Objective: The aim of the present study was to evaluate the prevalence of abnormal Pap smears as detected by liquid-based (LBP) and conventional (CPP) techniques in women who were patients in the gynecologic clinic, Thammasat University Hospital.
Material and Method: Retrospective analysis of cervical cancer screening, histopathological findings and operative procedures was done between January 2009 and December 2009. Of the 6,332 participants who underwent gynecological examination and cervical screening and had a Pap smear result as atypical squamous cells of undetermined significance or worse would be performed a further colposcopic examination.
Results: A total of 6,332 women were screened for cervical cancer in the one year period. A total of 169 abnormal Pap smears were found. Of 497 (8%) and 5,835 (92%) women were screened by LBP and CPP, respectively. The mean age of patients was 39.45 years old (14-90) and 1,550 (24.5%) women were post menopausal. The Prevalence of abnormal Pap smears was 4.0 and 2.6% in the LBP and CPP groups, respectively. Among LBP group, patients with atypical smear and LSIL (low grade squamous intraepithelial lesion) were 11 (2.29%) and 9 (1.8%), respectively. While CPP group, patient with atypical smear, LSIL, HSIL (high grade squamous intraepithelial lesion) and cancer were 73 (1.25%), 49 (0.84%), 25 (0.43%) and 2 (0.03%), respectively.
Conclusion: The prevalence of abnormal Pap smear in women who attended gynecologic clinic of Thammasat University Hospital was 4.0% and 2.6 % per LBP and CPP group, respectively. There was no significant difference in the incidence of atypical smear and false positive result between LBP and CPP.

Keywords: Abnormal Pap smears, Liquid-based, Conventional