Screening refers to testing to find a disease such as cancer in people who do not have symptoms of that disease. Prostate cancer can often be found early by testing the amount of PSA (prostate-specific antigen) in your blood. Another way prostate cancer is found early is when the doctor does a digital rectal exam (DRE). This is when a doctor a puts a gloved finger into the rectum to feel the prostate gland. Because the prostate gland lies just in front of the rectum, during the DRE the doctor can feel if there are any bumps or hard places on the prostate. These might be cancer. If you have had routine yearly exams and either one of these test results becomes abnormal, any cancer you might have has probably been found at an early, more treatable stage.

Since about 1990 it has become more common for men to have tests to find prostate cancer early. The prostate cancer death rate has dropped, too. But we do not yet know if this drop is the direct result of the tests or caused by something else, like better treatments.

These tests are not perfect, though. Uncertain or false test results could cause confusion and worry. There is no question that the PSA test can help spot prostate cancer early. But it can't tell how dangerous the cancer is. The problem is that some prostate cancers are slow-growing and may never cause problems. But because of a high PSA level, many men will be found to have prostate cancer that would never have led to their deaths or even caused any problems. Often these men are being treated with either surgery or radiation, either because their doctor can't be sure how fast the cancer might spread or because the man is uncomfortable not having treatment. These treatments can lead to urinary or bowel problems or problems with sex. In some men these problems may be minor and go away quickly. But for others these problems can be severe and last a long time. Doctors and patients are still struggling to decide who should get treatment and who can be followed without treatment (called watchful waiting).

Studies are being done to try to figure out if early tests for prostate cancer in large groups of men will lower the prostate cancer death rate and help men live longer. The most recent results from 2 large studies didn't offer clear answers.

Until more is known, you should talk to your doctor about whether or not you want to be tested. Things to take into account are your age, your health, and the benefits and side effects of screening and treatment. If you are young and you get prostate cancer, it will probably shorten your life if it is not caught early. But if you are older or in poor health, then prostate cancer may never become a major problem because it often grows so slowly.

What the American Cancer Society recommends

The American Cancer Society recommends that men have a chance to make an informed decision with their health care provider about whether to be screened for prostate cancer. They should first get information about what is known and what is not known about the risks and possible benefits of prostate cancer screening. Men should not be screened unless they have received this information.

The talk about screening should take place at age 50 for men who are at average risk of prostate cancer..

This talk should take place starting at age 45 for men at high risk of getting prostate cancer. This includes African American men and men who have a father, brother, or son found to have prostate cancer at an early age (younger than age 65).

This talk should take place at age 40 for men at even higher risk (those with several family members-- father, brother, son) who had prostate cancer at an early age).

If, after this talk, a man is not able to decide whether testing is right for him, the screening decision can be made by the health care provider, who should take into account the patient’s overall health and values.

Men who choose to be tested and who have a PSA of less than 2.5 ng/ml (see below), may only need to be retested every 2 years.

Screening should be done yearly for men whose PSA level is 2.5 ng/ml or higher.

Because prostate cancer grows slowly, those men without symptoms of prostate cancer who aren't likely to live 10 more years should not be offered testing since they are not likely to benefit.

Even after a decision about testing has been made, men and their doctors should keep on talking about the pros and cons of testing as new information about the benefits and risks of testing becomes known. The patient's health, values, and choices can change as well.

The PSA blood test

PSA (prostate-specific antigen) is a substance made by the prostate gland. Although PSA is mostly found in semen, a small amount is also found in the blood. Most healthy men have levels under 4 ng/mL (nanograms per milliliter) of blood. The chance of having prostate cancer goes up as the PSA level goes up. If your level is between 4 and 10, you have about a 1 in 4 chance of having prostate cancer. If it is above 10, your chance is over 50%. But some men with a PSA below 4 can also have prostate cancer.

Factors other than cancer can also cause the PSA level to go up, including:

• An enlarged prostate like BPH (benign prostatic hyperplasia--not cancer), that many men get as they grow older.
• Age: PSA levels go up slowly as you get older, even if you have no prostate changes.
• Infection or inflammation of the prostate gland (prostatitis).
• Ejaculation can cause the PSA to go up for a short time, and then go down again.
• Riding a bicycle
• Certain urology tests

Some things can cause PSA levels to go down, even when cancer is present:

• Certain medicines used to treat BPH or urinary symptoms. You should tell your doctor if you are taking medicines for these problems, because the doctor will need to adjust the reading.
• Some herbal mixtures that are sold as dietary supplements may also hide a high PSA level. This is why it is important to let your doctor know if you are taking any type of supplement--even ones not meant for prostate health. Saw palmetto (an herb used by some men to treat BPH) does not seem to affect the measurement of PSA.
• Obesity: Very overweight men tend to have lower PSA levels.
• Aspirin: Men taking aspirin regularly tend to have lower PSA levels. This effect is most pronounced in non-smokers.

There are a number of new types of PSA tests that might help to show whether or not you need more testing. Not all doctors agree on how to use these new PSA tests. You should talk to your doctor about your cancer risk and any tests that you are having.

Use of the PSA blood test after prostate cancer has been found

Although the PSA test is used mainly to find prostate cancer early, it has other uses, too.

• In men diagnosed with prostate cancer, it can be used along with other results to help decide which types of tests are needed.
• A very high PSA level might mean that the cancer has spread beyond the prostate. This also helps determine treatment because some forms of treatment are not as helpful for cancer that has spread to the lymph nodes or other organs.
• The PSA test can also be used to help show if treatment is working, how well it is working, or whether the cancer has come back after treatment.
• If you choose a "watchful waiting" approach, the PSA level can be used to help decide if the cancer is growing and whether you should think about starting treatment.
• If you are having hormone therapy or chemo, the PSA level can help tell how well the treatment is working or when it may be time to try a different form of treatment.

If prostate cancer has come back (recurred) after treatment, or if it has spread outside of the prostate (metastatic disease), the actual PSA number may not be as important as whether it changes and how quickly it changes. The PSA number does not tell whether or not a man will have symptoms or how long he will live. Many people have very high PSA values and feel just fine. Other men have low values and have symptoms.

DRE (digital rectal exam)

To do the DRE, the doctor puts a gloved, lubricated finger into the rectum to feel for any irregular or firm areas that might be cancer. The prostate gland is next to the rectum, and most cancers begin in the part of the gland that can be reached by rectal exam. The exam is uncomfortable, but it isn't painful and takes only a short time. It is more uncomfortable in men who have hemorrhoids.

The DRE is less effective than the PSA blood test in finding prostate cancer, but it can sometimes find cancers in men with normal PSA levels. For this reason, it may be done as a part of prostate cancer screening. The DRE is also used once a man is known to have prostate cancer. It can help tell whether the cancer has spread beyond his prostate gland. It can also be used to find cancer that has come back after treatment.

Transrectal ultrasound (TRUS)

Transrectal ultrasound (TRUS) uses sound waves to make a picture of the prostate on a video screen. For this test, a small probe is placed in the rectum. It gives off sound waves, which enter the prostate and create echoes that are picked up by the probe. A computer turns the pattern of echoes into a black and white picture of the prostate.

The test takes only a few minutes. You will feel some pressure when the TRUS probe is placed in your rectum, but it is usually not painful. TRUS is usually not used as a screening test for prostate cancer because it doesn't often show early cancer. It is most often used during a prostate biopsy to guide the biopsy needles into the right area of the prostate.

TRUS is used for other things as well. It can be used to measure the size of the prostate gland, which can help the doctor interpret the PSA level. It may also affect which treatment options a man has. It is also used as a guide during some forms of treatment such as cryosurgery (discussed in the Treatment section).

If cancer is suspected

Signs and symptoms of prostate cancer

Early prostate cancer often causes no symptoms. It may be found by a PSA test or DRE. Problems with urinating could be a sign of advanced prostate cancer, but more often this problem is caused by a less serious disease known as BPH (benign prostatic hyperplasia).

Symptoms of advanced prostate cancer are:

• Trouble having or keeping an erection (impotence)
• Blood in the urine
• Pain in the spine, hips, ribs, or other bones
• Weakness or numbness in the legs or feet
• Loss of bladder or bowel control

Once again, other diseases also can cause these symptoms.

If certain symptoms or the results of early tests suggest you might have prostate cancer, your doctor will do a prostate biopsy to find out whether the disease is present.

The prostate biopsy

A biopsy is the only way to know for sure if you have prostate cancer. During a biopsy, tissue from the prostate is removed so it can be sent to the lab to see if it contains cancer cells. A core needle biopsy is the type of biopsy used most often. Here is how it's done:

A small probe is placed in the rectum. The probe gives off sound waves which make a picture of the prostate on a video screen. This technique is called TRUS (transrectal ultrasound). Guided by TRUS, the doctor puts a thin needle through the wall of the rectum into the prostate gland. When the needle is pulled out, it takes out a piece of tissue, usually about ½ inch long and 1/16 inch across. This is done from 8 to18 times, but most doctors will take about 12 samples. Samples are often taken from different parts of the prostate. Ask your doctor how many samples will be taken. Some doctors do the biopsy through the skin between the rectum and the scrotum.

Although the test sounds painful, it usually causes little discomfort because it is done very quickly. The doctor can numb the area ahead of time. You might want to ask your doctor about doing this.

The biopsy takes about 10 minutes and is usually done in the doctor's office. You will likely be given antibiotics to take ahead of time and afterwards to reduce the chance of infection. For a few days afterwards you may notice some soreness, rust-colored urine, or light bleeding from the rectum. Many men also see some blood in their semen or have rust colored semen, which can last for several weeks after the biopsy.

Cancer may only be present in a small area of the prostate. Because of this, sometimes the biopsy will miss the cancer even when it is there. This is known as a "false negative." If your biopsy doesn't show cancer, but your doctor still strongly suspects cancer, a repeat biopsy may be needed.

Grading the prostate cancer

The biopsy sample will be sent to a lab. A doctor there will look for cancer cells in the sample. If cancer is present, the sample will be graded. Grading the cancer helps to predict how fast the cancer is likely to grow and spread.

Prostate cancers are graded on the basis of how closely the cells in the sample look like normal prostate cells. Those that look very different from normal cells are likely to mean a cancer that grows faster. The system used most often for grading prostate cancer is called the Gleason system.

Samples from 2 areas of the prostate are each graded from 1 to 5, and the number grades are added to give a Gleason score or sum of between 2 and 10. The lower the number, the more the cells in the sample look like normal prostate cells. A higher score means the cells look less normal and the cancer is likely to grow more quickly. Ask your doctor to explain the grade of your cancer because it is an important factor in making treatment decisions.

Sometimes the cells don't look like cancer but they don't look really normal either. In these cases, more biopsies may be done later.

Other things you may see on a biopsy report

The biopsy report tells you the grade of the cancer (if it is present), but it also often provides other information that may give a better idea of the scope of the cancer. These can include:

• The number of biopsy samples that contain cancer (for example, "7 out of 12")
• The amount of cancer in each of the cores (given as a percentage)
• Whether the cancer is on one side (left or right) of the prostate or both sides (bilateral)