Prostate cancer is one of the most common cancers in the United States. It is a cancer of the prostate gland, which is only found in men. This gland sits below the bladder. In most cases, men with prostate cancer are over 65 years of age, but it can occur in younger men.
In its early stages, prostate cancer has no symptoms. It is often a slow-growing cancer. In fact, it may take years to develop. As the cancer gets larger or spreads, it may cause problems. This may include impotence , urinary problems, and pain in your back, hip, or thighs. To help detect cancer in its early stages, your doctor may recommend a prostate specific antigen test (PSA) and a digital rectal exam (DRE).
The United States Preventive Services Task Force (USPSTF) and the American Academy of Family Physicians (AAFP) do not recommend PSA tests to screen for prostate cancer in men of any age. Other organizations, such as the American Urological Association, recommend that it be a decision a man can make after discussing the risks and benefits with his doctor. The changes made to screening guidelines in 2012 led to controversy, especially since the PSA test was widely used to screen for cancer. Take the approach that you feel most comfortable with. It is important to know your history, your family's history, your risk, and your comfort level.
PSA is made by the prostate gland. A PSA test measures the level of the antigen in your blood. It is done with a sample of blood, which can be taken at your doctor’s office during a regular physical exam. It is normal for healthy males to have some PSA in their blood. Levels sometimes increase when prostate cancer is present. There are other conditions which may increase the PSA. They include an prostatitis or benign prostatic hypertrophy (BPH). BPH is a benign (non-cancerous) prostate enlargement. It is often found in older men. If your PSA increases, your doctor may order further tests.
PSA may also be checked in people who have already been diagnosed with cancer. PSA may be used to check the progress of cancer or to evaluate treatment.
- Both benign and cancerous conditions can cause elevated PSA levels.
- The blood test can only measure the levels, not the cause. Further testing would need to be done to find the cause.
- Prostate cancer does not always increase PSA levels. A test that shows normal levels does not mean you are cancer-free. Do not ignore symptoms common to prostate cancer because you had a normal PSA test. This could lead to a delay in treatment.
Digital Rectal Exam
The digital rectal exam (DRE) may be done during a routine physical exam. The prostate gland lies next to the rectal wall. Normally, the prostate is roughly the size of a walnut. The doctor will use a gloved finger to feel the prostate through the rectum. This exam is done to find lumps or changes to the prostate gland.
- The DRE may not be able to determine if the lump is cancerous or not. A positive test will lead to further testing.
- Some lumps may not be found through this exam. Very early stage cancer is difficult to detect with DRE. A clear test (where the doctor does not detect any lumps) may again encourage men to ignore symptoms common to prostate cancer. This could lead to delays in treatment.
Based on the results of one or both tests, your doctor may recommend a prostate biopsy. A needle is used to remove a sample of the prostate. The sample will then be examined under a microscope for cancer cells. A biopsy is the only way to confirm the presence of cancer.
A biopsy does have some degree of risk. It can lead to problems with bleeding or infections. A biopsy can also be an uncomfortable process.
Since the increased PSA levels do not always mean cancer, some men will end up with unnecessary biopsies. Undergoing any exam for cancer can be a stressful process. For some people, though, identifying cancer at an early stage can be a life-saving step.
Most prostate cancers are slow-growing. Some are so slow that men with prostate cancer often die from other causes without knowing they had it. Your age, cancer risk factors, DRE, and PSA results will all play a role in treatment decisions. One option is to simply wait and monitor changes in the cancer. The PSA levels can be used to track any changes.
Some may be uncomfortable with having untreated cancer. However, cancer treatments have risks of their own. Treatments may cause impotence or trouble with leakage of urine.
The benefit of a screening test is measured through its ability to save lives. While prostate cancer screening remains a controversial issue, a large trial involving 20,000 men found that PSA screening did reduce the death rate from prostate cancer. However, many other studies have not shown this connection. Also, research has failed so far to show a link between prostate cancer screening and lower overall mortality in men.
If you are aged 50 years or older, PSA and DRE tests may be offered to you. If you are at high risk for prostate cancer, screening can start even earlier. Talk to your doctor about the test options. Ask about the benefits and risks of prostate screening for you. Life expectancy, family history, age, and current health will all play a role in your screening plan for prostate cancer.
- Reviewer: Michael Woods, MD
- Review Date: 10/2015 -
- Update Date: 11/05/2015 -