Comparison of PAP smear and liquid based cytology as a screening method for cervical carcinoma

Objectives: To compare conventional PAP smear (CPS) and liquid-based cytology (LBC) for cervical carcinoma screening at a tertiary care hospital of South Punjab, Pakistan.

Methods: This cross-sectional study was conducted at the Department of Obstetrics and Gynecology, Nishtar Hospital, Multan, Pakistan from January 2021 to June 2021. We included a total of 265 women aged between 20 to 65 years who, presented with complaints related to cervical lesion and unhealthy cervix. The CPS and LBC methods were applied for screening of cervical carcinoma. Findings of both CPS and LBC were compared with histopathological findings to find out sensitivity, specificity, positive predictive value and negative predictive value for both techniques.

Results: In a total of 265 women, mean age was noted to be 45.4±6.8 years. White discharge per vagina was the commonest presenting complaint noted in 12 (46.8%) patients. Satisfactory smears were found in significantly more cases with LBC in comparison to CPS (p<0.001). Sensitivity CPS and LBC for the detection of low-grade squamous intraepithelial lesion (LSIL) were found to be 71.8% and 87.2% while for high-grade squamous intraepithelial lesion (HSIL), sensitivity of CPS and LBC were 61.9% and 76.2% respectively. Specificity of CPS and LBC for the detection of LSIL was found to be 97.9% and 98.7% while for HSIL, specificity of CPS and LBC was 98.7% and 99.2% respectively.

Conclusion: In comparison to conventional CPS, LBC was found to be better in terms of adequacy of smear and identification of LSIL and HSIL.