Detection of hTERT mRNA in colonic brush specimens as an adjunct to cytopathologic diagnosis of colonic adenocarcinoma.
OBJECTIVE
To investigate the role of reverse transcriptase polymerase chain reaction (RT-PCR) in determining telomerase catalytic subunit (hTERT) mRNA to assist with the diagnosis of colonic adenocarcinoma (CCA) in colonic brush cytology specimens.


METHODS
Twenty-seven colonic brushes of CCA were obtained. Initial cytologic diagnoses included CCA, suspicious for CCA (SFC), atypical (ATY) and unsatisfactory. The cytologic specimens were reviewed. A homogeneous RT-PCR assay for hTERT mRNA was performed on 27 colonic brushes of CCA and 24 controls (10 negative brushes, 6 resected CCA and 8 benign colonic mucosa from resected specimens). A RT-PCR assay for beta 2-microglobulin was used as an internal control for mRNA quality.


RESULTS
On review, the initial cytopathologic diagnosis of CCA was confirmed in all 7 cases. In addition, 7 of 19 initially interpreted as SFC and ATY seemed to demonstrate unequivocal cytomorphologic features of malignancy. Telomerase mRNA was more often expressed in CCA than in negative controls in both brush (30%) and resected specimens (57%) (P < .05). Seven cases with hTERT mRNA expression were initially diagnosed as CCA (three), SFC (three) and ATY (one).


CONCLUSIONS
CCA may be underdiagnosed in brush cytopathology. The expression of hTERT mRNA may be determined by RT-PCR in brush specimens and may eventually prove to be a useful diagnostic adjunct in the interpretation of inconclusive cases of CCA. Sparse cellularity in brush specimens may result in a relatively low rate of hTERT detection in colonic brushes of CCA; inflammatory changes may contribute to a higher-than-expected rate of hTERT expression in benign colonic epithelium.
Li
Sherry Q
SQ
Department of Pathology, Columbia University College of Physicians and Surgeons, New York, New York, USA. sli@sbhcs.com
Sheng
Zong-Mei
ZM
Baili
YuJing
Y
Erozan
Yener S
YS
O'Leary
Timothy J
TJ
D000230:Adenocarcinoma / Q000473:pathology*; D014408:Biomarkers, Tumor; D001706:Biopsy; D003110:Colonic Neoplasms / Q000473:pathology*; D004268:DNA-Binding Proteins; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019098:Telomerase / Q000235:genetics*; D001613:beta 2-Microglobulin / Q000235:genetics
D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D001613:beta 2-Microglobulin; D019098:Telomerase