Free Prostate-specific Antigen Density Research Articles

Prostate cancer with elevated free prostate-specific antigen density: A case report

BACKGROUND Prostate cancer is the second most common cancer among men worldwide, and prostate-specific antigen (PSA) is often used in clinical practice to screen for prostate cancer. Normal total PSA (tPSA) level initially excludes prostate cancer. Here, we report a case of prostate cancer with elevated free PSA density (fPSAD). CASE SUMMARY A patient diagnosed with benign prostatic hyperplasia underwent prostatectomy, and the postoperative pathological results showed acinar adenocarcinoma of the prostate. The patient is currently undergoing endocrine chemotherapy. CONCLUSION We provide a clinical reference for diagnosis and treatment of patients with normal tPSA but elevated fPSAD.

The efficacy of the percent free prostate specific antigen density in screening for prostate cancer in patients with normal digital rectal examinations and intermediate prostate specific antigen levels

The efficacy of the percent free prostate specific antigen density in screening for prostate cancer in patients with normal digital rectal examinations and intermediate prostate specific antigen levels

Use of Percent Free Prostate-Specific Antigen Density to Improve the Specificity for Detecting Prostate Cancer in Patients with Normal Rectal Examinations and Intermediate Prostate-Specific Antigen Levels

Introduction: As prostatic volume influences percent free prostate-specific antigen (PSA) in patients with prostate cancer, we evaluated whether percent free PSA density, which relates the serum percent free PSA to the volume of the prostate determined by transrectal ultrasound, could increase the specificity of cancer detection in men with normal digital rectal examinations and intermediate PSA levels. Materials and Methods: We prospectively evaluated 105 consecutive men with normal digital rectal examinations and serum PSA levels of 4.1–10.0 ng/ml. All patients underwent at least sextant prostate biopsies to establish the diagnosis. For detection of total and free PSA we used an Immulite free and total PSA assay. We compared PSA density, percent free PSA and percent free PSA density for their utility in cancer detection. Results: Overall, 20 of 105 patients (19%) had prostate cancer. The area under the curve (AUC) for percent free PSA density was 0.771, not significantly higher than the AUC of 0.75 for PSA density (p = 0.778), but significantly higher than the AUC of 0.604 for percent free PSA (p = 0.021). Of these three parameters, percent free PSA density yielded the highest specificity percentage (54.1%) at 95% sensitivity. Conclusions: Percent free PSA density is more specific than percent free PSA in distinguishing benign from malignant disease in men with a normal digital rectal examination and an intermediate PSA level. Further study is necessary to discover whether percent free PSA density is superior to percent free PSA or PSA density.

Can Free and Total Prostate Specific Antigen and Prostatic Volume Distinguish Between Men With Negative and Positive Systematic Ultrasound Guided Prostate Biopsies?

We evaluated the role of free and total serum prostate specific antigen (PSA) and prostate volume in discriminating between men with negative and positive transrectal ultrasound guided biopsies. A total of 104 consecutive men with a positive biopsy and at least 3 mm. of prostate cancer was compared to 110 consecutive men with a negative biopsy. Prostate volume was determined by transrectal ultrasound. Total PSA was determined by the Tosoh AIA-600 PSA assay and free PSA was measured by the PSA II Dianon assay. We determined the free-to-total PSA ratio, free and total PSA densities, and the relationship of free PSA and free-to-total PSA ratio to prostate volume. Using a 23% cutoff value of free-to-total PSA, only 22.7% of biopsies were preventable in patients with a negative biopsy but 9.6% of the cancers were missed. At a total PSA of 4 to 10 ng./ml. 44.4% of the biopsy negative cases were correctly identified while missing 9.1% of the cancers if a 20% free PSA cutoff is used. For total PSA more than 10 ng./ml. an 18% free PSA cutoff properly identified 30.2% of the biopsy negative cases while missing 9.3% of the cancers. Percent free PSA is a better discriminant than prostate volume for total PSA more than 4 ng./ml. and the combination was not helpful. Free PSA density was identical in patients with negative and positive biopsies. There was no relationship between free PSA or free-to-total PSA ratio levels and prostate volume. Use of a single discriminant criterion of free-to-total PSA ratio in the practical clinical setting of distinguishing negative and positive biopsies appears useful in patients with a total PSA of 4 to 10 ng./ml. Since free PSA is unrelated to prostate volume in biopsy negative and positive cases the physiological basis of free PSA is an enigma.

Prospective use of free PSA to avoid repeat prostate biopsies in men with elevated total PSA

Prostate-specific antigen (PSA) is a most valuable tool for the early detection of prostate cancer; however, it has a high false-positive rate as presently used in prostate cancer screening programs. Patients with persistent PSA elevations, normal digital rectal examinations, and multiple negative biopsies present a clinical dilemma. We prospectively evaluated whether free PSA improves the specificity of PSA and can be useful as a clinical guide to avoid repeat prostate biopsies in a group of such patients. Sixty-seven men with persistent PSA elevations (mean 9.6 ng/mL; range 4.1-24.8 ng/mL), normal digital rectal examinations, and two or more prior sextant biopsies (mean 2.8), had serum collected for measurement of total and free PSA. All patients were rebiopsied to determine the receiver-operating characteristics (ROC) of total PSA vs. percent free PSA for prostate cancer detection. This study by biopsy identified 11 new prostate cancer cases. The median percent free PSA was significantly higher at 18.1% among men without prostate cancer, compared to 6.4% in men with prostate cancer (P < 0.00005). When sensitivity was plotted against I-specificity, the area under the receiver-operating curve (ROC) for percent free PSA was 0.95, compared to 0.75 for free PSA density, 0.59 for PSA density, and 0.54 for PSA. In patients with elevated total PSA levels, normal digital rectal examinations, and two prior sets of negative sextant prostate biopsies, a cutoff of 10% free PSA would maintain sensitivity at 91% with a corresponding specificity of 86%. Selective measurement of percent free PSA in cases of uncertain diagnosis can significantly improve the specificity of prostate cancer detection compared to total PSA alone. A low percent free PSA (< 10%) appears to be a significant predictor of prostate cancer even after two or more negative prostate biopsies.