Prostate Cancer (cont.)
Why is Prostate Cancer Screening Important?
Although currently controversial, most urologists would recommend regular screening for prostate cancer using PSA and DRE in men who are likely to live more than 10 years (for example, life expectancy >10 years).
- Elevated prostate serum antigen (PSA): Although the PSA test is not useful to actually diagnose prostate cancer, it predicts the risk of prostate cancer being present. Currently, most prostate cancers are discovered when a prostate biopsy is performed after a raised serum prostate specific antigen (PSA) blood test is detected. A PSA test is usually performed as a part of a health screening program. However, its use as a screening method is controversial as there is no universally accepted threshold above which the PSA is considered abnormal. Raising the threshold value reduces the number of unnecessary biopsies, but increases the number of cancers that are missed. Lowering the threshold value reduces the number of cancers that are missed, but may lead to the detection of more cancers that will never become clinically significant.
- Abnormal digital rectal exam (DRE): Prostate cancers may be suspected with an abnormal prostate exam detected by digital rectal exam (DRE). A digital rectal exam is part of a thorough regular health examination. During DRE, the examiner inserts a gloved and lubricated finger (“digital” refers to finger) in the rectum to feel the back of the prostate for abnormalities. The exam may reveal asymmetry, swelling, tenderness, nodules, or irregular areas in the prostate. In contrast, symmetric enlargement and firmness of the prostate are more frequently seen in men with benign prostatic hyperplasia (BPH). A suspicious prostate exam prompts the physician to request a prostate biopsy to confirm or rule out the presence of prostate cancer (details regarding PSA and prostate biopsy are available in subsequent sections). This finger exam cannot detect all tumors of the prostate gland. About 25% to 30% of prostate tumors are located in areas of the gland that cannot be felt during digital rectal examination. Prostate cancer is found in approximately 30% of men with suspicious prostate examination.
- Elevated prostate cancer antigen 3 (PCA3): PCA3 is new test that may help to discriminate between cancer-related versus nonspecific PSA elevations. There is not enough data to determine if PCA3 is useful for prostate cancer screening, but it may help to determine the need for biopsy. Measuring PCA3 is done using a urine sample after a prostate massage.
- Screening is used for the detection of prostate cancer in men from the general population with no related symptoms. The purpose of screening is to detect and treat the disease earlier in order to reduce prostate cancer mortality.
- The decision to screen is a shared decision between the patient and the physician.
- The physician should discuss the benefits, risks, and limitations of prostate cancer screening with patients and then offer testing.
- The American Urological Association (AUA) issued their latest guidelines for prostate cancer in 2013. According to these guidelines, men at the age of 55-69 should be offered a baseline serum PSA test and a prostate exam (DRE) to ascertain the risk of prostate cancer. Subsequent screening and tests may be performed according to the findings on this initial evaluation and an individual's risk of getting the disease on the basis of other factors such as race, ethnicity, and family history of prostate cancer. Most urologists currently would advise some form of screening in men with life expectancy greater than 10 years. Most frequently, it would be performed on an annual basis.
- There is no universally accepted age limit after which screening should be stopped. AUA guidelines recommend that the decision on whether to screen in men age >75 years should be made on an individual basis.
Medically Reviewed by a Doctor on 3/31/2015
Pierre-Alain Hueber, MD, PhD
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