Conventional Pap smear and liquid based cytology for cervical cancer screening - a comparative study

The study was undertaken to evaluate liquid based cytology (Pap spin) and to compare the sensitivity of Pap spin with conventional Pap smear. Pap smears were taken from 160 patients with gynaecologic complaints with Ayre's spatula and endocervical cytobrush and slides prepared. The residual material on both the spatula and cytobrush were rinsed in Pap spin collection fluid and centrifuged. Direct smears were prepared from the cell button, fixed and stained by Papanicolaou stain. Colposcopy was performed in patients with abnormal smears and biopsy was performed in suspected malignant or dysplastic cases. LSIL and HSIL was diagnosed in 27 (64.4%) cases, mostly between 21-40 years, Commonest presenting complaint was discharge per vaginum seen in 68 (42.5%) cases. Cytological abnormality was found in 42 cases (26.2%) by Pap spin method, whereas conventional Pap smear detected abnormality in only 24 cases (15%). 133 cases (83.1%) were satisfactory for evaluation on Pap spin and 51 cases (31.9%) on conventional Pap smear. The commonest atypical finding on colposcopy was acetowhite area in 14 cases (31.1%). Sensitivity of Pap spin and conventional Pap smear was 97.6% and 53.7% respectively and specificity was 50% in each. Pap spin is strongly advocated in the best interest of public health as it improves the sample quality and reduces the likelihood of false negative results.