Premium
AgNOR cut‐point to distinguish mild and moderate epithelial dysplasia
Author(s) -
Chattopadhyay Amit,
Ray Jay G.
Publication year - 2008
Publication title -
journal of oral pathology and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 83
eISSN - 1600-0714
pISSN - 0904-2512
DOI - 10.1111/j.1600-0714.2007.00585.x
Subject(s) - dysplasia , parametric statistics , receiver operating characteristic , gold standard (test) , bootstrapping (finance) , confidence interval , medicine , point (geometry) , cut point , concordance , epithelial dysplasia , statistics , pathology , nuclear medicine , mathematics , geometry , econometrics
Background: Distinguishing mild and moderate epithelial dysplasia is difficult and controversial. We demonstrated earlier that silver‐stainable nucleolar organizer region (AgNOR) is a simple, inexpensive and quantifiable method which can standardize this distinction reliably. Objective: To establish a cut‐point mean AgNOR count for epithelial dysplasia validated by bootstrapping. Methods: One hundred oral leukoplakia biopsies at Dr R. Ahmed Dental College, Kolkata, India, examined for epithelial dysplasia using standard method (gold standard) were assessed for their mean AgNOR counts. A cut‐point was selected employing receiver operating characteristic (ROC) curve. This estimate was stabilized by 10 000 resamples (with replacement) using parametric and non‐parametric bootstrap, a Monte Carlo statistical method, corrected for bias to estimate standard errors (SE) of cut‐point. Results: Area under the curve (AUC) was 74%; non‐parametric method suggested mean AgNOR cut‐point = 2.42 AgNORs/nucleus; parametric method suggested cut‐point = 2.57. The cut‐point 95% confidence intervals (CIs) (bias corrected and accelerated) from parametric method (2.31; 2.66) was lower than non‐parametric (2.43; 2.82). Conclusion: Applying a conservative paradigm, taking the lowest of all bootstrap 95% CIs, we suggest that mean AgNOR count of 2.3 be used as a cut‐point for distinguishing between mild and moderate dysplasia. This strategy will provide an inexpensive, meaningful, definitive, reproducible and consistent diagnostic test for epithelial dysplasia.