Combined nested RT-PCR assay for prostate-specific antigen and prostate-specific membrane antigen in prostate cancer patients : Correlation with pathological stage

• Published in: Cancer research (Chicago, Ill.) Vol. 58; no. 7; pp. 1456 - 1459
• Main Authors: GRASSO, Y. Z, GUPTA, M. K, LEVIN, H. S, ZIPPE, C. D, KLEIN, E. A
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA American Association for Cancer Research 01.04.1998
• Subjects: Adenocarcinoma - blood; Adenocarcinoma - pathology; Antigens, Surface; Biological and medical sciences; Carboxypeptidases - blood; Female; Glutamate Carboxypeptidase II; Humans; Male; Medical sciences; Neoplasm Staging; Nephrology. Urinary tract diseases; Polymerase Chain Reaction - methods; Prostate-Specific Antigen - blood; Prostatic Neoplasms - blood; Prostatic Neoplasms - pathology; Transcription, Genetic; Tumors of the urinary system; Urinary tract. Prostate gland; Adenocarcinoma; Human; Biological fluid; Urinary system disease; Prostate disease; Tumor associated antigen; Reverse transcription; Malignant tumor; In vitro; Blood; Prostate specific antigen; Polymerase chain reaction; Clinical stage; Mononuclear cell; Tumor progression; Male genital diseases; Prostate
• ISSN: 0008-5472; 1538-7445

Nested reverse transcription (RT)-PCR for prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSM) can detect circulating prostatic cells in patients with prostate cancer. We evaluated the role of a combined screening approach for PSA and PSM in prostate cancer staging. We examined the peripheral blood samples from 136 patients with adenocarcinoma of the prostate (PCA), 15 patients with benign prostatic hyperplasia, 15 normal male subjects, and 5 female subjects. The controls (benign prostatic hyperplasias, normal males, and normal females) were negative for both PSA and PSM. In patients with metastatic PCA (n = 11), 100% were positive by combined PSA/PSM (64% by PSA and 91% by PSM). In biochemical failure PCA patients (n = 18), 39% were positive by PSM, compared to only 6% by PSA. In patients with clinically localized PCA (n = 107), 48% were positive by combined PSA/PSM approach (43% by PSM and 14% by PSA). These results show that PSM is a more sensitive marker than PSA in detecting circulating prostatic cells (P < 0.0001). We correlated preoperative RT-PCR results with final pathological stages in 67 prostatectomy patients. RT-PCR positivity was 81.5% in patients with non-organ-confined disease versus 37.5% in organ-confined disease (P = 0.001). PSA/PSM RT-PCR had an odds ratio of 7.3 (95% confidence interval, 2.3-23.4; P = 0.001) in predicting tumor extracapsular extension. PSA/PSM RT-PCR was a better predictor of tumor extracapsular extension than initial serum PSA, clinical stage, and biopsy Gleason score. Our data show that PSA/PSM nested RT-PCR may provide the staging information unavailable from the current modalities. The ultimate impact of this technique in the management of patients with prostate cancer will require continued investigation.