Role of liquid based cytology in detection of human papilloma virus and diagnosing oral premalignant and malignant lesions.

Liquid based cytology (LBC) is relatively a newer method of exfoliative cytology for diagnosing cervical cancers and detection of Human Papilloma Virus (HPV). Its use in diagnosing oral squamous cell carcinoma (OSCC) is less explored. We aim to compare LBC with conventional cytology in diagnosing oral premalignant and malignant lesions and study the role of LBC in detecting HPV. A cross-sectional observational study done at a tertiary hospital on patients above 18 years clinically suspicious of oral malignant and premalignant lesions. Samples were taken using cytobrush. Conventional and LBC smears were compared using specific cytomorphologic criteria. HPV testing was done using Polymerase Chain Reaction (PCR). Statistical analysis: Data collected was entered in Microsoft Excel and analyzed using MedCalc software Version18.2.1. Numbers and percentages represented the qualitative data and mean and standard deviation represented quantitative data. Wilcoxon Signed Rank test was applied. The accuracy of cytological screening test was presented using sensitivity, specificity and receiver operating characteristic (ROC) curve. Background, uniform distribution, cellular overlapping and morphology was statistically significant with p value< 0.05. ROC and Youden index showed the sensitivity of conventional method was 56.25% and specificity was 100% where as in case of LBC, sensitivity was 62.5% and specificity was 75%. LBC does not significantly outperform conventional smear preparation for routine diagnostic and mass screening procedures. Negative result of HPV DNA in all cases using LBC vials questions the utility of cytology for HPV detection and etiological role of HPV in OSCC. [ABSTRACT FROM AUTHOR]