Background and objectives: Cervical cancer is the most common cancer in Indian women and is a leading cause of death in women worldwide. Cervical cancer develops from pre-neoplastic cervical intraepithelial neoplasia (CIN). This study was conducted to evaluate telomerase activity as a tumor marker for the detection of cancer in patients with CIN and cervical cancer. The results were compared with human papillomavirus (HPV) status, clinical staging, and histopathologic studies.
Methods: Telomerase activity was detected using the PCR-based telomeric repeat amplification protocol (TRAP) assay in cervical tissues collected by routine punch biopsy from the uterine cervix of patients with suspected cervical cancer. High-risk (HR) HPV-16 and -18 status was determined in all the study groups, including controls. A total of 125 patients (including 50 patients with CIN and 75 patients with cervical cancer [including nine patients with adeno-squamous disease]) and 22 control subjects were studied. The sensitivity and specificity for detecting CIN and cervical cancer were calculated.
Results: Patients with grade I, II, and III CIN showed 17%, 33%, and 57% positivity for telomerase, respectively. In patients with cervical cancer, those at early clinical stages (Ia-IIb) showed 68% positivity and those at later clinical stages showed 92% positivity for telomerase activity. In the present study, telomerase positivity correlated significantly with the detection of HR HPV-16 and -18 (p < 0.001). As a diagnostic test, none of the described analyses combined a sensitivity of > or =90% with a specificity of > or =90%, except in patients with advanced cancer when telomerase activity was used as a diagnostic test.
Conclusion: Our findings suggest that telomerase activation is a relatively early event in cervical carcinogenesis and correlates with the grade of cervical lesion, HR-HPV status (16 and 18 subtypes), and clinical staging. Hence, these associations suggest it as a possible target for detection of cervical cancer.