Telomerase-A molecular marker for cervical cancer screening.

Cervical cancer is one of the most common cancers in women and can be routinely screened for by the Papanicolaou smear. Screening for HPV high-risk types 16 and 18 has augmented the sensitivity of this test, but still some cases remain undetected. We have investigated the utility of assaying telomerase activity as a possible screening marker for cervical cancer. Telomerase activity was studied in relation to HPV 16/18 infection, Papanicolaou smear cytopathology, and biopsy histopathology in a total of 88 subjects, consisting of 29 cervical cancer cases, 19 control hysterectomy samples, 16 precancerous cervical scrapes, 6 cervical samples from other gynecological malignancies, and 18 normal healthy cervical scrapings. Telomerase activity was detected in 96.5% of cervical tumor samples and in 68.7% of premalignant cervical scrapings but was not detected in control hysterectomy samples and in cervical scrapings of normal healthy controls. Telomerase assay had a diagnostic accuracy of 95.8 in tissue samples, 79.1 in scrapings and 91.2 in all. Whereas HPV-16/18 subtyping had a diagnostic accuracy of 89.5% in tissue samples, 70.5% in scrapings, and 82.1% in all. There was also 71% agreement between telomerase activity and HPV-16/18 infection. The absence of telomerase activity in cervical scrapes from healthy women indicated the potential of telomerase to serve as a good screening marker for the early diagnosis of cervical cancer. For the first time we have also shown the ability of telomerase to detect micro and probably occult metastasis in gynecological malignancies.