Population-based screening for prostate cancer by measuring total serum prostate-specific antigen in Iran

Abstract

Objective: To report the results from an Iranian large population-based randomized study of screening using prostate-specific antigen (PSA) to detect prostate cancer.

Materials and methods: A total of 3758 Iranian men older than 40 years were mass checked by PSA-based screening. Men with an abnormal digital rectal examination (DRE) and serum total PSA level of greater than 4 ng/mL, underwent transrectal ultrasonography (TRUS)-guided extended prostate biopsy.

Results: The PSA value (mean +/- standard deviation, SD) in all men without prostate cancer was 1.6 +/- 1.1 ng/mL and in those with cancer 18 +/- 44.8 ng/mL (P = 0.001). PSA values increased with age. In those aged 40-49, 50-59, 60-69 and > or = 70 years, the mean +/- SD PSA values were 1.3 +/- 0.7, 1.4 +/- 0.8, 1.8 +/- 1 and 2.2 +/- 1.6 ng/mL, respectively. Among the screened men, 323 (8.6%) had a serum PSA concentration greater than 4 ng/mL. Of patients who underwent prostate biopsy (230, 71.2%), 129 (positive predictive value, 56.1%) had prostate cancer. Additionally, nine cancers were detected among 16 patients with PSA of less than 4 ng/mL who had a doubtful DRE finding. The overall cancer detection rate was 3.6%; 1.4% at 40-49, 1.6% at 50-59, 4.2% at 60-69 and 12.9% at >/=70 years. Conventional systematic sextant biopsies, which accounted for six of the 10 cores in our biopsy scheme, detected 98 (71%) of the cancers.

Conclusions: The Iranian male population develops prostate cancer quite commonly if their serum PSA levels are greater than 4.0 ng/mL. In this study, 65.9% of the detected cancers were clinically significant. The conventional systematic sextant technique may be inappropriate for detection of all prostate cancers. The results need to be confirmed in other randomized trials.