Rapid, quantitative reverse transcriptase-polymerase chain reaction: application to intraoperative molecular detection of occult metastases in esophageal cancer.
OBJECTIVE
Our earlier data showed that quantitative reverse transcriptase-polymerase chain reaction can discriminate patients with node-negative cancer who are at high risk for recurrence. The objective of this study was to determine whether a new, more rapid quantitative reverse transcriptase-polymerase chain reaction assay could provide this information in a time frame suitable for intraoperative decision making.


METHODS
We studied formalin-fixed, archived lymph nodes from 30 patients with histologically determined node-negative esophageal cancer with rapid quantitative reverse transcriptase-polymerase chain reaction to measure expression of carcinoembryonic antigen messenger RNA. We also performed rapid quantitative reverse transcriptase-polymerase chain reaction on 37 snap-frozen lymph nodes from 23 patients. Eleven of the 23 patients had benign esophageal disorders (negative control group). The other 12 had esophageal cancer, 6 with histologically determined positive lymph nodes and 6 with histologically determined negative lymph nodes.


RESULTS
In the retrospective analysis of archival tissue from 30 patients with esophageal cancer with histologically determined negative lymph nodes, rapid quantitative reverse transcriptase-polymerase chain reaction predicted disease recurrence with a sensitivity and a specificity of 90% and 80%, respectively, and was comparable to conventional quantitative reverse transcriptase-polymerase chain reaction. In the frozen-tissue analysis rapid quantitative reverse transcriptase-polymerase chain reaction detected significantly higher levels of carcinoembryonic antigen expression in all 12 of the histologically determined positive lymph nodes than in the benign nodes. For 2 of these 12 nodes the intraoperative frozen-section analysis had negative histologic results, and N1 status was determined only on final pathologic examination. Rapid (intraoperative) quantitative reverse transcriptase-polymerase chain reaction discriminated both nodes as positive. Among the 14 histologically determined negative nodes, 1 of 3 nodes from 1 patient showed increased carcinoembryonic antigen according to rapid quantitative reverse transcriptase-polymerase chain reaction, and this patient had a clinical recurrence.


CONCLUSIONS
In our study we were able to rapidly discriminate patients with node negative-esophageal cancer who had a high risk of recurrence. In frozen tissues rapid quantitative reverse transcriptase-polymerase chain reaction correlated with final pathologic report for 11 of 12 patients. In the 1 discordant case, the quantitative reverse transcriptase-polymerase chain reaction result was positive and may have detected microscopically occult metastasis, because this patient did have disease recurrence. Rapid quantitative reverse transcriptase-polymerase chain reaction was more sensitive than intraoperative frozen sections for detecting metastatic disease. These data suggest that rapid quantitative reverse transcriptase-polymerase chain reaction may have a prognostic role and could guide intraoperative decisions.
Raja
Siva
S
Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA.
Luketich
James D
JD
Kelly
Lori A
LA
Gooding
William E
WE
Finkelstein
Sydney D
SD
Godfrey
Tony E
TE
D000368:Aged; D002272:Carcinoembryonic Antigen / Q000235:genetics / Q000378:metabolism*; D004938:Esophageal Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D005260:Female; D005629:Frozen Sections; D006801:Humans; D007150:Immunohistochemistry; D007432:Intraoperative Period; D008198:Lymph Nodes / Q000378:metabolism*; D008297:Male; D008660:Metabolism; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis*; D012333:RNA, Messenger / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity
D002272:Carcinoembryonic Antigen; D012333:RNA, Messenger