Evaluation of prostate specific antigen acceleration for prostate cancer diagnosis.

Abstract

PURPOSE: Prostate specific antigen acceleration can be calculated as the slope of log prostate specific antigen vs time, where log is the natural logarithm. We determined the best interval in which prostate specific antigen acceleration can be calculated with the best result in terms of specificity and sensitivity for prostate cancer diagnosis. MATERIALS AND METHODS: Entered in the study were 741 men who underwent transrectal ultrasound guided prostate biopsy with 12 or more cores and at least 3 prior consecutive prostate specific antigen measurements in at least 365 days. Prostate specific antigen acceleration was calculated as the slope of log prostate specific antigen vs time using a minimum of 3 prostate specific antigen measurements. Acceleration was evaluated at different intervals, including within 1 year (365 days), 2 years (730 days), 3 years (1,095 days), 4 years (1,460 days), 5 years (1,825 days) and 6 years (2,190 days) before the last measurement. RESULTS: A total of 255 cancers (34.4%) were found. On ROC analysis the AUC of prostate specific antigen acceleration (0.728, 95% CI 0.694-0.760) was better than that of prostate specific antigen, prostate specific antigen velocity and prostate specific antigen doubling time. The highest AUC of prostate specific antigen kinetics was for prostate specific antigen acceleration calculated within 3 to 4 years (731 to 1,460 days) before the last measurement. CONCLUSIONS: Three or more prostate specific antigen measurements within 3 to 4 years (731 to 1,460 days) before the last measurement enabled more accurate calculation of prostate specific antigen acceleration than measurement within 1 to 2 years (0 to 730 days).