Spectral Slope from the Endoscopically-Normal Mucosa Predicts Concurrent Colonic Neoplasia: A Pilot Ex-Vivo Clinical Study

Abstract
Purpose: We previously reported that analysis of histologically normal intestinal epithelium for spectral slope, a marker for aberrations in nanoscale tissue architecture, had outstanding accuracy in identifying field carcinogenesis in preclinical colorectal cancer models. In this study, we assessed the translatability of spectral slope analysis to human colorectal cancer screening. Methods: Subjects (n = 127) undergoing colonoscopy had spectral slope determined from two endoscopically normal midtransverse colonic biopsies using four-dimensional elastic light-scattering fingerprinting and correlated with clinical findings. Results: Four-dimensional elastic light-scattering fingerprinting analysis showed the submicron particles size progressively shifted toward larger sizes in subjects harboring neoplasia. There was a corresponding decrease in spectral slope values from the endoscopically normal mucosa in subjects harboring adenomas (n = 41) and advanced adenomas (n = 10), compared to neoplasia-free subjects(P≤ 0.00001). These factors did not appear to be confounded by either age or adenoma location. For detecting advanced adenomas, spectral slope had a negative and positive predictive value of 95 percent and 50 percent respectively. Conclusions: We demonstrate, for the first time, that spectral slope in “normal” mucosa can accurately risk-stratify patients for colonic neoplasia. This proof of concept study serves to underscore the promise of four-dimensional elastic light-scattering fingerprinting analysis for colorectal cancer screening.