Comparing Two Modalities of Screening for Prostate Cancer: Digital Rectal Examination + Transrectal Ultrasonography Vs. Prostate-Specific Antigen

Abstract

Aims and background

To evaluate the performance and feasibility of screening for prostate cancer by comparing screening modalities.

Methods

Prospective study of two comparable cohorts of healthy resident males aged 60 to 75 years. Screening attenders in the two invited cohorts were screened either by digital rectal examination (DRE) and transrectal ultrasonography (TRUS), or by serum prostate-specific antigen determination (PSA: cutoff 4 ng/ml). Attendance and biopsy rates, predictive values, prevalence of screen-detected cancers, as well as screening costs were determined, and the efficiency of the two screening modalities was compared.

Results

1425 subjects were screened by DRE + TRUS. Attendance rate was 33.7%, the biopsy rate was 2.7%, and the prevalence of detected cancers was 1.82%. A total of 1315 subjects was screened by PSA. Attendance rate was 66.9%, the biopsy rate was 2.8%, and the prevalence of detected cancers was 1.67%. Screen-detected cancer stage was more favorable than observed in clinical practice, and early detection was evident, with the prevalence/incidence ratio higher than 10:1 in both programs. The cost per subject screened was about 34,000 Lire for DRE + TRSU and about 30,000 Lire for PSA program.

Conclusions

The study confirms that early detection of prostate cancer is possible and that screening is practically feasible. Both screening modalities achieved comparable results as regards early detection, but screening by PSA had a higher compliance and lower costs. PSA seems the ideal test to be used in prospective controlled studies aimed at demonstrating screening efficacy.