Serum free prostate specific antigen and prostate specific antigen density measurements for predicting cancer in men with prior negative prostatic biopsies.

PURPOSE We examined the usefulness of measurements of free prostate specific antigen (PSA) and PSA density for predicting prostate cancer in men who had had a prior negative biopsy, a serum PSA level of 4.1 to 10.0 ng./ml. and benign findings on prostate examination. MATERIALS AND METHODS We measured percent free serum PSA and PSA density in 163 male volunteers age 50 years or older who were advised to have repeat prostatic biopsies for a serum PSA level of 4.1 to 10.0 ng./ml. RESULTS Of 99 men who had repeat biopsies 20 (20%) had prostate cancer detected. Prostate cancer was significantly associated with lower free PSA level and higher PSA density, with overlap in 83% of the cases. The use of percent free PSA cutoffs of 28 and 30% would have detected 90 and 95% of cancers, respectively, and avoided 13 and 12% of the biopsies, respectively. PSA density cutoffs of 0.10 and 0.08 would have detected 90 and 95% of cancers, respectively, and avoided 31 and 12% of biopsies, respectively. CONCLUSIONS Free PSA and PSA density predict prostate cancer in men who have had prior negative prostatic biopsies, serum PSA levels of 4.1 to 10.0 ng./ml. and a benign prostate examination. Both parameters may be used to avoid unnecessary biopsies with an acceptable decrease in sensitivity. Further studies are needed to determine cutoffs to be used in clinical practice.

[1]  W. Catalona,et al.  Detection of organ-confined prostate cancer is increased through prostate-specific antigen-based screening. , 1993, JAMA.

[2]  M. Brawer,et al.  Measurement of the proportion of free to total prostate-specific antigen improves diagnostic performance of prostate-specific antigen in the diagnostic gray zone of total prostate-specific antigen. , 1995, Urology.

[3]  W. Catalona,et al.  Serial prostatic biopsies in men with persistently elevated serum prostate specific antigen values. , 1994, The Journal of urology.

[4]  E. Leifer,et al.  Prospective use of free prostate-specific antigen to avoid repeat prostate biopsies in men with elevated total prostate-specific antigen. , 1996, Urology.

[5]  W. Catalona,et al.  Racial differences in a prostate cancer screening study. , 1996, The Journal of urology.

[6]  W. Catalona,et al.  Prostate specific antigen density versus prostate specific antigen slope as predictors of prostate cancer in men with initially negative prostatic biopsies. , 1996, The Journal of urology.

[7]  P. Knekt,et al.  Serum concentrations of prostate specific antigen and its complex with α1-antichymotrypsin before diagnosis of prostate cancer , 1994, The Lancet.

[8]  M M Elhilali,et al.  Reassessment of nonplanimetric transrectal ultrasound prostate volume estimates. , 1996, Urology.

[9]  David W. Hosmer,et al.  Applied Logistic Regression , 1991 .

[10]  W. Catalona,et al.  Evaluation of percentage of free serum prostate-specific antigen to improve specificity of prostate cancer screening. , 1995, JAMA.

[11]  W. Catalona,et al.  Measurement of prostate-specific antigen in serum as a screening test for prostate cancer. , 1991, The New England journal of medicine.