Comparative study of liquid based cytology (lbc) and colposcopy for detection of premalignant lesions of cervix

Background: To compare and analyze Liquid Based Cytology (LBC) with colposcopy in detection of premalignant lesions of cervix.
Material and methods: A randomized, observational, prospective cohort study was conducted in the Department of Obstetrics and Gynecology, Government Medical College, Patiala. 324 females were screened, 18 withdrew their consent and 6 dropped out as they fail to turn up during the later stages of study. Finally, N=300 patients were enrolled who fulfilled both inclusion and exclusion criteria. All patients were aged more than 18 years and complained of discharge per vaginum, post-coital bleeding, post-menopausal bleeding, intermenstrual or abnormal bleeding per vaginum. These patients were subjected to LBC and Colposcopy screening. However, on detection of any premalignant lesions of cervix, cervical biopsy was taken for confirmation by histopathology.
Results: Out of 73 cases detected positive by LBC, 29 cases were true positive (TP) while 44 cases were false positive (FP). 54 cases were true negative (TN) and 18 cases were false negative (FN) with accuracy of 57.24%. In colposcopy, 38 cases were TP, 3 cases were FP, 95 cases were TN and 9 cases were FN making the colposcopy 91.72 % accurate. The relationship of sensitivity results between LBC and colposcopy was p value of 0.000 whereas between LBC and Histopathological examination (HPE) was p<0.01. The relationship was comparable at p value of 0.103 between colposcopy and HPE, which was non-significant.
Conclusions: The study concluded that colposcopy to be better modality than LBC for early detection of premalignant lesions of cervix. The sensitivity, specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV) and accuracy of colposcopywas 80.85%, 96.93%, 92.68%, 91.34% and 91.72% as compared to LBC with 61.70%, 55.10%, 39.72%, 75% and 57.24% respectively.