PROSTATE CARCINOMA SCREENING IN THE COUNTY OF TYROL, AUSTRIA - EXPERIENCE AND RESULTS

BACKGROUND. This article summarizes the experience and results of diff erent prostate carcinoma screening projects using total prostate speci fic antigen (PSA) as the initial test and different diagnostic tests t o improve specificity. METHODS. The seven projects studied included 1) a mass screening study using PSA as the initial test in 21,079 volunt eers; 2) an investigation of the usefulness of normal and age-referenc ed PSA cutoffs in 1618 men; 3) a PSA-based screening study of 2272 asy mptomatic blood donors; 4) an investigation of the incidence and clini cal significance of transitional zone carcinoma in 340 men with negati ve rectal examination findings and clearly visible prostatic zones on three-dimensional transrectal ultrasound; 5) determination of percent free PSA in one retrospective and two prospective screening studies to define the optimal range of total PSA and determine the appropriate c utpoints for percent free PSA within this range; 6) evaluation of the diagnostic benefit of PSA transitional zone density in 308 screening v olunteers; and 7) a study of the impact of PSA-based screening on the percentage of incidental prostate carcinoma diagnosed in 1543 men unde rgoing transurethral resection of the prostate. RESULTS. 1) Of the 21, 078 volunteers, 1618 (8%) had elevated PSA levels. Of these men, 778 ( 48%) underwent biopsies; 197 biopsies (25%) were positive for prostate carcinoma and 135 patients underwent radical prostatectomy. Ninety-fi ve of the 135 pathologically staged lesions (70%) were found to be org an-confined. 2) A PSA cutoff of 2.5 ng/mL in men age 45-49 years and o f 3.5 ng/mL in men age 50-59 years with normal digital rectal examinat ion findings resulted in an 8% increase in both the number of biopsies (66 of 778) and the detection rate of organ-confined disease. 3) Of t he 2272 men, 284 had elevated PSA levels and prostate carcinoma was de tected in 62 men. AU patients underwent radical prostatectomy and hist ologic examination revealed organ-confined disease in all but eight me n. 4) Ninety-eight of 340 men (28.8%) had biopsies positive for carcin oma; 28 of these patients (28.5%) had carcinoma that originated in the transitional zone only. 5) in the retrospective study, receiver opera ting characteristic curve analysis showed that by using a percent free PSA of 18% as a biopsy criterion in men with an elevated PSA serum le vel, 37% of the negative biopsies could be eliminated although 94% of all carcinomas would still be detected. In the first prospective study , 106 of 158 men with elevated total PSA values between 2.5 and 10.0 n g/mL were further evaluated and 37 prostate carcinomas were detected. By using a percent free PSA of less than or equal to 22% as a biopsy c riterion, 30% of the negative biopsies could be eliminated although 98 % of the carcinomas would still be detected. In the second prospective study, 120 of 465 men with total PSA levels between 1.25 and 6.49 ng/ mL, a percent free PSA of <18%, and normal digital rectal examination findings were further evaluated and 27 (22.5%) were found to have pros tate carcinoma. 6) Receiver operating-characteristic curve analysis fo r PSA transitional zone density showed that by using a PSA transitiona l zone density of >0.22 ng/mL/cc as a biopsy criterion, 24.4% of negat ive biopsies could be avoided without missing the detection of a singl e carcinoma. 7) In the prescreening era the incidence of T1a Grade 1 a nd 2 carcinomas was 3.1% and the incidence of T1a Grade 3 and T1b carc inoma was 2.3%, whereas in the years after the establishment of PSA-ba sed screening the incidence was 4.6% and 1.03%, respectively. CONCLUSI ONS. These data suggest that PSA-based screening increases the detecti on rate of clinically significant and organ-confined tumors. Percent f ree PSA and PSA transitional zone density provide an additional diagno stic benefit over total PSA. (C) 1997 American Cancer Society.