The use of real-time reverse transcription-PCR for prostate-specific antigen mRNA to discriminate between blood samples from healthy volunteers and from patients with metastatic prostate cancer.
OBJECTIVE
A clinical role for nonquantitative reverse transcription-PCR (RT-PCR) using prostate-specific antigen in blood samples from patients with prostate cancer remains undefined. Assay variation and detection of prostate-specific antigen mRNA illegitimate transcription may explain inconsistent results between studies. Defining levels of prostate-specific antigen mRNA expression in blood samples from healthy volunteers and patients with prostate cancer would allow cutoffs to be established to distinguish the two groups.


METHODS
Quantitative real-time RT-PCR for prostate-specific antigen mRNA was established and levels of prostate-specific antigen mRNA measured in bloods samples from healthy volunteers (n=21) and patients with localized (n=27) and metastatic (n=40) prostate cancer.


RESULTS
Levels of prostate-specific antigen mRNA were significantly higher in blood samples from patients with metastatic prostate cancer than in blood samples from patients with localized prostate cancer (P <0.001) or in blood samples from healthy volunteers (P <0.01); levels between patients with localized prostate cancer and healthy volunteers were no different. Assay sensitivity to detect patients with metastatic prostate cancer was 68% with specificity of 95%. In patients with newly diagnosed metastatic prostate cancer, monitoring response to hormonal therapy was possible with this assay. No correlation between levels of prostate-specific antigen mRNA and serum prostate-specific antigen protein levels was found, suggesting that prostate-specific antigen mRNA and serum prostate-specific antigen protein levels reflect different features of prostate cancer, i.e., circulating tumor cells and total tumor bulk, respectively.


CONCLUSIONS
Quantitative RT-PCR discriminates patients with metastatic prostate cancer from healthy volunteers and patients with localized prostate cancer but cannot discriminate patients with localized prostate cancer from healthy volunteers. A role for quantitative RT-PCR has been identified in the assessment and monitoring of patients with metastatic prostate cancer.
Patel
Kinnari
K
Cancer Research U.K. Clinical Centre and Department of Urology, St. James's University Hospital, Leeds, Yorkshire, United Kingdom.
Whelan
Peter J
PJ
Prescott
Stephen
S
Brownhill
Samantha C
SC
Johnston
Colin F
CF
Selby
Peter J
PJ
Burchill
Susan A
SA
D045744:Cell Line, Tumor; D018076:DNA, Complementary / Q000378:metabolism; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000166:cytology; D008297:Male; D009362:Neoplasm Metastasis; D009504:Neutrophils / Q000166:cytology; D016133:Polymerase Chain Reaction; D017430:Prostate-Specific Antigen / Q000096:biosynthesis*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000175:diagnosis*; D012333:RNA, Messenger / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D013997:Time Factors; D014158:Transcription, Genetic; D001613:beta 2-Microglobulin / Q000378:metabolism
D018076:DNA, Complementary; D012333:RNA, Messenger; D001613:beta 2-Microglobulin; D017430:Prostate-Specific Antigen