Objective: This study sought to ascertain the significance of augmented high-grade squamous intraepithelial lesion (HSIL) detection by Pap test using both conventional smear and liquid-based cytology (LBC) in a high-risk population.
Study design: We conducted a direct-to-vial study to compare the diagnostic performance of Pap smear versus LBC in a high-risk population of women referred for colposcopy at a gynecologic ambulatory clinic at the Barretos Cancer Hospital in Brazil during 2011.
Results: The detection of both low-grade squamous intraepithelial lesions (LSILs) and HSILs was significantly greater (p = 0.04 and p = 0.033, respectively) in the LBC arm [84 LSIL cases (5.7%) and 148 HSIL cases (10.1%)] than in the conventional smear arm [66 LSIL cases (4.1%) and 126 HSIL cases (7.9%)]; however, no differences were found for invasive squamous carcinoma or adenocarcinoma (p = 0.678). Of 3,071 women who were examined cytologically (1,604 conventional preparations and 1,467 LBC) and colposcopically, biopsies were available for 279 conventional preparations (17.6%) and 325 LBC preparations (22.2%). No significant differences were found between the methods with respect to diagnostic performance.
Conclusion: LBC was significantly superior to conventional smears for the detection of LSILs and HSILs, but these results did not influence biopsy confirmation. Both methods showed similar performances with high positive predictive values but very low sensitivities.