Abstract PR-05: Alterations in tissue autofluorescence using spectroscopy in high-risk oral lesions

Abstract

Abstract High-risk oral lesions can be sometimes difficult to discriminate from reactive oral lesions, which are commonly seen within community settings. New tools need to be developed to aid in screening and early detection of high-risk lesions. The assessment of alteration in tissue autofluorescence using spectroscopy has demonstrated promising results in distinguishing cancerous from normal tissue at many organs and sites; however, there is limited information on its usage to distinguish reactive lesions (as seen by both white-light and autofluoescence imaging) from cancerous/precancerous lesions. Objectives of this study are: 1) to collect autofluorescence spectra from normal mucosa, mucosa with high-risk histological change and those with chronic inflammation under different excitation wavelengths of light, and 2) to compare the change in tissue autofluorescence in different exciting wavelengths among these oral mucosal lesions. Methods: Patients with high-risk oral lesions and inflammatory conditions were recruited from the Dysplasia Clinics of the BC Oral Cancer Prevention Program. Spectroscopic measurements were taken using a fiber optic probe of a Remiscope (Remicalm, LLC; Houston, TX). Three excitation wavelengths were used: 436 nm, 405 nm, and 355 nm. Percent loss of peak emission intensity (%PEI) was measured by comparing the PEI of the lesional and contralateral normal areas. Differences in %PEI between groups were compared using unpaired t-test. Results: From June to September 2009, 102 spectroscopic measurements were recorded from 17 patients (cancer, 5; dysplasia, 6; inflammation, 6). Among these, loss of tissue autofluorescence under 436 nm, 405 nm, and 355 nm was observed in all cases. When comparing the %PEI between cancer and dysplasia groups, increased loss was seen in the cancer group at all three excitation wavelengths, especially under 355 nm and 405 nm excitations (P = 0.023 and 0.045 respectively). When comparing to the inflammation group, there is almost the same degree of loss observed between cancer and inflammation groups in all 3 excitation wavelengths. Interestingly, there is a significant difference in %PEI observed between dysplasia and inflammation group under 436 nm and 355 nm excitations (P = 0.005 and 0.022 respectively) but no statistical difference under 405 nm excitation. Conclusions: This is the first study to use 3 different excitation wavelengths of light to examine the spectra of oral cancerous, precancerous, and specifically inflammatory oral lesions (as seen by both white-light and autofluoescence imaging). This device has shown its potential to provide an objective, sensitive approach to distinguish precancers from those commonly seen within community settings caused by chronic inflammation. (Supported by grant R01 DE17013 from the National Institute of Dental and Craniofacial Research and grant CCSRI-20336 from Canadian Cancer Society Research Institute. CFP is supported by a Clinician Scientist Award from the Canadian Institutes of Health Research and a Scholar Award from the Michael Smith Foundation for Health Research). Citation Information: Cancer Prev Res 2010;3(1 Suppl):PR-05.