Background: Measurements of PSA in serum is crucial in the diagnostic work-up of prostatic diseases.
Material and methods: We have studied the distribution of PSA values in an unselected population of 609 men, and the relation between PSA level and urinary symptoms, age and prostate volume.
Results: 87 (14%) men had a PSA concentration at or above the reference value of 4.0 ng/ml. Prostate cancer was verified in 14 (16%) of these men. The probability of having PSA equal to or above 4.0 ng/ml was 12 times greater for men with a prostate volume of 40 cm3 or less than for men with a prostate volume less than 20 cm3. Mean PSA values were higher in men with severe than with mild urinary symptoms, but symptoms were poor predictors of PSA levels. Age was not associated with an increase in PSA level independent of prostate volume.
Interpretation: Absence of urinary symptoms does not exclude elevated PSA values and thus not cancer. Most men with PSA equal to or above 10.0 ng/ml will have prostate cancer, but enlarged prostate without cancer can also give elevated PSA values.