Prostate Cancer Screening Guidelines

Several medical organizations, such as the American Cancer Society, issued prostate cancer early detection guidelines, which include two tests to screen men for prostate cancer. In the first, known as a digital rectal examination (DRE), a doctor inserts a gloved finger into the rectum to feel for lumps in the prostate. In the second, a blood test detects the amount of a protein called prostate-specific antigen (PSA) circulating in a man's blood. PSA is a good indicator of activity (such as cell division) in the gland. While an abnormal DRE and an elevated PSA level (greater than or equal to 4.0 ng/ml) may be indicators of prostate cancer, neither test alone or in combination can provide a definitive diagnosis of prostate cancer -- for this, a biopsy of the prostate is required. For example, men who have a common, noncancerous condition called benign prostatic hyperplasia (BPH) may also have elevated PSA levels.

Other medical organizations note that reliable studies have yet to show that early detection and treatment result in fewer deaths from prostate cancer. However, most experts agree that the introduction of early detection programs such as DRE and the PSA test have played a significant role over the past ten years in the increased number of prostate cancer patients being diagnosed at early stages. And a number of studies have shown that prostate cancers detected through screening are more often confined to the prostate gland, and thus more easily treated, than those detected by a DRE alone. Additionally, the recent decline in deaths from prostate cancer in the US may have been caused, in part, by the increase in early detection.

A recent study from Scandinavia that looked at about 700 men with prostate cancers confined to their prostate gland randomly assigned some of these men to receive a radical prostatectomy (in which the prostate and some tissue surrounding it are surgically removed) while others were assigned to the watchful waiting group (in which the cancer is closely watched and treatment is deferred). The results of the study showed that the men assigned to the prostatectomy group had a statistically significant increase in overall survival at ten years, documenting the overall benefit of radical prostatectomy in patients with localized prostate cancer.

A number of studies have shown that a PSA level above 4 ng/mL increases the chance that doctors will find prostate cancer when a biopsy is performed. Several other studies of men with PSA levels in the range of 2.5 to 4.0 ng/ml have shown that a substantial number of men in this group, regardless of age, will be diagnosed with prostate cancer when biopsied.

What are considered acceptable PSA levels change as a man ages. As a result, age-specific PSA reference ranges were introduced by doctors as a method to increase cancer detection in younger men by lowering the PSA values that trigger biopsy and to decrease unnecessary biopsies in older men by increasing PSA cutoffs. The concern is that by using this lower PSA-level threshold, it is possible that clinically insignificant or unimportant cancers, which would not require treatment, are being unnecessarily diagnosed. Overall, however, about 80 percent of cancers detected by PSA testing alone are biologically significant, meaning they require active treatment.

PSA levels commonly fluctuate above and below the normal range, even among healthy men. As a result, doctors prefer to look at the change in PSA values over time -- a measurement known as PSA velocity. A number of studies have concluded that tracking the rate of change in PSA levels over time can provide useful information and has increased specificity in detecting prostate cancer when compared to a single PSA measurement. Designed to better select men for prostate biopsy, PSA velocity test recommendations include collecting PSA levels over a period of no less than 18 months, using at least three readings to calculate PSA velocity. PSA velocity has been best used in younger men who have elected to begin early detection programs before the age of 50.

Our doctors recommend the following screening guidelines:

For men in the general population, prostate cancer screening -- using both PSA testing and a DRE -- should begin at age 50. In high-risk groups such as African-American men and men with a family history of prostate cancer, prostate cancer screening -- using both PSA testing and DRE -- should begin at age 40.

If a man screened with DRE receives an abnormal result, regardless of PSA level, he should be referred to a urologist for further testing.

To balance the influence of age on PSA levels, the following age-specific PSA level cut-offs should be considered:

• Greater than or equal to 2.5 ng/mL for men up to age 49
• Greater than or equal to 3.5 ng/mL for men aged 50 to 59
• Greater than or equal to 4.0 ng/mL for men aged 60 and older.

Men with values outside their age-allowed targets should be considered as candidates for prostate biopsy.

For those men being screened for PSA velocity, a PSA velocity of greater than or equal to 0.75 ng/mL per year should necessitate a prostate biopsy -- even if the PSA level is in the normal range.

Again, it is important to remember that the evidence supporting the usefulness of prostate cancer screening is suggestive but not definitive, and to note the potential harms (i.e. anxiety, biopsy complications) that may result from prostate cancer screening. As always, the subject of prostate cancer screening should be discussed with your physician.