Liquid based cytology improves the positive predictive value of glandular smears compared to conventional cytology

Purpose: To investigate whether the introduction of liquid-based cytology (LBC) in an urban setting decreases the diagnosis of glandular neoplasia (grade 6) and improves the positive predictive value (PPV) of cervical cytological screening. Methods: A retrospective database review was conducted identifying women with cervical cytological abnormalities including glandular neoplasia (grade 6) before and after the introduction of LBC. Results: Following the introduction of LBC the rate of glandular neoplasia (grade 6) referrals fell from 1.08% to 0.69% of all cervical cytological abnormalities. There was a significant reduction in 'abnormal' cytological samples subsequently found to be associated with no invasive or preinvasive disease but no decrease in the number showing preinvasive or invasive disease. A significant decrease in number of patients having a final diagnosis of normal/inflammatory or wart changes was seen in those patients referred during the LBC period (p <0.01). Conclusion: The introduction of LBC in an urban setting decreased cytological glandular neoplasia referrals but not at the expense of missing preinvasive and invasive cancers. It has also increased the PPV of cervical sampling to detect preinvasive and invasive cancer from 59.6% to 76.0%.