Comparison of Liquid Based Cytology (LBC), Conventional Pap Smear and Human Papilloma Virus Detection (When indicated) to Detect Cervical Premalignant and Malignant lesions

Background: There is a strong causal association between human papillomavirus (HPV) and cervical cancer. Currently HPV DNA test is recommended as a triage for minor Cytological abnormalities and follow up of highgrade lesions. Aims: To examine the efficacy of Conventional Pap smear (CPS), Liquid based cytology (LBC) and HPV (Human papilloma virus) DNA test as independent screening tests to detect squamous intraepithelial lesions (SIL) of the uterine cervix. To study the efficacy of dual screening tests by using the following combinations: a) CPS and LBC, b) CPS and HPV DNA test, c) LBC and HPV DNA test with colposcopy as the gold standard. Material and Methods: This is a cross sectional screening study inclusive of 1064 women. Either CPS smears alone or both CPS and LBC were prepared. HPV DNA testing was done for cases reported as atypical squamous cells of undetermined significance (ASC-US) or more on cytology. Statistics-Cohen's Kappa coefficient is a statistical measure of agreement of the screening test with the gold standard. Results: We found maximum Sensitivity (Sn) with LBC (89.66%) as a stand-alone test. While in dual screening testing, maximum Sn was obtained by combining CPS with LBC. Maximum Specificity (Sp) was obtained with HPV DNA test (97.89%) when done independently and it was of high diagnostic value (Sp=100%) when done in combination with either CPS or LBC. Conclusion: The combination of HPV DNAtest with either CP or LBC had best agreement with the Colposcopy when done as a triage for borderline cytological abnormalities.