Evaluation of Pap smear, high risk HPV DNA testing in detection of cervical neoplasia with colposcopy guided or conventional biopsy as gold standard

Introduction: The present work was planned to compare the results of different diagnostic procedures cervical Pap smear, HPV DNA testing, colposcopy directed biopsy or conventional cervical biopsy and evaluating their correlation for final diagnosis of cervical neoplasia. Methodology: A prospective observational study was carried out on 100 patients attending the Gynaecology OPD of Calcutta National Medical College & Hospital, Kolkata, from July 2009 to June 2010. Pap smear and high-risk HPV DNA testing was done on selected patients. Some were subjected to colposcopy and guided biopsy if needed. The rest of the patients underwent conventional biopsy. Results: We found sensitivity of Pap smear was 75.0 % (95% CI =45.8-93.2%), specificity95.45% (95% CI=89.4-98.5%) , PPV69.23% (95% CI=41.3-89.4%) and NPV96.55% (95% CI=90.9-99.1%). Sensitivity of HPV DNA was 83.33%, (95% CI=54.9-97.1%), specificity97.73% (95% CI=92.7-99.6%), PPV-83.33% (95% CI=54.9-97.1%), NPV97.72% (95%CI=92.7-99.6%). Sensitivity of combined test (Pap smear + HPV DNA test) was 75% (95%CI=45.9-93.2%), specificity100%, PPV100% and NPV 96.7% (95%CI=91.3-99.1%). Conclusion: Addition of HPV DNA testing with cytology can improve the detection rate of cervical intra epithelial lesions with a high specificity and high NPV. Kewords: cervical neoplasia, Pap smear, colposcopy