The Clinical Application Of HTERC Gene In Paraffin-embedded Tissues Of Cervical Lesions Detected By FISH

Objective1. To detect the genomic amplification of human telomerase gene (hTERC) in paraffin-embedded tissues of cervical intraepithelial neoplasia (CIN) and cervical cancer(CC) by fluorescence in situ hybridization (FISH).2. To investigate the clinical application of hTERC gene in cervical cancer screening and diagnosis or treatment of cervical cancer and precancer lesions by comparing the results of hTERC gene in paraffin-embedded tissues with cervical cytology, HPV-DNA testing, colposcopy and biopsy pathology.Methods1. To collect 148 cases of cervical paraffin-embedded tissues of biopsy or surgical resection as the study groups in the Department of Gynecology and Obstetrics of the First Affiliated Hospital of Jinan University, between October 2008 and February 2011. Five research groups were divided based on the histology biopsy, including CINⅠ(30 cases),CINⅠ-Ⅱ(28 cases),CINⅡ(35 cases),CINⅢ(35 cases) and cervical cancer (20 cases),of which 15 cases of initial treatment were the stageⅠa～Ⅱa according to the FIGO (2000) (11 cases of squamous cell carcinoma,3 cases adenosquamous carcinoma, and 1 case adenocarcinoma),5 cases recurred after treatment. To detect the genomic amplification of hTERC gene in the paraffin-embedded tissues of each group above by FISH. Selecting 18 cases normal, chronic cervicitis or metaplasia of squamous epithelium as the control group at the same time, and establish the threshold.2. All subjects received thinprep cytologic test(TCT), genital human papillomavirus (HPV) detected by improved HybriMax, colposcopy and biopsy before treatment. The patients of the pathological classification of cervical lesions>CINⅠ-Ⅱwas treated by loop electrosurgical excision procedure (LEEP) or cold-knife conization (CKC), hysterectomy when necessary. To compare the relationship between amplification of hTERC gene and cervical cytology, HPV-DNA detection, colposcopy, and the changes of pathological grade preoperatively and postoperatively. 3. To calculate and compare with the sensitivity, specificity, accuracy, positive predictive value, negative predictive value, positive likelihood ratio, negative likelihood ratio and Youden index of the cervical cytology, HPV-DNA detection, colposcopy, and hTERC genetic testing in the paraffin-embedded specimens for predicting high-grade cervical lesions, taking pathological findings as the standard.Results1. The rate of cells satisfaction after slide pretreatmen was 98.2%(166/169) and the rate of successful hybridization was 89.2%(148/166) detecting hTERC gene in cervical paraffin-embedded tissues by FISH.2. The genomic amplification rate of hTERC in the control group, CINⅠ,CINⅠ-Ⅱ, CINⅡ, CINⅢand cervical cancer group were 5.6%,10.0%,32.1%,65.7%,88.6% and 95.0% respectively. The difference of hTERC genomic amplification between control group, CINⅠand CINⅠ-Ⅱ, CINⅡ, CINⅢ,cervical cancer was statistically significant (P<0.05).The difference between CINⅠand CINⅠ-Ⅱwas statistically significant (P<0.05), while showed no significant difference between CINⅠ-Ⅱand CINⅡ(P>0.05). The genomic amplification rate of hTERC in≥CINⅡwas higher than it in CINⅠand below(P<0.05). The genomic amplification rate of hTERC in cervical paraffin-embedded tissues increased with the degree of cervical lesion gradually worsened (γ2=12.270, P<0.05).3. The difference of hTERC genomic amplification between high-risk HPV positive and negative groups was statistically significant (P<0.05),while showed no significant difference among high-risk HPV genotypes (P>0.05). Comparing with the genomic amplification of hTERC between pathological upgrade and downgrade group in preoperative and postoperative pathological findings, the difference was statistically significant (P<0.05).4. The sensitivity, specificity, accuracy, positive predictive value, negative predictive value, positive likelihood ratio, negative likelihood ratio and Youden index of the genomic amplification of hTERC in the paraffin-embedded specimens for predicting high-grade cervical lesions were 81.1%,79.3%,80.4%,85.9%,73.0%,3.92,0.24 and 0.60 respectively. The sensitivity,accuracy and negative predictive value was significantly higher than that of cytology(P<0.007); and the specificity and positive predictive value was significantly higher than that of HPV testing, the difference was statistically significant (P<0.007).Conclusion1. The genomic amplification of hTERC in paraffin-embedded tissues by FISH had the advantages of obtaining specimens easily, accurately, cell stability, high successful rate of slide pretreatment, satisfactary background, cells quantity, and strong fluorescence signals.2. The genomic amplification rate of hTERC in cervical paraffin-embedded tissues increased with the degree of cervical lesion gradually worsened. There was positive correlation between amplification of hTERC and high-risk HPV infection, but showed no significant association among HPV genotypes. The detection of hTERC gene had high sensitivity and specificity for predicting high-grade cervical lesions.3. Detection the genomic amplification of hTERC in cervical lesions by FISH can be used as following:①to make up the deficiency of cytology and HPV testing in cervical lesions screening.②to help pathology to differentiate the diagnosis of cervical lesions, reducing the missed diagnosis of high-grade cervical lesions by point biopsy.③to detect effectively CINⅡor higher lesions assisting the"three steps" technique in cervical cancer screening.④to predict the risk factors of cervical tumor progression and residual lesions or recurrence after treatment of cervical lesions.