000423: ASSESSMENT OF GENE PROMOTER HYPERMETHYLATION FOR DETECTION OF CERVICAL NEOPLASIA, A PILOT STUDY

Objective: Current cervical cancer screening is based on morphological assessment of Pap smears and associated with significant false negative and false positive results. Previously we have shown that detection of hypermethylated genes in cervical scrapings using (quantitative) methylation specific PCR (QMSP) identified ca. 60% of squamous cell cervical cancers. Aim of the present pilot-study was to evaluate whether detection of hypermethylated genes, specifically involved in both squamous cell as well as adenocarcinomas, will further improve cervical cancer screening. Patients and Methods: Cervical scrapings were obtained from 30 patients diagnosed with cervical cancer (20 squamous cell carcinomas and 10 adenocarcinomas) and 20 women with histologically normal cervices. The scraped cells were used for morphological assessment and QMSP. Hypermethylation was determined for 12 tumor suppressor genes linked to cervical carcinogenesis. To adjust for DNA input hypermethylation ratios were calculated against the housekeeping gene beta-ACTIN. Results: CALCA, DAPK, ESR1, TIMP3, APC and RAR-beta2 were significantly more often hypermethylated in cancers than in controls, while adenocarcinomas were more often hypermethylated above the highest control ratio for APC, TIMP3 and RASS- F1A. Combining four genes (CALCA, DAPK, ESR1 and APC) a sensitivity of 89% was reached (with all adenocarcinomas identified), comparable to sensitivity of cytomorphology (89%), while specificity set at 100% was superior to cytomorphology (79%) (p, 0.05). Conclusions: QMSP of four genes combined appears to have comparable sensitivity, but better specificity than ‘classic’ cytomorpho- logical assessment for identification of cervical cancer. QMSP for selected genes improves detection of squamous cell and adenocarcinoma of the cervix.