Evaluation of colposcopy vs cytology as secondary test to triage women found positive on visual inspection test

Abstract

Colposcopic evaluation and guided biopsy is an important diagnostic step and standard of management for abnormal cytology smears in developed countries. The present study evaluates the performance of colposcopy vs conventional cytology in estimating the presence and grade of cervical disease against the reference standard of histopathology as a secondary test modality to triage women found positive on primary screening by visual inspection with 5% acetic acid (VIA). Colposcopy and directed biopsy were performed after primary screening for cervical cancer in an urban hospital cancer screening clinic between January 2000 and June 2005, in Mumbai, India. Healthy women (8863) in the age group of 35-65 years participated in the cervical cancer early detection program in the hospital and community cancer screening clinics in Mumbai. Women found positive on the primary screening test by VIA underwent diagnostic evaluation by Pap smear cytology and colposcopy evaluation with directed biopsies. Accuracy parameters and their 95% confidence intervals were calculated using 2 X 2 tables and standard formulae. The test range of sensitivity of colposcopy for the detection of histologically confirmed cervical intraepithelial neoplasia grade 1+ (CIN1+) or CIN2+ was 58.0-74.7% and that of specificity was 57.5-92.9%. The sensitivity and specificity of cytology to detect CIN2+ was 57.4% and 99.4%, respectively. Colposcopy is a good sensitive test for the detection of CIN and can be considered as a secondary testing tool to triage women found positive on VIA.