Complexed Prostate Specific Antigen Provides Significant Enhancement of Specificity Compared With Total Prostate Specific Antigen for Detecting Prostate Cancer

Abstract

The measurement of complexed PSA represents an alternative to the use of percent free PSA, although the patient populations identified by the 2 tests are different.

Prostate-specific antigen testing accuracy in community practice

“…Areas under the ROC curve have been reported to range from 0.65 to 0.77 in case series comprised of patients enrolled in screening trials [4,19-21] or followed in urologic practice [22]. Among urologic studies, we found only Labrie and colleagues reporting a substantially higher area under the ROC curve: 0.88 (SE 0.03) [23].…”

“…In the urologic literature, sensitivities ranged from 67% to 90%, specificities ranged from 28% to 59%, and positive predictive values ranged from 30% to 43% [9-11,19,20,27,28]. However, almost all of the published studies, including our own, are flawed by potential work-up bias because men with elevated PSA levels were significantly more likely to be biopsied.…”

Antibacterial therapy improves the effectiveness of prostate cancer detection using prostate-specific antigen in patients with asymptomatic prostatitis

“…Kehinde et al [18] reported that only 18 (11.0%) of the 161 patients with PSA 10.0 ng/ml or greater were diagnosed with PC, and 33 (21.0%) of the patients were diagnosed with of prostatitis. Several PSA-related factors, including the f/t PSA, PSAD, and PSA velocity, have been examined in an attempt to improve the efficiency of prostate biopsies in patients who are within the PSA ''gray zone'' [19,20]. Karazanashvili and Managadze [6] reported that using the percentage of PSA change after antibacterial therapy improved the PC detection accuracy in chronic prostatitis patients with a baseline PSA of 4.0-10.0 ng/ml.…”

Improving the utility of prostate specific antigen (PSA) in the diagnosis of prostate cancer: the use of PSA derivatives and novel markers

“…Despite these theoretical advantages initial retrospective reports of the use of ACT complexed PSA showed no improvement in specificity compared to the use of the f/t PSA ratio. 36 Indeed one study surprisingly reported it to be of decreased utility. 37 Recently a prospective study has been reported and though the numbers were small (only 51 men with cancer) ACT complexed PSA did outperform f/t PSA ratio with a specificity of 24.8% compared with 17.4%, although this was not statistically significant.…”