The prostate is a muscular, walnut-sized gland that surrounds part of the urethra, the tube that carries urine and sperm out of the body. (A gland is a group of cells that secretes chemicals that act on or control the activity of other cells or organs.)
The main function of the prostate is to produce fluid for the semen, the milky fluid in which sperm swims. Sperm is produced in the testicles, which also make the main male hormone testosterone. During puberty, testosterone stimulates the growth and function of the prostate, and helps with the production of fluid for semen.
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During sexual climax (orgasm), the muscles of the prostate tighten to push the semen through the urethra and out through the penis (ejaculation). The urethra also carries urine, a waste product made by the kidneys and stored in the bladder. When the penis is erect during sexual intercourse, the flow of urine is blocked from the urethra, ensuring that it is only semen that is ejaculated in an orgasm.
Where is the prostate located?
The prostate is located directly beneath the bladder and in front of the rectum. The urethra passes through the prostate, so if the prostate becomes enlarged, it can keep urine or semen from passing through the urethra.
What is prostate cancer?
Prostate cancer is the most common cancer in men, and the second leading cause of cancer death among men in the U.S. More than 180,000 men in the U.S. will be diagnosed with prostate cancer this year, and more than 40,000 will die of the disease. Eighty percent of men who reach age 80 have prostate cancer.
Prostate cancer is a malignant (cancerous) tumor that usually begins in the outer part of the prostate. In most men, the cancer grows very slowly. In fact, many men with the disease will never know they had the condition. Early prostate cancer is limited to the prostate gland itself, and most patients with this type of cancer can live for years with no problems.
Prostate cancer is classified by two categories: "grade" and "stage." The size and extent of the tumor determine its stage. Early stage prostate cancer, Stages T1 and T2, are limited to the prostate gland. Stage T3 prostate cancer has advanced to tissue immediately outside the gland. Stage T4 prostate cancer has spread to other parts of the body.
What causes prostate cancer?
Like many cancers, the cause of prostate cancer is unknown. But doctors do know that it is more common in African-American men and men with a family history of the disease. The male sex hormone testosterone also contributes to its growth.
What are the symptoms of prostate cancer?
Prostate cancer, by nature, is “silent” in its early stages. Its symptoms don't appear until later, when patients may notice a need to urinate frequently, particularly at night. Prostate cancer may also cause other problems with urination, including:
- Having trouble urinating;
- A flow of urine that is weak or stops and starts; or,
- Painful and burning urination.
Other symptoms may include:
- Painful ejaculation
- Blood in urine or semen, and,
- Frequent pain or stiffness in the lower back, hips, or legs.
Who is at risk for prostate cancer?
The number of cases of prostate cancer has dropped among white American men. Among black men, the disease rate and death rate are twice as high as those of white men, according to the American Cancer Society.
The following are some of the risk factors for prostate cancer:
- Age. The greatest risk factor for prostate cancer is age. More than 75 percent of all prostate cancers are diagnosed in men older than 65.
- Family history. Men whose relatives have had prostate cancer are considered to be at high risk. Having a father or brother with the disease doubles your risk for prostate cancer, according to the American Cancer Society. Therefore, screening for prostate cancer should be started at age 40 in men with a family history of the disease.
To date, two genes have been identified that can lead to prostate cancer. Experts estimate that the hereditary form of prostate cancer accounts for just 9 percent of all cases.
- Race. African-Americans have the highest incidence of prostate cancer. They are 30 to 50 percent more likely to develop prostate cancer than other races in the U.S. Japanese and African men living in their native countries have a low incidence of prostate cancer. Rates for these groups increase sharply when they immigrate to the U.S.
African-American men, therefore, are another group for whom prostate cancer screening should begin at age 40. The higher rate of prostate cancer in African-American men suggests that the environment may play a role, including: high-fat diets, not enough exposure to the sun, exposure to heavy metals such as cadmium, infectious agents, or smoking.
- Diet. Research also suggests that a high-fat diet may lead to prostate cancer. The disease is much more common in countries in which meat and dairy products are commonly eaten, compared with countries in which the basic diet consists of rice, soybean products, and vegetables.
- Male hormones. High levels of male hormones called androgens may increase the risk of prostate cancer for some men, according to the American Cancer Society.
- Inactive lifestyle. You may be able to reduce your risk for prostate cancer by getting regular exercise and maintaining your ideal weight.
How is prostate cancer detected?
The most effective means of detecting prostate cancer early is through a screening, which involves a digital rectal exam and measuring the amount of prostate-specific antigen (PSA) in the blood. In a digital rectal exam, the doctor inserts a gloved, lubricated finger into the anus in order to feel the shape and size of the prostate.
The PSA test is believed to find most prostate cancers. PSA is a protein that the prostate secretes into the bloodstream. If a man has higher levels of this antigen, it may mean he has prostate cancer.
If cancer is suspected, the doctor will perform a prostate biopsy (removal of tiny pieces of prostate tissue). By removing a tissue sample from the tumor and examining it, doctors can confirm or rule out a diagnosis of cancer and determine whether the disease has spread to other organs.
What if prostate cancer is diagnosed?
Fortunately, most prostate cancers have not spread at the time they are diagnosed, and the cancer is most often limited to the prostate gland.
To help predict how aggressive the prostate cancer is, your physician will look at your PSA levels before the biopsy, and will also calculate the “Gleason Score.” The Gleason Score is a sum of the grades of the two most common prostate tumors.
After looking at tiny sections of the prostate tissue biopsy through a microscope, the pathologist assigns a grade from 1 to 5 to the tumors, based on their appearance (with 1 being closest to normal appearance and 5 being least normal). The Gleason Score can range from 6 to 10, with 6 being the least aggressive form of cancer (confined to the gland) and 10 the most aggressive form (highest risk of spreading outside the gland).
From the PSA levels and the Gleason Score, a treatment plan is created. For men with a low risk of the cancer spreading outside the gland, staging studies such as bone scans and computed tomography scans are not needed. Men who have cancer with a higher likelihood of spreading may need these staging studies to learn where the cancer may have spread.
What are the treatment options for prostate cancer?
Physicians design prostate cancer treatment plans to meet their patient's needs, based on the type of cancer, the age of the person, how far the cancer has spread, and the general health of the patient.
- Observation or surveillance. For men with low-risk cancer, observation (watching) may be the first strategy.
- Laparoscopic radical prostatectomy. A minimally invasive procedure, a laparoscopic radical prostatectomy removes the prostate gland. Unlike conventional surgery, a laparoscopic prostatectomy requires only five small (button-hole) incisions (cuts into the skin). Through these incisions, a surgeon uses a laparoscope—a tiny camera—and surgical instruments to perform the operation and remove the prostate.
- Robotic radical prostatectomy. During this procedure, surgeons use a robot to guide the laparoscope through small incisions to remove the cancerous prostate and any other tissue that might be affected. Various robotic systems are available, which may consist of a 3-armed robot connected to a remote console. The surgeon operates the system while seated at the console. Foot pedals are used for control, and three-dimensional displays give the surgeon sharp, detailed views of the surgical field.
- Open radical prostatectomy. Open radical prostatectomy removes the entire prostate with an incision in the lower abdomen. Because the prostate wraps around the urethra, the surgeon must reconnect the bladder with the urethra after removing the prostate.
- Radiation therapy. Radiation therapy uses high-energy x-rays to kill cancer cells and shrink tumors. Radiation can be produced in two ways: external radiation, which comes from a machine outside the body; or internal radiation, in which materials that produce radiation (radioisotopes) are placed through thin plastic tubes into the area in which the cancer cells are found.
- Interstitial brachytherapy (seed implantation). Interstitial brachytherapy is a form of radiation therapy. A radiation oncologist and urologist place radioactive pellets or "seeds" into the prostate, and the pellets release radiation into the prostate and nearby tissue over time.
- Intensity-modulated radiotherapy. This is an advanced form of radiation therapy that can shorten the length of prostate cancer treatment by several weeks. High doses of radiation (guided by a computer) are delivered directly to the tumor, which reduces the risk to normal tissue.
- Cryotherapy. Small needle-shaped probes are inserted into the prostate to freeze it and kill the prostate cancer. This procedure, which is minimally invasive and does not require an incision, is performed either on an outpatient basis (the patient goes home the day of surgery) or with a one-night hospital admission. Patients recover in a matter of days and usually have very few after effects.
- Hormone therapy. Hormone therapy changes the body's hormone balance to prevent certain cancers from growing. Hormone therapy may be done using drugs that change the way hormones work, or with surgery that removes hormone-producing organs such as the testes.
- Chemotherapy. Chemotherapy uses drugs to kill cancer cells. Chemotherapy may be taken orally (by mouth) or injected into a vein. Chemotherapy is usually a systemic treatment, which means that the drugs enter the bloodstream, travel through the body, and can kill cancer cells anywhere in the body, including the prostate.
It’s important to note that PSA levels decrease after the prostate has been removed. If the prostate gland was totally removed to treat prostate cancer, a new rise in the PSA level may mean that the tumor has come back. Additional tests would then be needed to learn why the PSA level has increased.
Which prostate cancer treatment should I choose?
The type of treatment is mostly a matter of patient choice. You'll want to consider the pros and cons of each option for your own situation, and how aggressive and advanced your cancer is. As you begin your decision-making process, here are some issues to think about.
- Ask your doctor about the stage and grade of your cancer. This will give you information on how aggressive your cancer is. With this information, you and your doctor can discuss the risk that your cancer poses to your well-being and longevity, how well each treatment option might work in your situation, and what the treatment side effects might be.
- Consider your age and health. Younger patients in their 40s and 50s with decades of life ahead may choose to treat the cancer aggressively. Cancer discovered in men in their 70s is likely to be slow-growing and may not have time to affect their life before they would die of other causes. Poor health adds to the complexity and makes treatment more risky.
- Think about your quality of life after treatment. Radiation can cause impotence and other urinary and rectal symptoms. Surgery can cause impotence and incontinence. So there are some difficult trade-offs to make in the face of uncertainty. Some men fear their sex lives may change, others are more fearful of dying or the anxiety of untreated cancer and prefer treatment despite the potential side effects.
- Make sure you are getting balanced and impartial information. If your doctor is a surgeon, you may want to talk with a radiation therapist, and vice versa. Make sure you feel comfortable discussing all of your options with all of your doctors and that they have taken the time to answer all of your questions. You should also do your own research and not just rely on your doctor's opinion. Consult with your doctors armed with your questions. It is important to ask about your doctor's personal expertise and experience in treating cancers like yours, as this can help determine a successful outcome.
- Ask yourself how well you tolerate uncertainty and repeated doctor's visits to deal with your cancer. If you are considering "active surveillance," can you deal with knowing that you have an untreated cancer inside your body? Will you follow through with office visits to your doctor for repeat testing? Would more aggressive treatment fit your personality and anxiety level?
What is the outlook for men who have prostate cancer?
Eighty-nine percent of men diagnosed with prostate cancer will live at least 5 years, while 63% will live 10 years or longer.
Because prostate cancer is a slow-growing disease, many affected men will die from other causes. Many patients who have a prostate screening every year detect their prostate cancer while it can be cured.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on 7/29/2015...#8634