COMPARISON OF DIFFERENT PROSTATE-SPECIFIC ANTIGEN CUTPOINTS FOR EARLYDETECTION OF PROSTATE-CANCER - RESULTS OF A LARGE SCREENING STUDY

Objectives. This study was designed to compare the usefulness of the n ormal prostate-specific antigen (PSA) level and the age-referenced PSA level in a large screening study for early detection of prostate canc er. Methods. A total of 21,078 subjects (aged 45 to 75 years) were par ticipants in a 1-year prostate cancer screening project with PSA as th e initial test. Of the volunteers, 1618 (8%) showed an elevated PSA le vel according to age-specific reference ranges, and using the normal P SA cutoff point (4.0 ng/mL), 1872 (9%) had elevated PSA levels between 4.0 and 6.5 ng/mL. Results. Biopsies in both groups were performed if the PSA level was elevated. We evaluated the effect on biopsy rate an d cancer detection. A PSA cutoff point of 2.5 ng/mL in men 45 to 49 ye ars old and a PSA cutoff point of 3.5 ng/mL in men 50 to 59 years old with normal digital rectal examination findings resulted in an 8% incr ease in the number of biopsies (66 of 778) and an 8% increase in organ -confined cancer detection. An increasing cutoff of 4.5 ng/mL in men 6 0 to 69 years old and 6.5 ng/mL in men 70 to 75 years old resulted in 21% fewer biopsies (205 of 985) and would have missed 4% of organ-conf ined tumors (8 of 220). Conclusions. We conclude that the use of PSA a ge-specific reference ranges increases the detection of clinically imp ortant and organ-confined cancers in young men and decreases the numbe r of biopsies in older men.