Highly specific detection of prostate‐specific antigen‐positive cells in the blood of patients with prostate cancer or benign prostatic hyperplasia, using a real‐time reverse‐transcription‐polymerase chain reaction method with improved sensitivity

• Published in: BJU international Vol. 102; no. 11; pp. 1566 - 1572
• Main Authors: Barbero, Giovanna, Destefanis, Paolo, Procida, Simone, Mandili, Giorgia, Ulliers, Daniela, Ceruti, Carlo, Fiori, Cristian, Maule, Milena M., Fontana, Dario, Giribaldi, Giuliana, Turrini, Franco
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.12.2008; Wiley-Blackwell
• Subjects: Biological and medical sciences; BPH; circulating cells; Feasibility Studies; Gynecology. Andrology. Obstetrics; Humans; Male; Male genital diseases; Medical sciences; Neoplastic Cells, Circulating - chemistry; Neoplastic Cells, Circulating - pathology; Nephrology. Urinary tract diseases; prostate cancer; Prostate-Specific Antigen - blood; prostate‐specific antigen; Prostatic Hyperplasia - diagnosis; Prostatic Neoplasms - diagnosis; quantitative RT‐PCR; Reverse Transcriptase Polymerase Chain Reaction - standards; Sensitivity and Specificity; Tumors; Tumors of the urinary system; Urinary tract. Prostate gland; Nephrology; RNA-directed DNA polymerase; Prostate disease; Tumoral marker; Urology; Prostate specific antigen; Benign prostatic hyperplasia; Benign neoplasm; Diagnosis; Male genital diseases; Reverse transcription polymerase chain reaction; Quantitative analysis; Human; Urinary system disease; Enzyme; Transferases; circulating cells; Malignant tumor; Method; Real time; Nucleotidyltransferases; Blood cell; Sensitivity; BPH; quantitative RT- PCR; Molecular biology; Prostate cancer; Cancer; prostate-specific antigen
• ISSN: 1464-4096; 1464-410X
• DOI: 10.1111/j.1464-410X.2008.07797.x

OBJECTIVE To assess the presence of circulating prostate‐specific antigen (PSA)‐expressing cells in patients with prostate cancer or benign prostatic hyperplasia (BPH), and to determine their diagnostic usefulness using a highly sensitive quantitative real‐time reverse‐transcription polymerase chain reaction (qRT‐PCR) method. PATIENTS, SUBJECTS AND METHODS Venous blood samples were obtained from 175 patients with prostate cancer (12 metastatic and 163 not metastatic), 49 with BPH, and 50 healthy volunteers. To improve the specificity and sensitivity of the qRT‐PCR three innovative features were combined; a primer overlapping two adjacent exons to inhibit nonspecific amplification; a no‐end‐point first round amplification to increase the sensitivity; and a target‐specific primer for the RT phase to increase the specificity. RESULTS The sensitivity of the method was 1 cell/mL of blood and the interassay coefficient of variation was 10.5%. None of the healthy subjects tested positively, while 9% of those with prostatic cancer and 14% with BPH had PSA‐positive cells in the blood. There was a positive association between a positive test and the National Comprehensive Cancer Network classification in the patients with newly diagnosed prostate cancer (P = 0.022). There were no additional statistically significant associations. CONCLUSION Our results strongly indicate that although there were no false‐positive results and the sensitivity of the method was increased to maximal levels, a low frequency of positive results in patients with prostatic cancer and a high frequency of positive results in those with BPH seems to discourage the use of PSA‐positive circulating cells in the search for a clinical diagnosis of prostate cancer.