Objective: To investigate the genomic amplification of the human telomerase RNA component (hTERC) gene in cervical cytology and evaluate its role in screening of cervical lesions.
Methods: A total of 301 cases were recruited, with liquid-based cytology diagnoses as normal (n = 203), atypical squamous cells (ASC, n = 66), low-grade squamous intraepithelial lesions (LSIL, n = 18), and high-grade squamous intraepithelial lesions (HSIL, n = 14). Following cytological examination, the slides were analyzed using a two-color fluorescence in situ hybridization (FISH) probe targeted to chromosome 3q26 containing hTERC. The hTERC findings were compared to the cytologic and histologic results, as well as high-risk human papilloma viruses (HPV) results.
Results: Genomic amplification of hTERC was found in 3.0% (6/203) of normal specimens, 21.2% (14/66) of ASC, 44.4% (8/18) of LSIL and 92.9% (13/14) of HSIL, with a significant difference in each pair wise (all P < 0.05). Significantly more cells with 3q26 gain were found in cervical intraepithelial lesion (CIN)II than in CINI (75.0% vs. 20.0%), as well as in CINIII (86.7% vs. 20.0%) and squamous cervical cancer (SCC) than in CINI (100.0% vs. 20.0%)(all P < 0.01). The sensitivity of hTERC amplification was significantly higher than cytological screening (82.6% vs. 17.4%, P < 0.01), and its specificity was higher than high-risk HPV test (67.8% - 73.5% vs. 25.6% - 27.7%, P < 0.01) in the diagnosis of HSIL (CINII - III). The abnormal hTERC signal type mostly was 2:3 in CINI (84.9%); whereas in CINII - III, 2:3, 2:4 and 4:4 accounted for 44.6%, 24.8% and 17.8%, respectively.
Conclusion: Testing the gain of chromosome 3q26 in cytological specimens using specific probe for hTERC is powerful in screening of HSIL, and the amplification patterns of 2:4 and 4:4 may serve as potential prognosis markers.