The comparison of Conventional Pap smears with Liquid Pap smears (PrepStain(TM) System) in Cervical Pap smears

Lee, Seung A; Kim, Jung Hye; Kim, Jo Eun; Park, Hyun Ju; Choi, Weon Young; Oak, Soon Ae

Abstract

OBJECTIVE
To Compare the conventional Pap smear with the Liquid Pap smear in screening of cervical cancer and to evaluate the correspondence of their biopsy results.
METHODS
From August 1, 2003 to July 31, 2005, the conventional Pap smears and the Liquid Pap smears were performed in 12,757 and 6,870 women, respectively. The results of 252 conventional Pap smear and 227 Liquid Pap smear were confirmed by colposcopic biopsy and evaluated for sensitivity, specificity, positive predictability, negative predictability and false negativity.
RESULTS
In Liquid Pap smear, there were higher proportions of ASCUS, LSIL, HSIL and CIS. And the ratio of ASCUS/LSIL were 3.32 and 3.04 in conventional Pap smear and Liquid Pap smear respectively. The conventional Pap smear showed sensitivity 71.8%, specificity 93.9%, positive predictability 82.3%, negative predictability 89.4%, and false negativity 28.2%, while the Liquid Pap smear showed higher sensitivity (72.6%), specificity (96.1%), and positive predictability (89.8%), and lower negative predictability (88.0%), and false negativity (27.4%). The positive predictability was significantly higher (95% C.I.: 1.3-13.7).
CONCLUSION
The positive predictability was significantly improved in the Liquid Pap smear. Therefore, the Liquid Pap smear is a more useful method in screening of cervical cancer.