Clinical Health Updates

Prostate CA relatively common even with PSA < 4.0

Clinical Question:
How common is prostate cancer among men with a prostate-specific antigen level of less than or equal to 4.0 ng/mL?

Bottom Line:
Prostate cancer, even high-grade disease, is found in older men with a so-called normal prostate-specific antigen (PSA) result. Biopsy-detected prostate cancer, including high-grade cancers, is not rare among men with PSA levels of 4.0 ng per milliliter or less–levels generally thought to be in the normal range. It is wise to remember that although prostate cancer occurs in 17% of men, it only kills approximately 3% of them. It is wise to be cautious about working up “abnormal” PSA tests, and very hesitant about biopsying men with a PSA <= 4.0 ng/mL.

Reference:
Thompson IM, Pauler DK, Goodman PJ, et al. Prevalence of prostate cancer among men with a prostate-specific antigen level <= 4.0 ng per milliliter. N Engl J Med 2004; 350:2239-246.

Study Design:
Cohort (prospective)

Synopsis:
The optimal upper limit of the normal range for prostate-specific antigen (PSA) is unknown. The authors investigated the prevalence of prostate cancer among men in the Prostate Cancer Prevention Trial who had a PSA level of 4.0 ng per milliliter or less. Of 18,882 men enrolled in the prevention trial, 9459 were randomly assigned to receive placebo and had an annual measurement of PSA and a digital rectal examination. Among these 9459 men, 2950 men never had a PSA level of more than 4.0 ng per milliliter or an abnormal digital rectal examination, had a final PSA determination, and underwent a prostate biopsy after being in the study for seven years. Among the 2950 men (age range, 62 to 91 years), prostate cancer was diagnosed in 449 (15.2 percent); 67 of these 449 cancers (14.9 percent) had a Gleason score of 7 or higher. The prevalence of prostate cancer was 6.6 percent among men with a PSA level of up to 0.5 ng per milliliter, 10.1 percent among those with values of 0.6 to 1.0 ng per milliliter, 17.0 percent among those with values of 1.1 to 2.0 ng per milliliter, 23.9 percent among those with values of 2.1 to 3.0 ng per milliliter, and 26.9 percent among those with values of 3.1 to 4.0 ng per milliliter. The prevalence of high-grade cancers increased from 12.5 percent of cancers associated with a PSA level of 0.5 ng per milliliter or less to 25.0 percent of cancers associated with a PSA level of 3.1 to 4.0 ng per milliliter.