Free PSA is a Better Tumor Marker than Serum Total PSA in Diagnosis of Prostatic Carcinoma

Abstract

Estimation of serum prostate specific antigen (PSA) has been considered as valuable noninvasive biochemical diagnostic tool for early detection of prostatic carcinoma. This cross sectional purposive study was carried out to compare the performance of serum total PSA and free PSA in terms of their sensitivity, specificity and overall diagnostic accuracy for prostatic carcinoma among clinically suspected cases. This study included a total of fifty (50) DRE (digital rectal examination) positive patients admitted in Rajshahi Medical College Hospital (RMCH) and Private hospitals in Rajshahi city during the period of January, 2006 to January, 2008. Estimation of serum total PSA and free PSA were done by ELISA (Enzyme linked immunosorbent assay) method using commercially available kits and histopathological examination of the surgically resected prostatic tissue was done for laboratory confirmation of the diagnosis of prostatic carcinoma for all patients. Diagnostic sensitivities, specificities and overall accuracy of serum total PSA and free PSA were calculated using standard formulae against histopathological diagnosis. Prostatic carcinoma was detected by histopathological examination in 41 cases out of 50 patients with the mean age of 71.2 ± 10.1 years. The sensitivity, specificity and overall diagnostic accuracy of serum total PSA (at cut off value of ≥10 ng/ml) were found to be 80.48%, 88.90% and 82.00% respectively while they were 92.68%, 77.80% and 90.00% respectively for serum percent free PSA (at cut off value of ≤25%). It is inferred that percent free PSA is a better tumor marker than serum total PSA in the diagnosis of prostate carcinoma.

Role of Hyperinsulinemia in Increased Risk of Prostate Cancer: A Case Control Study from Kathmandu Valley

“…Estimation of PSA was performed by ELISA reader for all cases and controls. The standard procedure was followed as per manufacturer's instructions for ELISA (Asafudullah et al, 2011). Estimation of total cholesterol was done by CHOD-PAP method .…”

The Role of Free Prostate-Specific Antigen in the Diagnosis of Prostate Carcinoma: A Cross-Sectional Study in Rajshahi, Bangladesh

“…PSA measurement is a non-invasive diagnostic technique for early identification of prostatic cancer. For the diagnosis of prostate cancer, percent fPSA is preferred over tPSA (Asafudullah et al 2009). For better prostate cancer screening and future research, the study's purpose was to see the role of fPSA and f/t PSA in correctly identify prostate cancer versus BPH and reduce needless biopsies.…”

Specific Probe Selection from Landscape Phage Display Library and Its Application in Enzyme-Linked Immunosorbent Assay of Free Prostate-Specific Antigen

“…In addition, the ratio of f-PSA/t-PSA is an available index to improve the diagnostic certainty. − Thus, the detection of t-PSA and f-PSA plays an important role in the early diagnosis of prostate cancer. PSA is detected by immunoassay, radioimmunoassay, enzyme-linked immunosorbent assay (ELISA), electrochemiluminescence immunoassay (ECLIA), − time-resolved immunofluorometric assay with nanoparticle labeling, nanoparticle-based biobar code, multitumor markers protein chip, and surface plasmon resonance , due to their high sensitivity, specificity, and reproducibility. However, a simple, stable, and inexpensive approach for rapid f-PSA detection is highly requested.…”