Perception of abnormal serum prostate-specific antigen (PSA) test results amongst family practitioners

With increased use of serum prostate-specific antigen (PSA) testing, prostate cancers are diagnosed at an earlier stage in younger men, when radical curative treatments are appropriate. Modifications of the PSA test such as PSA velocity and age-adjusted values are available to aid in the selection of patients for biopsy. However, it is not clear whether these data are used in general practice.

A self-administered questionnaire was mailed to all primary care practices within one region in the UK. A series of visual analogue questions designed to identify referral thresholds for age-adjusted PSA levels and PSA velocity were used to identify patterns in referral behaviour.

Individual family practitioners see only small numbers of patients requesting PSA tests or with newly diagnosed prostate cancer each year. The median (range) thresholds considered for referral at ages 45, 55, 65, 75 and 85 years were 4.5 ng/ml (2.5-15.5 ng/ml), 5.5 ng/ml (3.0-15.5 ng/ml), 6.5 ng/ml (3.5-15.5 ng/ml), 6.5 ng/ml (3.5-25.5 ng/ml), and 7.5 ng/ml (3.5-25.5 ng/ml), respectively. Only 5% of practitioners correctly identified the age-specific PSA threshold for referral of a 45-year-old man.

It is important to remember that younger men (even those in their forties and fifties) may be at risk of prostate cancer even if asymptomatic. It is important in a climate of increasing demand for PSA testing that those who initiate the process understand the implications and limitations of testing, including appropriate triggers for referral to secondary care. The exact approach required for the successful dissemination of this information to primary care is not clear, but our data suggest that a better understanding is required.