Document Type
Journal Article
Publisher
Elsevier BV
Place of Publication
Netherlands
School
School of Medical and Health Sciences
RAS ID
22637
Funders
Royal Brisbane and Women's Hospital Foundation (Ref: 2014002678)
Prostate Cancer Foundation of Australia
Cancer Council Queensland
Doctor in Training Research Scholarship - Avant Mutual Group Ltd
Cancer Council Queensland PhD Scholarship
Professor William Burnett Research Fellowship - Discipline of Surgery, School of Medicine, The University of Queensland
DVCR Strategic Initiative Funding from the University of Queensland (Grant No DVCR4480)
Abstract
Background
Prostate cancer (PCa) diagnosis requires improvement with the aid of more accurate biomarkers. Postejaculate urethral washings (PEUW) could be a physiological equivalent to urine obtained following rectal prostatic massage, the current basis for the prostate cancer antigen 3 (PCA3) test. The aim of this study was to investigate if PEUW contained prostate-based material, evidenced by the presence of prostate specific antigen (PSA), and to evaluate the diagnostic performance of PEUW-based biomarkers.
Methods
Male patients referred for elevated serum PSA or abnormal digital rectal examination provided ejaculate and PEUW samples. PSA, PCA3, and β2-microglobulin (β2M) were quantified in ejaculate and PEUW and compared with absolute and clinically significant (according to D'Amico criteria) PCa presence, as determined by biopsies. Diagnostic performance was determined and compared with serum PSA using receiver operating characteristic analysis.
Results
From 83 patients who provided PEUW samples, paired analysis with ejaculate samples was possible for 38 patients, while analysis in an unpaired, extended cohort was possible for 62 patients. PSA and PCA3 were detected in PEUW, normalized to β2M, and PCA3:PSA was calculated. In predicting absolute PCa status, PCA3:β2M in ejaculate [area under the curve (AUC) 0.717] and PEUW (AUC 0.569) were insignificantly better than PCA3:PSA (AUC 0.668 and 0.431, respectively) and comparable with serum PSA (AUC 0.617) with similar trends observed for the extended cohort. When considering clinically significant PCa presence, serum PSA in the comparison (AUC 0.640) and extended cohorts (AUC 0.665) was comparable with PCA3: β2M (AUC 0.667) and PCA3:PSA (AUC 0.605) in ejaculate, with lower estimates for PEUW in the comparison (PCA3: β2M AUC 0.496; PCA3:PSA AUC 0.342) and extended (PCA3: β2M AUC 0.497; PCA3:PSA AUC 0.469) cohorts. The statistical analysis was limited by sample size.
Conclusion
PEUW contains prostatic material, but has limited diagnostic accuracy when considering cell-derived DNA analysis. PCA3-based markers in ejaculate are comparable to serum PSA and digital rectal examination–urine markers.
DOI
10.1016/j.prnil.2016.04.002
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Comments
Roberts, M.J., Richards, R.S., Chow, C.W.K., Doi, S.A.R., Schirra, H.J., Buck, M., Samaratunga, H., ... Gardiner, R.A. (2016). Prostate-based biofluids for the detection of prostate cancer: A comparative study of the diagnostic performance of cell-sourced RNA biomarkers. Prostate International, 4(3), 97-102.
https://doi.org/10.1016/j.prnil.2016.04.002