Screening for Prostate Cancer

Screening for Prostate Cancer

What is the Prostate?

The prostate gland is a male sex gland located at the base of the urinary bladder directly in front of the lower rectum. In simplistic terms, you can think of the prostate as donut-shaped gland which lies just beneath a man's urinary bladder. Like a donut, it has a hole in the center. The tube that drains the bladder out through the penis is called the urethra. To do this, the urethra must pass through the hole in the center of the prostate. At birth, the prostate is about the size of a pea. With the hormonal changes of puberty, the prostate begins to grow. By the time a man reaches his twenties, the prostate has reached it's full adult size - about the size of a walnut.

What does the Prostate Do?

The primary purpose of the prostate gland is to produce the white fluid called semen which is mixed with sperm from the testicles; these two materials are discharged or ejaculated during sexual intercourse. The prostate also helps control the rate and flow of urination.

Disorders of the Prostate

Prostate Cancer

As men age, there are generally three major disturbances which may affect the prostate gland:

    1) Prostatitis is a inflammation of the prostate gland usually caused by bacterial infection. This is a common condition that affects millions of men at some point in their lives. It does not have anything to do with prostate cancer and is usually is seen in younger men. Symptoms may include urinary urgency, painful urination, scrotal discomfort, morning discharge, and blood in the urine or semen. Most episodes are self-limited and respond to a course of antibiotics, medications to relax the prostate, and, sometimes, prostatic massage. Sometimes, the condition reoccurs and becomes chronic and very frustrating to all concerned.

    2) Benign Prostatic Hyperplasia (BPH) is a non-cancerous enlargement of the prostate. As a man ages, the prostate usually becomes enlarged - both outward (which makes the prostate bigger) and inward (which may narrow the hole and squeeze the urethra). This non-cancerous enlargement is extremely common in older men. It usually starts at around age forty or so and keeps on going on until the day we die. Published estimates, and our experience over twenty to twenty-five years of urology practice, indicate that around 50% to 90% of men over fifty years of age experience such enlargement. Men with BPH complain of a frequent or sudden urgency, a weak, variable or dribbling urine stream, difficulty beginning urination, and the interrupted sleep to urinate at night. Treatment is directed at correcting the obstruction with medications or surgical procedures.

    3) Prostate cancer.

What is prostate cancer?

Cancer, in general, is not one disease, but a group of diseases which share two common traits - uncontrolled cell growth and migration of cancer cells to other organs. Normally, the billions of cells that make up the different tissues and organs of our bodies eventually wear out and are replaced by new young healthy cells. When cancer occurs, this process of new cell growth goes out of control and forms masses called tumors. Eventually, the cancer cells in the tumor can break away and spread to other parts of the body in a process is called metastasis.

Prostate cancer is a cancer that originates in the male prostate gland so only men are affected. Most prostatic cancers originate in the outer shell or peripheral zone of the gland. As they grow, they distort the normal tissue and produce a hard lump or "nodule." Prostate cancer usually grows very slowly. The American Cancer Society estimates that is takes 400 days for a tumor to double in size. But, if untreated, over time prostate cancer will invade the surrounding tissues and spread to the adjacent lymph nodes and then on to the bones, usually the spine and ribs. In advanced stages, prostate cancer may spread to the liver and lungs.

How common is prostate cancer?

It is common. A newborn male has a 13 percent chance of developing prostate cancer during his lifetime and a 3 percent chance of dying of it. These numbers are very similar to the numbers in breast cancer. There are over 185,000 new cases of prostate cancer in the United States each year and about 39,000 men die of this disease. Cancer of the prostate gland accounts for approximately 11% of all cancer deaths among men a rate that is second only to lung cancer. Furthermore, as the percentage of older Americans continues to grow, the death rate from this disease has simultaneously risen. It can be expected that as the "Baby Boomers" turn 50, this rise will continue in the future. Since most physicians consider cancers to be most curable when discovered at their smallest possible stages, it is logical that urologists have long sought methods to facilitate the earliest detection of prostatic cancer. [Click here] to see a list of personalities who have developed prostate cancer.

What are the risk factors?

Put in the simplest way, no one knows what causes some men to get prostate cancer while other men don't. Since the cause of prostate cancer is not known, there is no way accurately prevent or predict it. But, there are some important factors that may affect risk in general.

    Risk increases with age. Prostate cancer is rare under the age of 40 and most cases occur after the age of 60. A man's lifetime risk of developing prostate cancer is about 1 in 10.

    Family History
    Men who have a family history of prostate cancer (father, brother, uncle) may have a greater risk than the general population. However, this does not mean that just because your father had prostate cancer you will get prostate cancer! It does mean that the more relatives you have who had or have prostate cancer, the greater is your risk. Work is being done on finding a DNA marker which would help measure one's genetic risk.

    All races are affected, but the rate of prostate cancer varies around the world. Globally the United States and Scandinavia have the highest risk of prostate cancer and Asia the lowest. For example, U.S. rates for prostate cancer are 120 times higher than those of China. In this country, black males have twice the risk of whites.

    Some researchers feel that the high fat content of the typical American may stimulate prostate cancer cells to grow. Nutritionists urge all adults to eat less fat and add more fruits and vegetables to their diet. Recent studies have shown that men who ate more than 10 servings a week of tomato products (tomatoes, tomato sauce, tomato juice, or even pizza) had a reduced risk of prostate cancer. Some studies suggest that vitamin E supplements may reduce the risk although this has not yet been confirmed in long term scientific studies.

    Occupational exposure
    Workers exposed to the metal cadmium have a higher risk.

    Sexual history
    Men with many sexual partners or those with a history of a sexually transmitted disease may have a higher risk.

What are the symptoms of prostate cancer?

In the early stages, there are no symptoms. As the tumor enlarges and begins to restrict the flow of urine, obstructive symptoms occur which are quite similar to those of BPH. These symptoms are not diagnostic of prostate cancer, but should alert the man to call for an appointment.

  • frequent or sudden urge to urinate
  • weak, variable or dribbling urine stream
  • difficulty beginning urination
  • interrupted sleep to urinate at night (nocturia)
  • pain in the lower back
  • bone pain (when tumor spreads to bone)
The point is that symptoms are not helpful since they occur late in the disease and are also seen in other non-cancerous conditions such as prostatitis and BPH. So, a man can't use symptoms as a guide. To combat this common disease, you must see your doctor for regular checkups before symptoms occur.

Current Screening Recommendations

A recommendation then for the earlier detection of prostatic cancer is as follows:

An annual digital rectal examination plus a PSA for
  • All men over 50
  • All men over 40 with a close family history of prostate cancer
  • All African/American males over 40

A prostatic ultrasound study with possible biopsies for any men with abnormal rectal examinations or PSA's.

Appropriate treatment for the cancer if the biopsies prove to be positive for malignancy.

Repeated digital rectal examinations and PSA's every 6 months for those men undergoing ultra-sound studies and biopsies in whom the biopsies do not detect cancer; this 6 month program is continued until no further alteration in the rectal examination or PSA is noted.

Digital Rectal Exam

The ability of a physician to detect this lump or nodule when the prostate gland is examined by a lubricated gloved finger placed within the rectum (the "digital" rectal examination or DRE) represented for years the primary means for the detection of prostatic cancers. This is a simple test, but since only the back portion of the prostate is within reach of your doctor's finger, the results are not very definitive. Most men should undergo a yearly digital rectal examination once they have reached the age of 40 years; furthermore, other common "rectal" studies such as barium enemas and colonoscopies do not always directly examine the prostate gland and therefore should not be considered a substitute for this examination.

PSA Blood Test

However, not all cancers can be appreciated by rectal examinations-this is especially true for small tumors and hence other methods of detection have been sought. Over the years, a variety of blood tests have proven only somewhat helpful in detecting this disease. However recently, a new simple blood test, the PSA, has been developed which greatly expands your doctors' ability to help diagnose prostate cancer in its infancy. PSA is the abbreviation for prostatic specific antigen. This material is a protein produced by all types of prostatic tissue, especially cancerous or malignant tissue, which is then secreted into the blood stream. Thus, by testing your blood for abnormal levels of prostatic specific antigen (PSA), your doctor can far better determine the possibility that your prostate may or may not contain areas of cancer. It is generally recommended that men 50 years of age or older should have a PSA test yearly along with their digital rectal examination.

The PSA is measured in nanograms per milliliter of blood, or ng/ml. A PSA up to 4 ng/mls is considered normal. Between 4 and 10 is a gray area, and above 10 indicates an increased likelihood of cancer. Unfortunately, the PSA test is not totally reliable. A PSA of below 4 is not a guarantee that no cancer exists and an elevated PSA value does not mean that cancer is definite - but that further studies are needed for evaluation. PSA rises with prostatitis and enlargement (BPH). False positive readings may also occur due to sexual ejaculation within a day of having the examination or any activity that might cause stress to the rectal area, such as bicycling. In advanced prostate cancer, however, the PSA level may be several thousand units.

Last year, US Food and Drug Administration (FDA) approved a new test that detects "free" prostate specific antigen (PSA), or the amount of PSA in the blood that is not attached to proteins, and compares it to the total amount of PSA in the bloodstream. Early studies suggest that the use of the free/total PSA, or "PSA II test," in routine testing may help your doctor detect early prostate cancers and reduce the need for biopsy in some men. Time will tell if this new test is of value.

A combined approach

It is also very important to point out that neither the digital rectal examination nor the PSA determination represent "stand-alone" tests in the early detection of prostatic cancer. None of the tests has proven to be overly accurate or helpful when performed alone; they are most beneficial when utilized by your physician in a combined, coordinated, logical manner.

What if the screening tests are abnormal?

If the PSA test is elevated or if the digital exam detects a hard nodule or firm swelling of the prostate, your doctor may wish to do a transrectal prostate ultrasound (or ECHO) study and possibly perform a fine needle aspiration, or biopsy.

    Transrectal Prostate Ultrasound

    A small probe is placed in the rectum, directly behind the prostate gland, and sound waves are utilized to produce an actual picture of the prostate on a television monitor. Your urologist studies these pictures, searching for areas which appear suspicious for cancer. While prostate ultrasound has proven to be quite simple, accurate and safe, nevertheless, it is more involved than simple digital examinations or PSA determinations; therefore, this study is usually restricted to men whose prostate glands feel abnormal on rectal examination or those PSA levels are abnormal. Ultra sound can help the doctor determine the size of the prostate, to tell if cancer has spread from the prostate capsule to surrounding tissue, and to guide a needle biopsy.

    Fine Needle Aspiration (Biopsy)

    Any suspicious areas found on digital rectal exam or ultrasound can be immediately biopsied without the need for anesthesia using a very small needle guided through the probe. In this way, an abdominal incision and major surgery are not needed for the biopsy. During Fine Needle Aspiration (FNA) a needle about the size used to draw blood or administer an injection is guided by ultrasound into the prostate in the area where tumor is thought to be located. Tens of thousands of cells are extracted into a small syringe. The specimen is sent to the hospital laboratory where the cells can be examined for cancer. It is felt that needle biopsy is about 85% accurate in detecting cancer. If your doctor suspects cancer and the biopsy is normal, followup studies in 4 to 6 months are often suggested.

What if the biopsy shows cancer cells?

If the transrectal biopsy shows that cancer cells are present, then the diagnosis of prostate cancer is made. The next problem is to determine how advanced the cancer is by doing further tests to "stage" the disease. In this way, your doctor can learn more about the location of the cancer, how aggressively it has grown, and if it is still confined to the prostate, or has spread to the lymph nodes or bones. He can then best decide how aggressively to treat the cancer. Staging test may involve more blood tests, biopsies, x-rays, and even a small operation to remove and examine the adjacent lymph nodes. Different staging systems are available.

Once the test are completed, prostate cancer can be staged into one of four categories: A, B, C and D. This is called the Duke's Classification:

  • Stage A is very early and undetectable by the usual screening process.
  • Stage B is also confined to the prostate, but the tumor is palpable during the rectal exam and/or produces an abnormally high PSA reading. B1 is in one lobe of the prostate and smaller than 2 centimeters. B2 is in both lobes and larger than 2 centimeters.
  • Stage C cancer has left the prostate capsule but is still in its proximity.
  • Stage D cancer is in the regional lymph nodes or bones, liver, lungs and/or other tissue.
Another method that helps the doctor stage the disease is called the Gleason score. This is a number calculated by the doctor (pathologist) who reads the prostate biopsies. The Gleason Score is based on how "aggressive" the cancer cells look under the microscope. The lower the score the better. The range is from 2 to 10:

Gleason score of 2-4

well differentiated

least aggressive cancer

Gleason score of 5-7

moderately differentiated

average aggressive cancer

Gleason score of 8-10

poorly differentiated

most aggressive cancer

How is prostate cancer treated?

A lot depends upon the situation - especially the age of the patient, the stage of disease, and what other medical problems he may have. All treatments for prostate cancer have side effects - some are more serious than others. Sometimes the best treatment is no treatment at all, often called "conservative treatment" or "watchful waiting." Since prostate cancer grows very slowly, the best course of action in an older man with limited disease might be to simply monitor the situation. Almost all men over 80 have some cancer cells within their prostate, but most of them die of other natural causes - with prostate cancer, but not because of it."

In younger men or in those with more advanced disease, treatment is usually advised. Since younger men statistically have a longer life span, a cure is often sought and more aggressive treatment considered. In individuals with advanced disease that has spread beyond the prostate, a "cure" is not usually possible. Treatment is then directed at controlling symptoms and slowing the progress of disease.

If treatment is elected, there are many options to pick from - both surgical and non-surgical. The urologist often works in conjunction with other physicians such as cancer and radiation specialists to review a particular case and help the patient decide if and how their cancer should be treated.

Prostate Cancer Prevention Trial (PCPT)

Recently, the National Cancer Institute began the first large-scale prevention trial for prostate cancer. The Prostate Cancer Prevention Trial (PCPT) is designed to test whether taking the drug finasteride (Proscar) will prevent prostate cancer. This drug is currently used to treat BPH. Eighteen thousand men ages 55 and older are participating in the study at 222 sites across the country. Half are getting a placebo (sugar pill) and half are taking the drug finasteride daily. Neither the patients or the doctors know which pill each patient is receiveing. After seven years, both groups of patients will be examined with blood tests, rectal exams, and prostate biopsies. The hope is that finasteride will decrease the risk of prostate cancer more than the placebo.

Get a checkup

Prostate cancer is a common and potentially deadly disease of men over 50. There are no early warning symptoms or means of prevention. The best approach is to get a checkup when you feel well. The American Cancer Society and the American Urological Association recommend that a digital rectal examination and serum PSA determinations be performed on an annual basis in all men 50 years and older. If you are over 50, see your doctor at least once each year and be certain that prostate screening is part of your routine evaluation.

If you have symptoms that have not yet been evaluated, don't wait. Call your doctor for an appointment. Should a problem be found, don't panic. This is a slow growing process and there is plenty of time to consult your doctor to decide if treatment is needed and how aggressive treatment should be. Just do it.


Robert W. Doebler, M.D., F.A.C.S.

Valley Urological Associates
Sewickley Valley Hospital Office
Sewickley Valley Hospital - 4th Floor
701 Broad Street
Sewickley, PA 15143
412 741-8025

Text & Images Courtesy of Three Rivers Endoscopy Center
© Dr. Robert Fusco, Three Rivers Endoscopy Center, All Rights Reserved

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