Open Collections

Optimization of a Health Canada-approved image cytometry system using quantitative DNA-ploidy analysis in oral cancer screening

University of British Columbia

With <50% 5-year survival rates, oral cancer is often diagnosed at a late stage. Detection of lesions at earlier stages results in better prognosis. DNA-image cytometry (DNA-ICM) is able to detect gross alterations of cellular DNA-content representing aneuploidy, a biomarker of malignancy. Health-Canada-approved DNA-ICM system, ClearCyte (Perceptronix Medical Inc.) with a cytopathologist's review have demonstrated high sensitivity (89%) and specificity (97%) in identifying high-grade lesions. The purpose of this study was to test whether ClearCyte technology can provide a robust automated oral cancer screening method without cytopathologist’s input. A set of 218 oral brushing samples of oral cancer (n=96), severe dysplasia (n=20), reactive lesions (n=52), and normal samples (n=50) were retrieved from the bio-bank of the pan-Canadian surgical trial and community oral mucosal clinics. Cells from these liquid-based brushing samples were prepared using Cytospin4 (Thermo Scientific, Waltham, MA) and Feulgen-thionin stain reaction. Following ClearCyte scan, nuclear features were automatically calculated, and cells categorized into DNA-ploidy groups by the software: “diploid” (0.85≤DI<1.15), “hyperdiploid” (1.15≤DI<1.7), “tetraploid” (1.7≤DI<2.3), and “aneuploid” (DI≥2.3). The samples were randomized into training and test sets (70:30) based on patient’s age, sex, tobacco use and lesion site risk. The training set (77 abnormal, 72 control samples) was used to plot the receiver operating characteristic curves to determine the best predictors of pathology and identify their thresholds for optimal sensitivity. Based on the training set data, a new algorithm, iClearCyte, was created and validated using the remaining samples in the test set (n=65), where sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the iClearCyte result were calculated. Four (1.8%) out of 218 cases were excluded from the analysis due to inadequate cellular counts (<400 nuclei). The proposed iClearCyte algorithm (>1 “aneuploid” cell or ≥1.7% combined “hyperdiploid” with “tetraploid” group frequency) identified high-grade samples with the sensitivity, specificity, PPV and NPV of 100.0%, 86.7%, 89.7%, and 100.0%, respectively. In conclusion, iClearCyte test has potential to serve as robust non-invasive oral cancer screening tool, bridging geographic gap between communities and oral specialists, promoting early oral cancer detection, decreasing the number of unnecessary invasive biopsies, and guiding lesion management.

Text

2019-10-08

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/71863

Craniofacial Science

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/