Improved Detection of Cervical Cancer and High Grade Neoplastic Lesions by a Combination of Conventional Cytology and DNA Automated Image Cytometer

OBJECTIVE: To reduce false-negative rates of population based cervical screening programs employing conventional cytology in combination with automated DNA image cytometer. METHODS: Involved cervical samples from a total of 3603 women were taken by a cervix brush and then placed into a fixative solution. The cells were separated from mucus by mechanical and chemical treatment after which they were deposited onto microscope slides by a cytospin. Two slides were prepared from each case; one slide was stained by Papanicolaou stain for conventional cytology examination, while the other slide was stained by a DNA specific and stoichiometric stain. The latter slide was used to determine the relative amount of DNA in the cell nuclei in order to assess the ploidy status of the epithelial cells. Enrolled in the study, 157 women were followed by colposcopy examination where punch biopsies were taken from the visible lesions or from suspicious areas. The results of the conventional cytology were then compared to the DNA image cytometer for all samples. RESULTS: Histopathology diagnosed 51 lesions from the 132 biopsied cases as CIN2 or higher, including 27 CIN2, 16 CIN3 and 8 invasive cancers. Conventional cytology correctly identified 29 of the 51 high grade CIN and invasive cancer, while DNA image cytometer correctly identified 38 high grade CIN and invasive cancer using the criterion that at least three cells were found on the slide that contained DNA amount in excess of 5c. 42 out of 51 high grade CIN and invasive cancer were found by conventional cytology in combination with DNA image cytometer. Sensitivities were 56.8%, 74.5% and 82.4%, while specificities were 86.2%, 81.5% and 81.5% in conventional cytology, DNA image cytometer and combination both cytology and DNA image cytometer respectively. CONCLUSION: The study demonstrated that screening for high grade neoplastic lesions and cervical cancer by DNA image cytometer or combination of conventional cytology and DNA image cytometer is more sensitive than conventional screening approach.