer. Studies have also indicated that vitamin E, selenium, and a diet rich in tomatoes and soy may reduce your risk of prostate cancer. Research continues on these and other possible preventive measures, including the use of other dietary supplement, medications or genetic screening to identify men at high risk for prostate cancer.
To detect prostate cancer early, some health authorities recommend an annual digital rectal exam and prostate-specific antigen test for men age 50 and older. If you're at high risk for prostate cancer, your doctor may recommend starting these exams at age 40 to 45. (The U.S. Preventive Services Task Force does not recommend for or against routine screening, since there's no evidence that early diagnosis and treatment will improve your chance of surviving prostate cancer.)