Pap test accuracy and severity of squamous intraepithelial lesion.

Abstract

Cytology smears and guided biopsies are the most widely used diagnostic standards for cervical cancer (CC) screening in the developing countries. To evaluate the performance of conventional cytology in estimating the presence and grade of cervical disease against the reference standard of histopathology. After primary screening for CC, directed biopsies were performed and compared with histopathology results. Papanicolaou (Pap) smears and biopsies from 3194 women in the age group of 14-98 years were included. Cytology results were provided by doctors who performed the cervical biopsies. The accuracy of Pap smear was measured by sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) calculated using the statistical analysis program PSPP 0.7.8. The sensitivity of conventional cytology (Pap smear) for women with low-grade cervical intraepithelial neoplasia or less serious lesions (CIN1-) was 93% and specificity was 73%. The sensitivity and specificity of cytology for women with high-grade cervical intraepithelial neoplasia or cancer (CIN2+) was 64% and 84%, respectively. Cytology is a sufficiently sensitive test for detection of cervical lesions and can be used as a primary testing tool to triage.