O‐8 Detection of human telomerase gene (TERC) amplification in cervical neoplasia: a retrospective study of 50 patients with normal smears or mild or moderate dyskaryosis

Recent comparative genomic hybridisation studies (Heselmeyer-Haddad et al., 2003) indicated the involvement of extra copies of 3q in invasive cervical carcinoma. In 2005, the same group demonstrated the use of a FISH probe set, involving the human telomerase gene (TERC) located at 3q26, on conventional cervical smears. Their retrospective study of 59 patients showed that gains of TERC could predict progression from lower grade smear abnormality (mild or moderate dyskaryosis) to CIN3 and invasive carcinoma. It also demonstrated that 33% of normal conventional smears from women that subsequently developed CIN3 or invasive carcinoma showed extra copies of TERC. We present the results from a larger retrospective FISH study, using the same TERC probe kit (under development by Vysis/Abbott), on a selection of 50 patients with normal smears or mild or moderate dyskaryosis that later progressed to CIN3, Using the probe set along with an adapted de-staining technique we achieved a 92% success rate compared to the previous study, achieving only 50%. The results showed that TERC gains increase with the grade of dyskaryosis (60% for mild dyskaryosis and 82.4% for moderate dyskaryosis). This concurs with previous studies which have proposed that the acquisition of TERC is an important genetic event in the progression of cervical dysplasia to cervical cancer. For the cohort of patients classified as cytologically normal that subsequently developed CIN3, 28.5% were positive for TERC gain, demonstrating the potential use of TERC detection by FISH as an early prognostic indicator of disease progression.