What is cancer screening?
Cancer screening is the process of routinely checking for cancer when there are no symptoms. Screening for prostate cancer consists of the digital rectal exam and the prostate-specific antigen (PSA) test.
In a digital rectal exam, a doctor inserts a gloved finger into the rectum to feel for lumps or abnormalities in the prostate gland. The PSA test is a simple blood test that determines the level of PSA – a protein produced by the prostate gland – in the bloodstream.
The thinking in the medical community on the benefit of the PSA test has evolved. Even though the PSA test is often billed as a simple blood test that can detect cancer early and save men's lives, there is mixed evidence that the PSA test really does save lives. Opponents of the test argue that without a clear-cut benefit, screening isn't worth the risk because treatment carries a risk of serious side effects, such as impotence and incontinence.
What do the various medical organizations currently recommend regarding the PSA screening test?
- The American Cancer Society recommends that men discuss the need for a PSA test with their doctors at the following times:
- at age 50, if the man has an average risk of prostate cancer and can be expected to live at least another 10 years;
- at age 45, if the man has a high risk of prostate cancer. This includes African-Americans and men who have a first-degree relative (father, brother, or son) diagnosed with prostate cancer at an early age (younger than age 65).
- at age 40, if the man has a very high risk (more than one first-degree relative diagnosed with prostate cancer younger than 65).
If the man still cannot decide at this point, the physician should make the decision, taking into account all of these factors and the man's overall medical condition.
- The National Cancer Institute notes that a PSA test may have a "false positive" or "false negative" result. A false-positive result means that the PSA level is high, but the man does not actually have cancer.
As a result, he may have to have more tests that are unnecessary and may be harmful. A false-negative test means that even though the PSA level is low, the man actually does have cancer. The low PSA level may give him a false sense of security.
- The U.S. Preventive Services Task Force recommends against PSA-based screening for prostate cancer.
- The American Urological Association recommends against routine screening for men under the age of 55 who are at average risk; for men in this age group who are at higher risk, the decision to have a PSA test should be considered on a case-by-case basis. For men between the ages of 55 and 69, the recommendation is to discuss the PSA test with the physician, taking into account the man's overall medical condition and preferences.\
What should all men know about the current state of PSA testing? What issues should they discuss with their doctor?
- There is no lower limit of PSA below which the risk of cancer is zero.
- The PSA screen is inexact because both benign (non-cancerous) and malignant (cancerous) tissue can cause PSA levels to rise. In addition, certain medical conditions, such as prostatitis, urinary tract infections, and prostate enlargement, can also raise PSA levels. On the other hand, certain drugs can interfere with PSA testing and lower reported PSA levels.
- Because of these issues, a decision on whether to have a prostate biopsy should factor in many issues, including the patient’s age, comorbidities (other diseases), race, family history of prostate cancer, prior PSA values, and changes in PSA over time.
- Although a screening test may detect cancer, most cancers are slow-growing and may never threaten the life of a patient. Older patients may very well end up dying of another cause before the cancer caused any symptoms. Men in their 40s, on the other hand – who have long lives ahead of them, during which the cancer could grow and cause them to die – may decide to have regular PSA screening.
- Recent research has found that the higher a man's PSA level is when he is younger, the more likely he is to develop prostate cancer later in life. A PSA level in your 40s can predict your lifetime risk of cancer and help decide how often you should be screened.
- Men with a PSA of less than 2.0 at age 60 are unlikely to ever develop metastatic cancer or die from prostate can
Results and Follow-Up
The bottom line
For a small number of patients, screening offers a chance to catch aggressive cancers before it's too late. Therefore, for some men, the PSA screening test can be a lifesaver. At the same time, PSA screening causes thousands of men every year to have needless biopsies and other medical procedures that carry the risk of bleeding and infection, and cause unnecessary anxiety.
Further, screening leads to treatment of a lot of cancers that aren't life-threatening. In addition, all the treatments have side effects and may erode a man's quality of life.
You and your doctor must work together to make an informed decision on PSA testing. You and your doctor will review the pros and cons of the PSA screening test, your own risk factors for prostate disease, and your comfort level regarding cancer risk versus worries about treatment side effects.
If you do choose to have the PSA screening test, make sure you have it along with the digital rectal exam. Having both screening tests is the most likely way not to miss a cancer.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or healthcare provider. Please consult your healthcare provider for advice about a specific medical condition.
This document was last reviewed on: 08/28/2015