Prostate cancer
From MayoClinic.com Special to CNN.com

Introduction

 

Prostate cancer is cancer of the small walnut-shaped gland in men that produces seminal fluid, the fluid that nourishes and transports sperm.

For many men a diagnosis of prostate cancer can be frightening, not only because of the threat to their lives, but because of the threat to their sexuality. In fact, the possible consequences of treatment for prostate cancer — which include bladder control problems and erectile dysfunction (ED) or impotence — can be a great concern for some men.

If prostate cancer is detected early — when it's still confined to the prostate gland — you have a better chance of successful treatment with minimal or short-term side effects. Successful treatment of cancer that has spread beyond the prostate gland is more difficult. But treatments exist that can help control prostate cancer.

 

Signs and symptoms

 

Prostate cancer often doesn't produce any symptoms in its early stages. That's why many cases of prostate cancer aren't detected until it has spread beyond the prostate.

When signs and symptoms do occur, they may include the following:

 

Causes

 

Cancer is a group of abnormal cells that grow more rapidly than normal cells and that refuse to die. Cancer cells also have the ability to invade and destroy normal tissues, either by growing directly into surrounding structures or after traveling to another part of your body through your bloodstream or lymph system. Microscopic cancer cells develop into small clusters that continue to grow, becoming more densely packed and hard.

The prostate gland is the small, walnut-shaped gland that surrounds the bottom portion ("neck") of a male's bladder and about the first inch of the urinary tube (urethra), the channel that drains urine from the bladder. It's located behind the pubic bone and in front of the rectum. The prostate's primary function is to produce seminal fluid, the fluid that nourishes and transports sperm.

Prostate cancer usually grows slowly and initially remains confined to the prostate gland, where it may not cause serious harm. But if left untreated, prostate cancer can begin to invade tissues and cause damage, and it may spread to others areas of your body where it can cause significant harm. Some forms of prostate cancer are aggressive and can spread quickly to other parts of your body.

What causes prostate cancer and why some types behave differently are unknown. Research suggests that a combination of factors may play a role, including heredity, ethnicity, hormones, diet and the environment.

 

Risk factors

 

Knowing the risk factors for prostate cancer can help you determine if and when you want to begin prostate cancer screening. The main risk factors include:

 

When to seek medical advice

 

If you have difficulties with urination, see your doctor. This condition doesn't always relate to prostate cancer, but it can be a sign of prostate-related problems.

If you're a man older than 50, you may want to see your doctor to discuss beginning prostate cancer screening. Mayo Clinic doctors, in accordance with the American Cancer Society and the American Urological Association (AUA), recommend having an annual blood test to check for prostate-specific antigen (PSA) beginning at age 50, or earlier if you're at high risk for cancer. If you're black or have a family history of the disease, you may want to begin at a younger age. Mayo Clinic doctors, along with the AUA, also recommend that men have a yearly digital rectal exam beginning at age 40.

 

Screening and diagnosis

 

Prostate cancer frequently doesn't produce symptoms. The first indication of a problem may come during a routine screening test. Screening tests include:

Prostate biopsy
If initial test results suggest prostate cancer, your doctor may recommend a prostate biopsy. During a biopsy, small tissue samples are taken and analyzed to determine if cancer cells are present.

To do a biopsy, your doctor inserts an ultrasound probe into your rectum. Guided by images from the probe, your doctor identifies any suspicious areas. Then a fine, hollow needle is aimed at these areas of your prostate. A spring propels the needle into your prostate gland and retrieves a very thin section of tissue.

If an abnormal area is seen on the transrectal ultrasound, your doctor will likely biopsy that area. If no abnormality is seen, eight sections of tissue usually are taken from different areas of your prostate gland. Very large prostate glands may require more than eight biopsies to adequately assess the gland for cancer. A pathologist who specializes in diagnosing cancer and other tissue abnormalities evaluates the samples. From those, the pathologist can tell if the tissue removed is cancerous and estimate how aggressive your cancer is.

Determining how far the cancer has spread
Once a cancer diagnosis has been made, you may need further tests to help determine if or how far the cancer has spread. Many men don't require additional studies and can directly proceed with treatment based on the characteristics of their tumors and the results of their pre-biopsy PSA tests.

Grading
When a biopsy confirms the presence of cancer, the next step, called grading, is to determine how aggressive the cancer is. The tissue samples are studied, and the cancer cells are compared with healthy prostate cells. The more different the cancer cells are from the healthy cells, the more aggressive the cancer and the more likely it is to spread quickly.

Cancer cells may vary in shape and size. Some cells may be aggressive, while others aren't. The pathologist identifies the two most aggressive types of cancer cells when assigning a grade.

The most common cancer grading scale runs from 1 to 5, with 1 being the least aggressive form of cancer. Known as Gleason scores, these numbers may be helpful in determining which treatment option is best for you. The Gleason score adds the grades of the two most aggressive types of cancer cells; therefore, scoring may range from 2 (non-aggressive cancer) to 10 (very aggressive cancer).

Staging
After the level of aggressiveness of your prostate cancer is known, the next step, called staging, determines if or how far the cancer has spread. Your cancer is assigned one of four stages, based on how far it has spread:

 

Complications

 

Complications from prostate cancer are related to both the disease and its treatment. One of the biggest fears of many men who have prostate cancer is that treatment may leave them incontinent or impotent. Fortunately, therapies exist to help cope with or treat these conditions.

The typical complications of prostate cancer and its treatments include:

 

Treatment

 

There's more than one way to treat prostate cancer. For some men a combination of treatments — such as surgery followed by radiation or radiation paired with hormone therapy — works best. The treatment that is best for each man depends on several factors. These include how fast your cancer is growing, how much it has spread, your age and life expectancy, as well as the benefits and the potential side effects of the treatment.

The most common treatments for prostate cancer include the following:

Radiation
You can receive radiation therapy via external beams or radioactive implants:

Hormone therapy
When you have prostate cancer, male sex hormones (androgens) can stimulate the growth of cancer cells. The main type of androgen is testosterone. Hormone therapy either uses drugs to try to stop your body from producing male sex hormones, or involves surgery to remove your testicles, which produce most of your testosterone. This type of therapy can also block hormones from getting into cancer cells. Sometimes doctors use a combination of drugs to achieve both.

In most men with advanced prostate cancer, this form of treatment is effective in helping to slow the growth of tumors. Because it's effective at shrinking tumors, doctors use hormone therapy in some early-stage cancers — often in combination with radiation and sometimes with surgery. Hormones shrink large tumors so that surgery or radiation can remove or destroy them more easily. After these treatments, the drugs can inhibit the growth of stray cells left behind.

Some drugs used in hormone therapy decrease your body's production of testosterone. The hormones — known as luteinizing hormone-releasing hormone (LH-RH) agonists — can set up a chemical blockade. This blockade prevents the testicles from receiving messages to make testosterone. Drugs typically used in this type of hormone therapy include leuprolide (Lupron, Viadur) and goserelin (Zoladex). They're injected into a muscle or under your skin once every three or four months. You can receive them for a few months, a few years, or the rest of your life, depending on your situation.

Other drugs used in hormone therapy block your body's ability to use testosterone. A small amount of testosterone comes from the adrenal glands and won't be suppressed by leuprolide or goserelin. Certain medications — known as anti-androgens — can prevent testosterone from reaching your cancer cells. Drugs typically used for this type of therapy include flutamide (Eulexin), bicalutamide (Casodex) and nilutamide (Nilandron). They come in tablet form and, depending on the particular brand of drug, are taken orally one to three times a day. These drugs typically are given with an LH-RH agonist.

Simply depriving prostate cancer of testosterone usually doesn't kill all of the cancer cells. Within a few years, the cancer often learns to thrive without testosterone. Once this happens, hormone therapy is less likely to be effective. However, several treatment options still exist.

To avoid such resistance, intermittent hormone therapy programs have been developed. During this type of therapy, the hormonal drugs are stopped after your PSA drops to a low level and remains steady. You resume taking the drugs if your PSA level rises again.

Side effects of hormone therapy may include breast enlargement, reduced sex drive, impotence, hot flashes, weight gain and reduction in muscle and bone mass. Some of these drugs can also cause nausea, diarrhea, fatigue and liver damage.

Because most testosterone is produced in your testicles, surgical removal of your testicles (castration) also can be an effective form of therapy — especially for advanced prostate cancer. The procedure can be performed on an outpatient basis using a local anesthetic.

Radical prostatectomy
Surgical removal of your prostate gland, called radical prostatectomy, is another option to treat cancer that's confined to your prostate gland. During this procedure, your surgeon uses special techniques to completely remove your prostate and local lymph nodes, while trying to spare muscles and nerves that control urination and sexual function.

Two surgical approaches are available for a prostatectomy — retropubic surgery and perineal surgery:

During your operation, a catheter is inserted into your bladder through your penis to drain urine from the bladder during your recovery. The catheter will likely remain in place for one to two weeks after the operation while the urinary tract heals.

After the catheter is removed, you'll likely experience some bladder control problems (urinary incontinence) that may last for weeks or even months. Most men eventually regain control. Many men experience stress incontinence, meaning they're unable to hold urine flow when their bladders are under increased pressure, as happens when they sneeze, cough, laugh or lift. In some men, major urinary leakage persists, and secondary surgical procedures may be needed in an attempt to correct the problem.

Impotence is another common side effect of radical prostatectomy, because nerves on both sides of your prostate that control erections may be damaged or removed during surgery. Most men younger than age 50 who have nerve-sparing surgery are able to achieve normal erections afterward, and some men in their 70s are able to maintain normal sexual functioning. Men who had trouble achieving or maintaining an erection before surgery have a higher risk of being impotent after the surgery.

Chemotherapy
This type of treatment uses chemicals that destroy rapidly growing cells. Chemotherapy can be quite effective in treating prostate cancer, but it can't cure it. Because it has more side effects than hormone therapy does, chemotherapy often is reserved for men who have hormone-resistant prostate cancer, especially if their cancer is causing problems.

As new chemotherapy drugs are developed, trials continue using single-drug chemotherapy, multiple combinations of chemotherapy, and combinations of chemotherapy and hormone therapy. Early results are positive, but extensive experience with newer drug agents is pending. In the future, gene therapy or immune therapy may be more successful in treating metastasized tumors of the prostate. Current technology limits the use of these experimental treatments to a small number of centers.

Cryotherapy
This treatment is used to destroy cells by freezing tissue. Original attempts to treat prostate cancer with cryotherapy involved inserting a probe into the prostate through the skin between the rectum and the scrotum (perineum). Using a rectal microwave probe to monitor the procedure, the prostate was frozen in an attempt to destroy cancer cells. Poor precision in monitoring the extent of the freezing process often resulted in damage to tissue around the bladder and long-term complications such as injury to the rectum or the muscles that control urination.

More recently, smaller probes and more precise methods of monitoring the temperature in and around the prostate have been developed. These advances may decrease the complications associated with cryotherapy, making it a more effective treatment for prostate cancer. Although progress continues, more time is needed to determine how successful cryotherapy may be as a treatment for prostate cancer.

Watchful waiting
The PSA blood test can help detect prostate cancer at a very early stage. This allows many men to choose watchful waiting as a treatment option. In watchful waiting (also known as observation, expectant therapy or deferred therapy), regular follow-up blood tests, rectal exams and possibly biopsies may be performed to monitor progression of your cancer.

During watchful waiting no medical treatment is provided. Medications, radiation and surgery aren't used. Watchful waiting may be an option if your cancer isn't causing symptoms, is expected to grow very slowly, and is small and confined to one area of your prostate.

Watchful waiting may be particularly appropriate if you're elderly, in poor health or both. Many such men will live out their normal life spans without treatment and without the cancer spreading or causing other problems. But watchful waiting can also be a rational option for a younger man as long as you know the facts, are willing to be vigilant, and accept the risk of a tumor spreading during the observation period, rendering your cancer incurable.

 

Prevention

 

Prostate cancer can't be prevented, but you can take measures to reduce your risk or possibly slow the disease's progression. The most important steps you can take to maintain prostate health — and health in general — are to eat well, keep physically active and see your doctor regularly.

Eating well
High-fat diets have been linked to prostate cancer. Therefore, limiting your intake of high-fat foods and emphasizing fruits, vegetables and whole fibers may help you reduce your risk. Foods rich in lycopenes, an antioxidant, also may help lower your prostate cancer risk. These foods include raw or cooked tomatoes, tomato products, grapefruit and watermelon. Garlic and cruciferous vegetables such as arugula, bok choy, broccoli, brussels sprouts, cabbage and cauliflower also may help fight cancer.

Soy products contain isoflavones that seem to keep testosterone in check. Because prostate cancer feeds off testosterone, isoflavones may reduce the risk and progression of the disease.

Vitamin E has shown promise in reducing the risk of prostate cancer among smokers. More research is needed, however, to fully determine the extent of these benefits of vitamin E.

Getting regular exercise
Regular exercise can help prevent a heart attack and conditions such as high blood pressure and high cholesterol. When it comes to cancer, the data aren't as clear-cut, but studies do indicate that regular exercise may reduce your cancer risk, including prostate cancer.

Exercise has been shown to strengthen your immune system, improve circulation and speed digestion — all of which may play a role in cancer prevention. Exercise also helps to prevent obesity, another potential risk factor for some cancers.

Regular exercise may also minimize your symptoms and reduce your risk of prostate gland enlargement, or benign prostatic hyperplasia (BPH). Men who are physically active usually have less severe symptoms than men who get little exercise do.

Drug protection
Research on prostate cancer prevention has shown that the drug finasteride (Proscar, Propecia) can prevent or delay the onset of prostate cancer in men 55 years and older. This drug is currently used to control prostate gland enlargement and hair loss in men. However, finasteride also has been shown to contribute to increasing sexual side effects and to slightly raise the risk of developing higher grade prostate cancer. At the time, this drug isn't routinely recommended to prevent prostate cancer. However, if you're at higher risk for developing prostate cancer, discuss the use of finasteride with your doctor.

Finally, nonsteroidal anti-inflammatory drugs (NSAIDS) might prevent prostate cancer. These drugs include ibuprofen (Advil, Motrin, others) and naproxen (Aleve). NSAIDS inhibit an enzyme called COX-2, which is found in prostate cancer cells. More studies are needed to confirm whether NSAID use actually results in lower rates of prostate cancer or reduced deaths from the disease.

 

Coping skills

 

Once you receive a diagnosis of prostate cancer or treatment for this disease, you may experience a range of feelings — including disbelief, fear, anger, anxiety, emptiness and depression. You may not be able to get rid of these distressing feelings. But you can find positive ways to deal with them so they don't dominate your life. The following strategies can help you cope with some of the difficulties of prostate cancer:

 

Complementary and alternative medicine

 

As people take a more active role in their health care, many are exploring options of care that fall outside the realm of traditional medicine. In fact, a range of dietary supplements and herbal medicines offers new ways to prevent or treat prostate disease, and cancer in general. The question is, do these therapies work? Some do show promise and are slowly gaining acceptance in mainstream medicine. But the benefits and risks of many products and practices remain unproven. Unfortunately, the production of these products isn't well regulated, and the amount of active ingredient may vary from bottle to bottle or even pill to pill.

Herbal products marketed to relieve common prostate problems, such as frequent urination or a weak urine flow, include:

Taken in small to moderate amounts, these products appear to be safe. But they haven't been studied in large, long-term trials to confirm their safety or to prove they work.

Saw palmetto
An exception is the herb saw palmetto (Serenoa repens). Unlike other herbal supplements, it has been widely tested, and the results show promise. However, it is important to know that saw palmetto is recommended to treat the symptoms associated with benign prostate gland enlargement, not prostate cancer.

Saw palmetto is thought to work by preventing testosterone from breaking down into another form of the hormone associated with prostate tissue growth. In 1998, researchers with the Department of Veterans Affairs reviewed more than a dozen studies involving saw palmetto and concluded that the herb appears to be as effective as the medication finasteride (Proscar) in reducing the size of an enlarged prostate. It also appears to produce fewer side effects. The researchers recommended additional studies to determine the appropriate daily dosage of the supplement and its long-term effectiveness.

Saw palmetto works slowly. Most men begin to see an improvement in their urinary symptoms within one to three months. If after three months you haven't noticed any benefit from the product, it may not work for you. It appears safe to take saw palmetto indefinitely, but possible effects from long-term use are unknown.

One drawback of this herb, and many other such herbal products, is that it may suppress PSA levels in your blood. This action can interfere with the effectiveness of the PSA test. That's why if you take saw palmetto or other herbal medicines, it's important to tell your doctor before having a PSA test.

Lacking scientific evidence
A few herbal and dietary products claim to help cure or prevent cancer. There's no scientific evidence that these products work, and some may be dangerous. Three popular "cancer-fighting" supplements include:

Because it's not always easy to tell which products may be unsafe, interact negatively with other medications or affect your overall cancer treatment, it's best to talk with your doctor before taking any dietary or herbal product.

 

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