Autofluorescence imaging as a noninvasive tool of risk stratification for malignant transformation of oral leukoplakia: A follow-up cohort study

There is few longitudinal study on oral potentially malignant disorder (OPMDs) focusing on oral leukoplakia (OLK) with clinical endpoints to investigate the role of autofluorescence imaging (AFI) for surveilling the malignant transformation.Based on our previous prospective diagnostic study enrolled 517 OPMD patients, 184 OLK patients were retrieved to further investigate the role of AFI using VELscope in predicting malignant transformation. During a median follow-up period of 44 months, 19 (10.33%) developed into oral cancer.OLK patients were divided into loss of autofluorescence (LAF, n = 124) and retention of autofluorescence (RAF, n = 60) groups according to the results of AFI. Interestingly, difference between malignant transformation rate (MTR, 14.52%) of group LAF and overall MTR (10.33%) was not significant, but MTR (1.67%) of group RAF was significantly lower than overall MTR. Kaplan-Meier and Cox-regression analyses revealed that LAF could not directly distinguish the high-risk lesions, but RAF significantly discriminate the low-risk lesions. Importantly, time-dependent ROC curve analysis found that the sensitivity and negative predictive value (NPV) of AFI for the prediction of malignant transformation was 100% and 100% (2-year follow-up), 94.7% and 98.3% (5-year follow-up), respectively. Also, calibration curve and decision curve analyses showed high levels of predictive value and clinical relevance.This follow-up cohort study firstly evaluated AFI using VELscope for risk stratification of OLK malignant transformation. Whether conservative management is appropriate for OLK patients with RAF imaging due to minimal rate and risk of malignant transformation and great specificity and NPV is required to be further investigated.