[Screening for cancer of the prostate using prostate-specific antigen]

Systematic screening for prostate cancer was carried out in 600 men over 50 years of age by the industrial medicine departments of four big companies in the Paris region. The exploratory methods included prostate specific antigen (PSA) and prostatic acid phosphatase (PAP) assays, rectal palpation and two-dimensional transrectal ultrasonography. Biopsy of the prostate was performed either when the PSA level was above 5 ng/ml or when rectal palpation gave suspicious results, or when ultrasonography showed abnormal images. A total of 93 biopsies were performed, and 18 cases of cancer were detected. Eleven of these 18 patients underwent radical prostatectomy. The PSA assay, with an accepted limit of 5 ng/ml, detected 17 out of 18 cancers but was not very specific. The PAP assay had low sensitivity (only 5 positive results). Combined PAP assay and rectal palpation provided high sensitivity and good specificity. Transrectal ultrasonography was helpful only to determine the site of biopsy and the distribution of the lesions.