Kinetic fluorescence RT-PCR is highly sensitive for detection of germ-cell-tumor-specific transcripts in peripheral blood.
The aim of our study was to determine whether conventional staging in patients with testicular germ-cell-tumors (GCT) could be supplemented by quantification of beta-human choriogonadotropin mRNA levels in peripheral blood using kinetic fluorescence RT-PCR. Blood samples from 41 patients with GCT of different clinical stages (CS) were pre-therapeutically examined by kinetic fluorescence RT-PCR with the LightCycler for beta-human chorionic gonadotropin (beta-HCG) mRNA expression levels. The controls comprised of samples taken from patients 3 months after treatment, from patients with inflammatory testicular diseases or non-germ-cell-tumors and from healthy males (n=66). Six positive results [cut-off level: normalized beta-HCG mRNA (Nbeta-HCG) >400 relative gene expression (RGE)] were found in controls (specificity 90.9%, 95% CI: 76.9-97.3%). The overall ratio of positive PCR results in the group of GCT patients was 82.92% (34/41) (CS I 18/23, CS IIa-b 6/7, CS >IIb 10/11) (sensitivity 82.9%, 95% CI: 65.1-91.2%). The average Nbeta-HCG level in patients with clinical stage I tumors was 63772.0+/-125720.5 (mean +/- standard deviation) relative gene expression (RGE), 35076.0+/-52253.5 RGE in those with CS IIa-b tumors and 87298.3+/-120895.3 RGE in those with CS >IIb tumors. Kinetic fluorescence RT-PCR for tumor-specific gene products is, in contrast to qualitative RT-PCR, a promising approach to improve conventional staging in clinical low-stage testicular germ-cell-tumors. With high specificity, its sensitivity is higher than that of the corresponding serum tumor marker (82.92% vs 48.72%).
Schrader
M
M
Department of Urology, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, D-12200 Berlin, Germany. mark.schrader@charite.de
Krause
H
H
Weikert
S
S
Straub
B
B
Schostak
M
M
Christoph
F
F
Miller
K
K
D014408:Biomarkers, Tumor / Q000235:genetics; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D052138:Genes, Neoplasm / Q000235:genetics*; D006801:Humans; D007700:Kinetics; D007962:Leukocytes / Q000378:metabolism; D008297:Male; D009367:Neoplasm Staging; D009373:Neoplasms, Germ Cell and Embryonal / Q000235:genetics* / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012334:RNA, Neoplasm / Q000097:blood* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence; D014158:Transcription, Genetic / Q000235:genetics*
D014408:Biomarkers, Tumor; D018997:Chorionic Gonadotropin, beta Subunit, Human; D012333:RNA, Messenger; D012334:RNA, Neoplasm