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.
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 Factor :
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 :
- Age. As you get older, your risk of prostate cancer increases. After age 50, your chance of having prostate cancer increases substantially.
- Race or ethnicity. For reasons that aren't well understood, African-American men have a higher risk of developing and dying of prostate cancer.
- Family history. If a close family member — your father or brother — has prostate cancer, your risk of the disease is greater than that of the average American man.
- Diet. A high-fat diet and obesity may increase your risk of prostate cancer. Researchers theorize that fat increases production of the hormone testosterone, which may promote the development of prostate cancer cells.
- Surgery to become infertile (vasectomy). Although some studies suggest that men who've had a vasectomy are at increased risk for prostate cancer, no conclusive evidence to support such research has been found. Research on this issue is ongoing.
- High levels of testosterone. Because testosterone naturally stimulates the growth of the prostate gland, men who have high levels of testosterone, such as those with hypogonadism or men who use testosterone therapy, are more likely to develop prostate cancer than are men who have lower levels of testosterone. Long-term testosterone treatment could cause prostate gland enlargement (benign prostatic hyperplasia). Also, doctors are concerned that testosterone therapy might fuel the growth of prostate cancer that is already present.
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.
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 :
- Dull pain in your lower pelvic area
- Urgency of urination
- Difficulty starting urination
- Pain during urination
- Weak urine flow and dribbling
- Intermittent urine flow
- A sensation that your bladder doesn't empty
- Frequent urination at night
- Blood in your urine
- Painful ejaculation
- General pain in your lower back, hips or upper thighs
- Loss of appetite and weight
- Persistent bone pain
Prostate cancer frequently doesn't produce symptoms. The first indication of a problem may come during a routine screening test. Screening tests include :
- Digital rectal exam (DRE). During a DRE, your doctor inserts a gloved, lubricated finger into your rectum to examine your prostate, which is adjacent to the rectum. If your doctor finds any abnormalities in the texture, shape or size of your gland, you may need more tests.
- Prostate-specific antigen (PSA) test. A blood sample is drawn from a vein and analyzed for PSA, a substance that's naturally produced by your prostate gland to help liquefy semen. It's normal for a small amount of PSA to enter your bloodstream. However, if a higher than normal level is found, it may be an indication of prostate infection, inflammation, enlargement or cancer.
- Transrectal ultrasound. If other tests raise concerns, your doctor may use transrectal ultrasound to further evaluate your prostate. A small probe, about the size and shape of a cigar, is inserted into your rectum. The probe uses sound waves to get a picture of your prostate gland.
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.
- Bone scan. A bone scan takes a picture of your skeleton in order to determine whether cancer has spread to the bone. Prostate cancer can spread to any bones in your body, not just those closest to your prostate, such as your pelvis or lower spine.
- Ultrasound. Ultrasound not only can help indicate if cancer is present, but also may reveal whether the disease has spread to nearby tissues.
- Computerized tomography (CT) scan. A CT scan produces cross-sectional images of your body. CT scans can identify enlarged lymph nodes or abnormalities in other organs, but they can't determine whether these problems are due to cancer. Therefore, CT scans are most useful when combined with other tests.
- Magnetic resonance imaging (MRI). This type of imaging produces detailed, cross-sectional images of your body using magnets and radio waves. An MRI can help detect evidence of the possible spread of cancer to lymph nodes and bones.
- Lymph node biopsy. If enlarged lymph nodes are found by a CT scan or an MRI, a lymph node biopsy can determine whether cancer has spread to nearby lymph nodes. During the procedure, some of the nodes near your prostate are removed and examined under a microscope to determine if cancerous cells are present.
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).
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 :
- Stage I. Signifies very early cancer that's confined to a microscopic area that your doctor can't feel.
- Stage II. Your cancer can be felt, but it remains confined to your prostate gland.
- Stage III. Your cancer has spread beyond the prostate to the seminal vesicles or other nearby tissues.
- Stage IV. Your cancer has spread to lymph nodes, bones, lungs or other organs.
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 :
- Spread of cancer. Prostate cancer can spread to nearby organs and bones and can be life-threatening.
- Pain. Although early-stage prostate cancer typically isn't painful, once it's spread to bones, it may produce pain, which can be intense. Treatments directed at shrinking the cancer often can produce significant pain relief. These treatments include hormone therapy, radiation therapy and chemotherapy. If these treatments aren't successful, or while waiting for them to work, pain management with medications is an option. Pain medications can range from over-the-counter pain relievers to prescription narcotics.
Not all people with cancer that has spread to bones have pain. Pain can be controlled, and there's no reason a person has to suffer with intense pain. If your doctor is unable to control your pain effectively, you may need to consult a pain specialist. While it's not always possible to make all of your pain go away, your doctor will work with you to try to control pain to a point where you're comfortable.
Urinary incontinence. Both prostate cancer and its treatment can cause incontinence. Some men experience incontinence after surgery to remove the prostate. Treatment recommendations depend on the type of incontinence you have, how severe it is and the likelihood it will improve, given time. Treatments include behavior modifications (such as going to the bathroom at set times rather than just according to urges), exercises to strengthen pelvic muscles (commonly called Kegel exercises), medications and catheters.
If leakage problems have continued for a prolonged period without improvement, your doctor may suggest more aggressive procedures. These procedures may include implanting an artificial urinary sphincter, placement of a sling of synthetic material to compress the urethra, or the injection of bulking agents into the lining of the urethra at the base of the bladder to reduce leakage.
- Erectile dysfunction (ED) or impotence. Like incontinence, ED can be a result of prostate cancer or its treatment, including surgery, radiation or hormone treatments. Medications and vacuum devices that assist in achieving erection are available to treat ED. Medications include sildenafil (Viagra), tadalafil (Cialis) and vardenafil (Levitra). If other treatments fail, penile implants can be inserted surgically to help create an erection.
- Depression. Many men may develop feelings of depression after a diagnosis of prostate cancer or after trying to cope with the side effects of treatment. These feelings may last for only a short time, they may come and go, or they may linger for weeks or even months. Depression that lingers and interferes with your ability to manage your life should be treated. Treatment may involve counseling or antidepressant medication. A combination of the two therapies often is successful.
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:
You can receive radiation therapy via external beams or radioactive implants :
External-beam radiation therapy (EBRT). External beam radiation treatment makes use of high-powered X-rays to kill cancer cells, using a machine to deliver the radiation beam. This type of radiation is effective at destroying cancerous cells, but it can also scar adjacent healthy tissue.
The first step in radiation therapy is to map the precise area of your body that needs to receive radiation. Doctors often use three-dimensional scans to determine the exact location of your prostate and surrounding structures. Computer-imaging software gives the radiation oncologist the ability to find the best angles to aim the beams of radiation. By using new techniques — which allow for more precise focusing of the radiation beams with concentration of the radiation dose to the targeted area — greater doses of radiation can be administered to your prostate without harming surrounding tissue.
A body supporter holds you in the same position for each treatment. You'll also be asked to arrive for therapy with a full bladder . This will push most of your bladder out of the path of the radiation beam. Ink marks on your skin help to guide the radiation beam, and small gold markers may be placed in your prostate to ensure the radiation hits the same targets each time. Custom-designed shields help protect nearby normal tissue, such as your bladder, erectile tissues, anus, and rectal wall.
Treatments are generally given five days a week for about eight weeks. Each treatment appointment takes about 10 minutes. However, much of this is preparation time — radiation is received for only about 1 minute. You don't need anesthesia with external-beam radiation, because the treatment isn't painful.
Most men have mild side effects from this type of treatment, but most of the side effects disappear shortly after treatment is completed. Most men don't have problems with erections or intercourse immediately after radiation therapy. However, radiation can cause sexual side effects in some men later in life. Most of these men respond to medications used for ED. The younger you are, the better your chance of retaining normal sexual function.
During treatment some men experience urinary problems. The most common signs and symptoms are urgency to urinate and frequent urination. These problems usually are temporary and gradually diminish in a few weeks after completing treatment. Long-term problems are uncommon.
Rectal problems — including loose stools, rectal bleeding, discomfort during bowel movements and a sense that you have to have a bowel movement (rectal urgency) — may arise during treatment. Once the treatment course is complete, these problems generally subside. However, a few men may continue to experience rectal problems months after treatment, but these improve on their own in most men. Most long-term rectal symptoms are controlled with medications. Rarely, people develop persistent bleeding or a rectal ulcer after radiation. Surgery may be necessary to alleviate these problems.
Radioactive seed implants. Radioactive seeds implanted into the prostate have gained popularity in recent years as a treatment for prostate cancer. The implants, also known as brachytherapy, deliver a higher dose of radiation than do external beams, but over a substantially longer period of time.
During the implant procedure — which typically lasts about one to two hours, done under general anesthesia on an outpatient basis — between 40 and 100 rice-sized radioactive seeds are placed in your prostate through ultrasound-guided needles. The exact number of seeds inserted depends on the size of your prostate. The therapy is generally used in men with smaller or moderate-sized prostates with small and lower-grade cancers. Sometimes, hormone therapy is used for a few months to shrink the size of the prostate before seeds are implanted.
The seeds may contain one of several radioactive isotopes — including iodine and palladium. These seeds don't have to be removed after they stop emitting radiation.
Iodine and palladium seeds generally emit radiation that extends only a few millimeters beyond their location. This type of radiation isn't likely to escape your body in significant doses. However, doctors recommend that for the first few months you stay at least six feet away from children and pregnant women, who are especially sensitive to radiation. All radiation inside the pellets is generally exhausted within a year.
Side effects of seed implants are somewhat different from that of external-beam radiation. Seed implants deliver a higher dose of radiation to your urethra, causing urinary signs and symptoms such as frequent, slower and painful urination to occur in nearly all men. You may require medication to treat these signs and symptoms, and some men require medications or the use of intermittent self-catheterization to help them urinate.
Urinary symptoms tend to be more severe and longer lasting with seed implants than with external-beam radiation. Rectal symptoms, however, may be less frequent and less severe. Some men experience impotence due to radioactive seed implants.
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.
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 :
- Retropubic surgery. In this approach, the gland is taken out through an incision in your lower abdomen that typically runs from just below your navel to an inch above the base of your penis. It's the most commonly used form of prostate removal for two reasons. First, your surgeon can use the same incision to remove pelvic lymph nodes, which are tested to determine if the cancer has spread. Secondly, the procedure gives your surgeon good access to your prostate, making it easy to save the nerves that help control bladder function and erections.
- Perineal surgery. With the perineal approach, an incision is made between your anus and scrotum. There's generally less bleeding with perineal surgery, and recovery time may be shorter, especially if you're overweight. With this procedure, your surgeon isn't able to remove nearby lymph nodes.
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.
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.
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.
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.
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.
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.
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.