By National Cancer Institute
Prostate cancer is the second most common type of cancer among men in this country. Only skin cancer is more common. Out of every three men who are diagnosed with cancer each year, one is diagnosed with prostate cancer.
Cancer that forms in tissues of the prostate (a gland in the male reproductive system found below the bladder and in front of the rectum). Prostate cancer usually occurs in older men.
The prostate is part of a man's reproductive system. It is located in front of the rectum and under the bladder. It surrounds the urethra, the tube through which urine flows. A healthy prostate is about the size of a walnut.
The prostate makes part of seminal fluid. During ejaculation, seminal fluid helps carry sperm out of the man's body as part of semen.
Male hormones (androgens) make the prostate grow. The testicles are the main source of male hormones, including testosterone. The adrenal gland also makes testosterone, but in small amounts.
If the prostate grows too large, it squeezes the urethra. This may slow or stop the flow of urine from the bladder to the penis.
Cancer in the Prostate
When prostate cancer spreads, cancer is often found in nearby lymph nodes. If cancer has reached these nodes, it also may have spread to other lymph nodes, the bones, or other organs.
When cancer spreads from its original place to another part of the body, the new tumor has the same kind of abnormal cells and the same name as the primary tumor. For example, if prostate cancer spreads to bones, the cancer cells in the bones are actually prostate cancer cells. The disease is metastatic prostate cancer, not bone cancer. For that reason, it is treated as prostate cancer, not bone cancer. Doctors call the new tumor "distant" or metastatic disease.
No one knows the exact causes of prostate cancer. Doctors often cannot explain why one man develops prostate cancer and another does not. However, we do know that prostate cancer is not contagious. You cannot "catch" it from another person.
Research has shown that men with certain risk factors are more likely than others to develop prostate cancer. A risk factor is something that may increase the chance of developing a disease.
Studies have found the following risk factors for prostate cancer:
- Age: Age is the main risk factor for prostate cancer. This disease is rare in men younger than 45. The chance of getting it goes up sharply as a man gets older. In the United States, most men with prostate cancer are older than 65.
- Family history: A man's risk is higher if his father or brother had prostate cancer.
- Race: Prostate cancer is more common in African American men than in white men, including Hispanic white men. It is less common in Asian and American Indian men.
- Certain prostate changes: Men with cells called high-grade prostatic intraepithelial neoplasia (PIN) may be at increased risk for prostate cancer. These prostate cells look abnormal under a microscope.
- Diet: Some studies suggest that men who eat a diet high in animal fat or meat may be at increased risk for prostate cancer. Men who eat a diet rich in fruits and vegetables may have a lower risk.
Many of these risk factors can be avoided. Others, such as family history, cannot be avoided. You can help protect yourself by staying away from known risk factors whenever possible.
Scientists have also studied whether BPH, obesity, smoking, a virus passed through sex, or lack of exercise might increase the risk for prostate cancer. At this time, these are not clear risk factors. Also, most studies have not found an increased risk of prostate cancer for men who have had a vasectomy. A vasectomy is surgery to cut or tie off the tubes that carry sperm out of the testicles.
Most men who have known risk factors do not get prostate cancer. On the other hand, men who do get the disease often have no known risk factors, except for growing older.
Your doctor can check you for prostate cancer before you have any symptoms. Screening can help doctors find and treat cancer early. But studies so far have not shown that screening tests reduce the number of deaths from prostate cancer. You may want to talk with your doctor about the possible benefits and harms of being screened. The decision to be screened, like many other medical decisions, is a personal one. You should decide after learning the pros and cons of screening.
Your doctor can explain more about these tests:
- Digital rectal exam: The doctor inserts a lubricated, gloved finger into the rectum and feels the prostate through the rectal wall. The prostate is checked for hard or lumpy areas.
- Blood test for prostate-specific antigen (PSA): A lab checks the level of PSA in a man's blood sample. A high PSA level is commonly caused by BPH or prostatitis (inflammation of the prostate). Prostate cancer may also cause a high PSA level.
The digital rectal exam and PSA test can detect a problem in the prostate. They cannot show whether the problem is cancer or a less serious condition. Your doctor will use the results of these tests to help decide whether to check further for signs of cancer.
A man with prostate cancer may not have any symptoms. For men who have symptoms of prostate cancer, common symptoms include:
- Urinary problems
- Not being able to urinate
- Having a hard time starting or stopping the urine flow
- Needing to urinate often, especially at night
- Weak flow of urine
- Urine flow that starts and stops
- Pain or burning during urination
- Difficulty having an erection
- Blood in the urine or semen
- Frequent pain in the lower back, hips, or upper thighs
Most often, these symptoms are not due to cancer. BPH, an infection, or another health problem may cause them. Any man with these symptoms should tell his doctor so that problems can be diagnosed and treated as early as possible. He may see his regular doctor or a urologist. A urologist is a doctor whose specialty is diseases of the urinary system.
Diagnosing Prostate Cancer
If you have a symptom or test result that suggests cancer, your doctor must find out whether it is due to cancer or to some other cause. Your doctor will ask about your personal and family medical history. You will have a physical exam. You may have lab tests. Your visit may include a digital rectal exam, a urine test to check for blood or infection, and a blood test to measure PSA level.
You also may have other exams:
- Transrectal ultrasound: The doctor inserts a probe into the man's rectum to check for abnormal areas. The probe sends out sound waves that people cannot hear (ultrasound). The waves bounce off the prostate. A computer uses the echoes to create a picture called a sonogram.
- Cystoscopy: The doctor uses a thin, lighted tube to look into the urethra and bladder.
- Transrectal biopsy: A biopsy is the removal of tissue to look for cancer cells. It is the only sure way to diagnose prostate cancer. The doctor inserts a needle through the rectum into the prostate. The doctor takes small tissue samples from many areas of the prostate. Ultrasound may be used to guide the needle. A pathologist checks for cancer cells in the tissue.
If cancer is present, the pathologist studies tissue samples from the prostate under a microscope to report the grade of the tumor. The grade tells how much the tumor tissue differs from normal prostate tissue. It suggests how fast the tumor is likely to grow. Tumors with higher grades tend to grow faster than those with lower grades. They are also more likely to spread.
One system of grading prostate cancer uses G1 through G4. Another way of grading is with the Gleason score. The pathologist gives each area of cancer a grade of 1 through 5. The pathologist adds the two most common grades together to make a Gleason score. Or the pathologist may add the most common grade and the highest (most abnormal) grade to get the score. Gleason scores can range from 2 to 10.
Many men with prostate cancer want to take an active part in making decisions about their care. It is natural to want to learn all you can about prostate cancer and your treatment choices. However, shock and stress after the diagnosis can make it hard to think of everything you want to ask your doctor. It often helps to make a list of questions before an appointment.
To help remember what the doctor says, you may take notes or ask whether you may use a tape recorder. You may also want to have a family member or friend with you when you talk to the doctor - to take part in the discussion, to take notes, or just to listen.
You do not need to ask all your questions at once. You will have other chances to ask your doctor or nurse to explain things that are not clear and to ask for more details.
Your doctor may refer you to a specialist, or you may ask for a referral. Specialists who treat prostate cancer include urologists, urologic oncologists, medical oncologists, and radiation oncologists.
Getting a Second Opinion
Before starting treatment, you might want a second opinion about your diagnosis and treatment plan. Many insurance companies cover a second opinion if you or your doctor requests it. It may take some time and effort to gather medical records and arrange to see another doctor. Usually it is not a problem to take several weeks to get a second opinion. In most cases, the delay in starting treatment will not make treatment less effective. To make sure, you should discuss this delay with your doctor. Some men with prostate cancer need treatment right away.
Men with prostate cancer have many treatment options. The treatment that is best for one man may not be best for another.
Treatment may involve surgery, radiation therapy, or hormone therapy. You may have a combination of treatments. If your doctor recommends watchful waiting, your health will be monitored closely. You will have treatment only if symptoms occur or get worse.
Cancer treatment is either local therapy or systemic therapy:
- Local therapy: Surgery and radiation therapy are local treatments. They remove or destroy cancer in the prostate. When prostate cancer has spread to other parts of the body, local therapy may be used to control the disease in those specific areas.
- Systemic therapy: Hormone therapy is systemic therapy. Hormones are given to control cancer that has spread.
The treatment that is right for you depends on the stage of the cancer, the grade of the tumor, your symptoms, and your general health. Your doctor will describe your treatment choices and the expected results.
Because cancer treatments often damage healthy cells and tissues, side effects are common. Side effects depend mainly on the type and extent of the treatment. Side effects may not be the same for each man, and they may change from one treatment session to the next. NCI's booklet Know Your Options: Understanding Treatment Choices for Prostate Cancer can tell you more about treatments and their side effects.
You should consider both the expected benefits and possible side effects of each treatment option. You may want to discuss with your doctor the possible effects on sexual activity. You can work with your doctor to create a treatment plan that reflects your medical needs and personal values.
Surgery is a common treatment for early stage prostate cancer. Your doctor may remove the whole prostate or only part of it. In some cases, your doctor can use a method known as nerve-sparing surgery. This type of surgery may save the nerves that control erection. But if you have a large tumor or a tumor that is very close to the nerves, you may not be able to have this surgery.
Each type of surgery has benefits and risks. Your doctor can further describe these types:
- Radical retropubic prostatectomy: The doctor removes the entire prostate and nearby lymph nodes through an incision (cut) in the abdomen.
- Radical perineal prostatectomy: The doctor removes the entire prostate through a cut between the scrotum and the anus. Nearby lymph nodes may be removed through a separate cut in the abdomen.
- Laparoscopic prostatectomy: The doctor removes the entire prostate and nearby lymph nodes through small incisions, rather than a single long cut in the abdomen. A thin, lighted tube (a laparoscope) is used to help remove the prostate.
- Transurethral resection of the prostate (TURP): The doctor removes part of the prostate with a long, thin device that is inserted through the urethra. The cancer is cut from the prostate. TURP may not remove all of the cancer. But it can remove tissue that blocks the flow of urine.
- Cryosurgery: This type of surgery for prostate cancer is under study at some medical centers.
- Pelvic lymphadenectomy: This is routinely done during prostatectomy. The doctor removes lymph nodes in the pelvis to see if cancer has spread to them. If there are cancer cells in the lymph nodes, the disease may have spread to other parts of the body. In this case, the doctor may suggest other types of treatment.
The time it takes to heal after surgery is different for each man and depends on the type of surgery he has had. You may be uncomfortable for the first few days. However, medicine can help control the pain. Before surgery, you should discuss the plan for pain relief with your doctor or nurse. After surgery, your doctor can adjust the plan if you need more pain relief.
After surgery, the urethra needs time to heal. You will have a catheter. A catheter is a tube put through the urethra into the bladder to drain urine. You will have the catheter for 5 days to 3 weeks. Your nurse or doctor will show you how to care for it.
Surgery may cause short-term problems, such as incontinence. After surgery, some men may lose control of the flow of urine (urinary incontinence). Most men regain bladder control after a few weeks.
Some men may become impotent. Nerve-sparing surgery is an attempt to avoid the problem of impotence. If a man can have nerve-sparing surgery and the operation is a success, impotence may not last. In some cases, men become permanently impotent. You can talk with your doctor about medicine and other ways to help manage the sexual effects of cancer treatment.
If your prostate is removed, you will no longer produce semen. You will have dry orgasms. If you wish to father children, you may consider sperm banking or a sperm retrieval procedure.
Radiation therapy (also called radiotherapy) uses high-energy rays to kill cancer cells. It affects cells only in the treated area.
For early stage prostate cancer, radiation treatment may be used instead of surgery. It also may be used after surgery to destroy any cancer cells that remain in the area. In later stages of prostate cancer, radiation treatment may be used to help relieve pain.
Doctors use two types of radiation therapy to treat prostate cancer. Some men receive both types:
- External radiation: The radiation comes from a large machine outside the body. Men go to a hospital or clinic for treatment. Treatments are usually 5 days a week for several weeks. Many men receive 3-dimensional conformal radiation therapy. This type of treatment more closely targets the cancer. It spares healthy tissue.
- Internal radiation (implant radiation therapy or brachytherapy): The radiation comes from radioactive material usually contained in small seeds. The seeds are put into the tissue. They give off radiation for months. The seeds are harmless and do not need to be removed.
Side effects depend mainly on the dose and type of radiation. You are likely to be very tired during radiation therapy, especially in the later weeks of treatment. Resting is important, but doctors usually advise patients to try to stay as active as they can.
If you have external radiation, you may have diarrhea or frequent and uncomfortable urination. Some men have lasting bowel or urinary problems. Your skin in the treated area may become red, dry, and tender. You may lose hair in the treated area. The hair may not grow back.
Internal radiation treatment may cause incontinence. This side effect usually goes away. Lasting side effects from internal radiation are not common.
Both internal and external radiation can cause impotence. Internal radiation is less likely to have this effect.
Hormone therapy keeps prostate cancer cells from getting the male hormones (androgens) they need to grow. The testicles are the body's main source of the male hormone testosterone. The adrenal gland makes a small amount of testosterone.
Hormone treatment uses drugs or surgery. Drugs: Your doctor may suggest a drug that can block natural hormones.
- Luteinizing hormone-releasing hormone (LH-RH) agonists: These drugs can prevent the testicles from making testosterone. Examples are leuprolide and goserelin.
- Antiandrogens: These drugs can block the action of male hormones. Examples are flutamide, bicalutamide, and nilutamide.
- Other drugs: Some drugs can prevent the adrenal gland from making testosterone. Examples are ketoconazole and aminoglutethimide.
Surgery to remove the testicles is called orchiectomy. After orchiectomy or treatment with an LH-RH agonist, your body no longer gets testosterone from the testicles. However, the adrenal gland still produces a small amount of male hormones. You may receive an antiandrogen to block the action of the male hormones that remain. This combination of treatments is known as total androgen blockade. Studies have not shown whether total androgen blockade is more effective than surgery or an LH-RH agonist alone.
Doctors can usually control prostate cancer that has spread to other parts of the body with hormone therapy. The cancer often does not grow for several years. But in time, most prostate cancers can grow with very little or no male hormones. Hormone therapy is no longer helpful. At that time, your doctor may suggest other forms of treatment that are under study.
Hormone therapy is likely to affect your quality of life. It often causes side effects such as impotence, hot flashes, loss of sexual desire, and weaker bones. An LH-RH agonist may make your symptoms worse for a short time when you first take it. This temporary problem is called "flare." The treatment gradually causes your testosterone level to fall. Without testosterone, tumor growth slows. Your condition may improve. (To prevent flare, your doctor may give you an antiandrogen for a while along with the LH-RH agonist.)
Antiandrogens (such as nilutamide) can cause nausea, diarrhea, or breast growth or tenderness. Rarely, they may cause liver problems (pain in the abdomen, yellow eyes, or dark urine). Some men who use nilutamide may have difficulty breathing. Some may have trouble adjusting to sudden changes in light.
If used for a long time, ketoconazole may cause liver problems, and aminoglutethimide can cause skin rashes. If you receive total androgen blockade, you may have more side effects than if you have just one type of hormone treatment.
Any treatment that lowers hormone levels can weaken your bones. Your doctor can suggest medicines or dietary supplements that can reduce your risk of bone fractures.
The National Cancer Institute coordinates the National Cancer Program, which conducts and supports research, training, health information dissemination, and other programs with respect to the cause, diagnosis, prevention, and treatment of cancer, rehabilitation from cancer, and the continuing care of cancer patients and the families of cancer patients.