Clinical study on primary screening of oral cancer and precancerous lesions by oral cytology
Abstract Background This study was conducted to compare histological diagnostic accuracy between conventional method and liquid-based cytology (LBC) method and to clarify the effectiveness of cytology. Methods Histological diagnoses of 251 cases were classified as negative (no malignancy lesion, inflammation, and mild/moderate dysplasia) and positive [oral intraepithelial neoplasia/carcinoma in situ (OIN/CIS) and squamous cell carcinoma (SCC)]. Cytological diagnoses were classified as negative for intraepithelial lesion or malignancy (NILM), oral low-grade squamous intraepithelial lesion (OLSIL), oral high-grade squamous intraepithelial lesion (OHSIL), or SCC. Cytological diagnostic results were compared with histology results. Results Of NILM cytology cases, the most frequent case was negative [LBC n = 50 (90.9%), conventional n = 22 (95.7%)]. Among OLSIL cytodiagnoses, the most common was negative (LBC n = 34; 75.6%, conventional n = 14; 70.0%). Among OHSIL cytodiagnoses (LBC n = 51, conventional n = 23), SCC was the most frequent (LBC n = 31; 60.8%, conventional n = 7; 30.4%). Negative cases were common (LBC n = 13; 25.5%, conventional n = 14; 60.9%). Among SCC cytodiagnoses SCC was the most common (LBC n = 16; 88.9%, conventional n = 14; 87.5%). Regarding the diagnostic results of cytology, assuming HSIL and SCC as cytologically positive, the LBC method/conventional method showed a sensitivity of 79.4%/76.7%, specificity of 85.1%/69.2%, false positive rate of 14.9%/30.7%, and false negative rate of 20.6%/23.3%. Conclusions LBC method was superior to conventional method in cytodiagnosis. It was especially superior for LSIL and HSIL. Because of the false positive and false negative cytodiagnoses, it is necessary to make a comprehensive diagnosis considering the clinical findings.