Primary screening with liquid-based cytology in an unscreened population in rural China, with an emphasis on reprocessing unsatisfactory samples

OBJECTIVE: To determine the sensitivity and specificity of liquid-based cytology in a high-risk, unscreened population. STUDY DESIGN: A crosssectional comparative trial of multiple screening techniques. This report focuses on the performance of liquid-based cytology using biopsy as the standard. RESULTS: In total, 1,997 women were screened. All subjects had a minimum of five cervical biopsies. Of the subjects, 4.3% had CIN 2 on biopsy, The ThinPrep Pap with ASCUS as positive had a sensitivity for CIN 2 of 94% and specificity of 78%; the sensitivity for CIN 3 was 98% and for cancer, 100%. The unsatisfactory rate due to bloody specimens was 7.9% (158/1,997). After reprocessing, the unsatisfactory rate was 0.15% (3/1,997). CONCLUSION: Reprocessing effectively recovers ThinPrep samples otherwise unsatisfactory due to blood and mucus. The ThinPrep Pap test is a highly sensitive screening test when used in a high-risk, unscreened population.