The Prostate

The prostate is a gland in a man's reproductive system. It makes and stores seminal fluid, a milky fluid that nourishes sperm. This fluid is released to form part of semen.

The prostate is about the size of a walnut. It is located below the bladder and in front of the rectum. It surrounds the upper part of the urethra, the tube that empties urine from the bladder. If the prostate grows too large, the flow of urine can be slowed or stopped.

To work properly, the prostate needs male hormones (androgens). Male hormones are responsible for male sex characteristics. The main male hormone is testosterone, which is made mainly by the testicles. Some male hormones are produced in small amounts by the adrenal glands.

Prostate Cancer: Who's at Risk

Researchers are studying factors that may increase the risk of this disease. Studies have found that the following risk factors are associated with prostate cancer

• Age: In the United States, prostate cancer is found mainly in men over age 55. The average age of patients at the time of diagnosis is 70.
  Family history of prostate cancer: A man's risk for developing prostate cancer is higher if his father or brother has had the disease.
• Race: This disease is much more common in African- American men than in Caucasian men. It is less common in Asian and American-Indian men.
• Diet and dietary factors: Some evidence suggests that a diet high in animal fat may increase the risk of prostate cancer. Likewise, a diet high in fruits and vegetables may decrease the risk. Studies are in progress to learn whether men can reduce their risk of prostate cancer by taking certain dietary supplements.

Although a few studies have suggested that having a vasectomy might increase a man's risk for prostate cancer, most studies do not support this finding. Scientists have studied whether benign prostatic hyperplasia (BPH), obesity, lack of exercise, smoking, radiation exposure, or a sexually transmitted virus might increase the risk for prostate cancer. At this time, there is little evidence that these factors contribute to an increased risk.

Detecting Prostate Cancer

A man who has any of the risk factors described above may want to ask a doctor whether to begin screening for prostate cancer (even though he does not have any symptoms), what tests to have, and how often to have them. The doctor may suggest either of the tests described below. These tests are used to detect prostate abnormalities, but they cannot show whether abnormalities are cancer or another, less serious condition. The doctor will take the results into account in deciding whether to check the patient further for signs of cancer. The doctor can explain more about each test

• Digital rectal exam - the doctor inserts a lubricated, gloved finger into the rectum and feels the prostate through the rectal wall to check for hard or lumpy areas.
• Blood test for prostate- specific antigen (PSA) - a lab measures the levels of PSA in a blood sample. The level of PSA may rise in men who have prostate cancer, BPH, or infection in the prostate.

Recognizing Symptoms

Early prostate cancer often does not cause symptoms. But prostate cancer can cause any of these problems:

• A need to urinate frequently, especially at night
• Difficulty starting urination, or holding back urine
• Inability to urinate
• Weak or interrupted flow of urine
• Painful or burning urination
• Difficulty in having an erection
• Painful ejaculation
• Blood in urine or semen
• Frequent pain or stiffness in the lower back, hips, or upper thighs

Any of these symptoms may be caused by cancer, or by other, less serious health problems. A man who has symptoms like these should see his doctor or a urologist (a doctor who specializes in treating diseases of the genitourinary system).

Diagnosing Prostate Cancer

If a man has symptoms or test results that suggest prostate cancer, his doctor asks about his personal and family medical history, performs a physical exam, and may order laboratory tests. The exams and tests may include a digital rectal exam, a urine test to check for blood or infection, and a blood test to measure PSA. In some cases, the doctor also may check the level of prostatic acid phosphatase (PAP) in the blood, especially if the results of the PSA indicate there might be a problem.

The doctor may order exams to learn more about the cause of the symptoms. These may include

• Transrectal ultrasonography - sound waves that cannot be heard by humans (ultrasound) are sent out by a probe inserted into the rectum. The waves bounce off the prostate, and a computer uses the echoes to create a picture called a sonogram.
• Intravenous pyelogram - a series of x-rays of the organs of the urinary tract.
  Cystoscopy - a procedure in which a doctor looks into the urethra and bladder through a thin, lighted tube.
• Biopsy - if test results suggest that cancer may be present, the patient will need to have a biospy. During a biopsy, the doctor removes tissue samples from the prostate, usually with a needle. A pathologist looks at the tissue under a microscope to check for cancer cells. If cancer is present, the pathologist usually reports the grade of the tumor. The grade tells how much the tumor tissue differs from normal prostate tissue and suggests how fast the tumor is likely to grow. One way of grading prostate cancer, called the Gleason System, uses scores of 2 to 10. Another system uses G1 through G4. Tumors with higher scores or grades are more likely to grow and spread than tumors with lower scores.
  If the physical exam and test results do not suggest cancer, the doctor may recommend medicine to reduce the symptoms caused by an enlarged prostate. Surgery is another way to relieve these symptoms. The surgery most often used in such cases is called transurethral resection of the prostate
• (TURP or TUR). In TURP, an instrument is inserted through the urethra to remove prostate tissue that is pressing against the upper part of the urethra and restricting the flow of urine. (Patients may want to ask whether other procedures might be appropriate.) Back to Top

Stages of Prostate Cancer

If cancer is found in the prostate, the doctor needs to know the stage, or extent, of the disease. Staging is a careful attempt to find out whether the cancer has spread and, if so, what parts of the body are affected. The doctor may use various blood and imaging tests to learn the stage of the disease. Treatment decisions depend on these findings.

Prostate cancer staging is a complex process. The doctor may describe the stage using a Roman number (I-IV) or a capital letter (A-D). These are the main features of each stage:

• Stage I / Stage A -- The cancer cannot be felt during a rectal exam. It may be found by accident when surgery is done for another reason, usually for BPH. There is no evidence that the cancer has spread outside the prostate.
• Stage II / Stage B -- The tumor involves more tissue within the prostate, it can be felt during a rectal exam, or it is found with a biopsy that is done because of a high PSA level. There is no evidence that the cancer has spread outside the prostate.
• Stage III / Stage C -- The cancer has spread outside the prostate to nearby tissues.
• Stage IV / Stage D -- The cancer has spread to lymph nodes or to other parts of the body.

Treatment for Prostate Cancer

Doctors who treat prostate cancer are urologists, radiation oncologists, and medical oncologists. Patients may find it helpful to talk to a specialist in each of these areas. Different types of specialists may have different thoughts about how best to manage prostate cancer.

The doctor develops a treatment plan to fit each patient’s needs. Treatment for prostate cancer depends on the stage of the disease and the grade of the tumor (which indicates how abnormal the cells look, and how likely they are to grow or spread). Other important factors in planning treatment are the patient’s age and general health, and his feelings about the treatments and their possible side effects.

Many men with prostate cancer want to learn all they can about their disease, their treatment choices, and the possible side effects of treatment so they can take an active role in decisions about their medical care. Prostate cancer can be managed in a number of ways: watchful waiting, surgery, radiation therapy, and hormonal therapy. Some patients receive a combination of therapies.

Watchful waiting may be suggested for some men who have prostate cancer that is found at an early stage and appears to be slow growing. Also, watchful waiting may be advised for older men or men with other serious medical problems. For these men, the risks and possible side effects of surgery, radiation therapy, or hormonal therapy may outweigh the possible benefits.

Surgery is a common treatment for early stage prostate cancer. The doctor may remove all of the prostate (a type of surgery called radical prostatectomy), or only part of it. In some cases, the doctor can use a new technique known as nerve-sparing surgery. This type of surgery may save the nerves that control erection. However, men with large tumors, or tumors that are very close to the nerves, may not be able to have this surgery.

In radical retropubic prostatectomy, the doctor removes the entire prostate and nearby lymph nodes through an incision in the abdomen.

In radical perineal prostatectomy, the doctor removes the entire prostate through an incision between the scrotum and the anus. Nearby lymph nodes are sometimes removed through a separate incision in the abdomen.

In transurethral resection of the prostate (TURP), the doctor removes part of the prostate with an instrument that is inserted through the urethra. The cancer is cut from the prostate by electricity passing through a small wire loop on the end of the instrument. This method is used mainly to remove tissue that blocks urine flow.

If the pathologist finds cancer cells in the lymph nodes, it is likely that the disease has spread to other parts of the body. Sometimes, the doctor removes the lymph nodes before doing a prostatectomy. If the prostate cancer has not spread to the lymph nodes, the doctor then removes the prostate. But if cancer has spread to the nodes, the doctor usually does not remove the prostate, but may suggest other treatment.

Radiation therapy (also called radiotherapy) uses high-energy x-rays to kill cancer cells. Like surgery, radiation therapy is local therapy; it can affect cancer cells only in the treated area. In early stage prostate cancer, radiation can be used instead of surgery, or it may be used after surgery to destroy any cancer cells that may remain in the area. In advanced stages, it may be given to relieve pain or other problems.

Radiation may be directed at the body by a machine (external radiation), or it may come from tiny radioactive seeds placed inside or near the tumor (internal or implant radiation, or brachytherapy). Men who receive radioactive seeds alone usually have small tumors. Some men with prostate cancer receive both kinds of radiation therapy.

For external radiation therapy, patients go to the hospital or clinic, usually 5 days a week for several weeks. Patients may stay in the hospital for a short time for implant radiation.

Hormonal therapy keeps cancer cells from getting the male hormones they need to grow. It is called systemic therapy because it can affect cancer cells throughout the body. Systemic therapy is used to treat cancer that has spread. Sometimes this type of therapy is used to try to prevent the cancer from coming back after surgery or radiation treatment.

There are several forms of hormonal therapy:

Orchiectomy is surgery to remove the one or both testicles, which are the main source of male hormones.

Drugs known as luetinizing hormone-releasing hormone (LH-RH) agonists can prevent the testicles from producing testosterone. Examples are leuprolide, goserelin, and buserelin.

Drugs known as antiandrogens can block the action of androgens. Two examples are flutamide and bicalutamide.

Drugs that can prevent the adrenal glands from making androgens include ketoconazole and aminoglutethimide.

After orchiectomy or treatment with an LH-RH agonist, the body no longer gets testosterone from the testicles. However, the adrenal glands still produce small amounts of male hormones. Sometimes, the patient is also given an anti-androgen, which blocks the effect of any remaining male hormones. This combination of treatments is known as total androgen blockade. Doctors do not know for sure whether total androgen blockade is more effective than orchiectomy or LH-RH agonist alone.

Prostate cancer that has spread to other parts of the body usually can be controlled with hormonal therapy for a period of time, often several years. Eventually, however, most prostate cancers are able to grow with very little or no male hormones. When this happens, hormonal therapy is no longer effective, and the doctor may suggest other forms of treatment that are under study.