A Comparative study and analysis of outcomes of papsmear Versus liquid based cytology with histology as reference standard in cancer cervix screening

INTRODUCTION: Cervical Cancer remains worldwide the second most common cancer among women accounting for 15% of all female cancers. It is the most common cancer among women in many developing countries constituting 20-30% of female cancers. In developed western countries it accounts for only 4 - 6% of female cancers. This difference largely reflects the impact of mass screening using cervical cytologic methods. The purpose of cytologic screening is to identify those women who have a intraepithelial lesion (CIN) and not those who have cancer. If disease can be detected & treated at this preinvasive stage outcome should significantly improve. For a screening system to be effective it must fulfill six basic requirements. a) The test must detect the disease in a stage where early treatment will provide a Superior prognosis to treatment in a later stage. b) The test must be sufficiently sensitive to detect the disease in an early stage. c) The test must be sufficiently specific to distinguish non specific changes from the disease. d) The test must be cost effective. e) The test must be sufficiently simple to administer. f) The screening procedure must be acceptable to those undergoing screening. Cervical Cytology Meets All Of These Requirements : And also in all probability cervical cancer is the only gynecological malignancy that satisfies the well recognized WHO criteria for implementation of a screening program. Existence of well defined premalignant lesions Long Latent period in which premalignant change or occult cancers can be detected and effectively treated thereby altering the natural history of the disease. A clearly defined viral etiology, which could be incorporated as a marker in mass screening program. Easy & direct access of the uterine cervix for examination and sampling. Effective treatments available for the premaligant changes. In the last 40 years developed countries like United States & British Columbia have shown a decrease in the incidence & mortality of invasive cancer cervix by effective cancer screening programmes. (Coleman et al.) But the scenario has not changed in the developing countries due to socioeconomic, cultural or political conditions. So the need to educate women & their health care providers about the importance of screening is evident. AIM OF THE STUDY: 1. To compare the cytologic diagnosis, specimen adequacy, sensitivity, cost effectiveness of Liquid based cytology with that of conventional pap test. 2. To correlate diagnostic colposcopy with histopathology in patients with abnormal cytology reports. 3. To study the accuracy of combined screening procedures. MATERIAL AND METHOD: Selection of Cases - A random selection of 300 patients attending as outpatient in gynaecological department at government Kilpauk Hospital, Chennai during the year 2005- 2006. Inclusion Criteria - Women who are sexually active, including post menopausal women. No previous screening test taken. Exclusion Criteria - Antenatal and Postnatal mothers, previous screening test taken, proven preinvasive lesions and on treatment, menstruating women. Method - A detailed history of the patient taken and the patient informed about the screening procedures and counselling given regarding the necessity for their participation in screening program. Their awareness regarding the screening Programs and tests offered were assessed. Both conventional pap and liquid based cytology were performed in the same patient. SUMMARY: Out of 300 patients screened for cancer cervix with conventional pap and Liquid based cytology in the same patient a. LBC detection rate of cervical abnormalities and HSIL was more than that of CP. b. False -ve rate of LBC only 2% c. Sensitivity 97% and false positive rate is 44% d. The sensitivity is as equal to gold standard method. e. Infection detection rate increased with LBC f. Specimen adequacy improved with LBC substantially g. The collection sample device brush found superior to wooden Ayre's spatula both not in injuring tissues and specimen collection. h. The adverse impact on a women's quality of life caused by unnecessary repeat smears and possible investigations would reduce the cost with LBC. i. The economic evidence suggests that LBC screening every 3 yrs of longer may be cost effective. j. LBC reduced the pressure on a skilled workforce. Colposcopy has become as integral part of modern gynaecologic practice. the sensitivity and specificity is high. However its main indication remains examination of women with abnormal smears and a trained personnel is required as false positive results may end up in unnecessary treatment modalities and only ecto cervix lesions can be detected. As cytology is ideal for mass screening, specimen can be obtained by non medical professional, detects lesion both in ecto and endo cervix and cost effective LBC is a better alternative and colposcopy directed biopsy can be done in patients with abnormal smears. CONCLUSION: WHO Press Release, 11 October 2001, points out that. We should aim to divert out resources for screening and treating the high risks group of women. The effort once or twice in their lifetime will reduce the incidence of cervical cancer by 50%. In this scenario mass screening with LBC which has a high detection rate for HSIL and colposcope for abnormal smears offers a potent method of rapid assessment of any dysplasia possibly present