In situ assessment of intraepithelial neoplasia in hamster trachea epithelium using angle-resolved low-coherence interferometry

Optical spectroscopy was used to evaluate the transformation of nuclear morphology associated with intraepithelial neoplasia in an animal model of carcinogenesis. In this pilot study, we have assessed the capability of angle-resolved low-coherence interferometry (a/LCI) to monitor in situ the neoplastic progression of hamster trachea epithelial tissue. By using the depth resolution made possible by coherence gating, the a/LCI system has been adapted to the unique geometry of the hamster trachea to allow us to extract useful nuclear morphometric information from cells in the epithelial layer without the need for exogenous staining or tissue fixation. Analysis of a/LCI nuclear morphology measurements has identified two important biomarkers of neoplastic transformation in hamster trachea epithelium, the size and the refractive index of epithelial cell nuclei. By comparing the a/LCI measurements of these two biomarkers to pathologic classification, we distinguished nuclear morphology changes for normal tissue, low-grade dysplasia, and high-grade dysplasia. Given its previous usefulness for tracking neoplastic change through nuclear morphometry measurements, the a/LCI technique may prove to be a useful tool in evaluating chemopreventive agents in future studies of hamster trachea epithelium.