COMPARISON OF CONVENTIONAL PAP SMEAR AND LIQUID BASED CYTOLOGY FOR CERVICAL CANCER SCREENING AND ITS CORRELATION WITH BIOPSY

Dr. Saranya.B; Dr. C.Mythily

Volume : X, Issue : V, May - 2020

COMPARISON OF CONVENTIONAL PAP SMEAR AND LIQUID BASED CYTOLOGY FOR CERVICAL CANCER SCREENING AND ITS CORRELATION WITH BIOPSY

Dr. Saranya. B, Dr. C. Mythily

Abstract :

Introduction: Cervical carcinoma is the fourth most common malignancy worldwide and fourth most common cause of deaths due to cancer worldwide which makes it an important public health problem. The cellular changes in cervix and intraepithelial lesions can be detected many years before the patients present with frank invasive carcinoma. So, cervical screening programs were introduced worldwide. For many years, Conventional PAP smears were used for screening. Though it led to drastic reduction in number of cervical carcinoma cases, it had high false negativity. So, newer methods like Liquid based cytology were introduced. This study was undertaken to compare Liquid based cytology with Conventional PAP smear and to correlate the results with biopsy obtained from the same patient. Materials and methods: This study was done on randomly selected 100 patients attending the Pilot screening project at Department of Obstetrics and Gynaecology, Thanjavur medical college , Thanjavur and their personal details like age , puberty age , number of children and their presenting complaints were obtained. The sample for Conventional PAP smear was taken using Ayre’s spatula and slides were prepared. Sample for Liquid based Cytology was taken using the Cytoush and the sample was rinsed in the fixative provided by the manufacturer. The sample was then centrifuged and slides were prepared. Both the slides were then stained using the Rapid PAP stain. Colposcopy was done and biopsy was taken from the suspicious area which was then processed and stained by Haematoxylin and Eosin. The slides were analysed and the following results were obtained. Results: Most of the patients who attended the screening program were in the fourth decade of life. Most of the cases with dysplasia (26%) were in the age group of 21 – 40 years. Most of the cases were in the Socio economic Class II of the Modified Prasad’s classification. Dysplasia was found more in the Socio economic class III (12% of cases). 90% of cases started sexual activity before 25 years of age and out of these 90 patients, 92.3% had dysplasia. Dysplasia was more in patients with parity 3 (14% of cases). 46% of cases presented with white discharge per vaginum. Cytological abnormality was found in 28 cases (28%) by LBC, whereas conventional Pap smear detected abnormality in only 22 cases (22%). 96 cases (96 %) were satisfactory for evaluation in LBC and 92 cases (92%) in conventional Pap smear. ASC was found in 12% of cases in Conventional PAP whereas it was detected in only 6% of cases in LBC. LSIL and HSIL were found in 8% and 2% of cases in conventional PAP smear whereas it was found in 12% and 8% of cases in LBC. No carcinoma was found in Conventional PAP smear whereas 2% of cases had carcinoma features in LBC. Sensitivity and specificity of PAP smear in detecting LSIL was 40% and 93% whereas for HSIL it is 50% and 100%. Sensitivity and specificity of LBC in detecting LSIL is 66% and 94% whereas for HSIL it was 100% and 96%. Overall sensitivity and specificity for Conventional PAP smear is 55.5% and 83.7% whereas for LBC it is 83% and 86.5% respectively. Statistically, LBC and histopathology was highly correlated (r = 0.617) whereas only medium level of correlation was found for Conventional PAP smear (r = 0.4651) Conclusion: Liquid based cytology is strongly advocated in the best interest of public health especially in countries like India where more number of people are in the lower socioeconomic status category, it improves the sample quality and reduces the likelihood of false negative results and hence improving the efficacy of the screening programs and thereby reducing the incidence of cervical cancer.