Histological examination of biopsy shows usefulness in the diagnosis of vocal cord leukoplakia; however, in considerable amount of cases, the examination cannot provide definitive diagnosis of malignancy from benign conditions such as hyperplasia and dysplasia. The present work therefore was aimed to identify clinicopathological factors and molecular markers predictive of recurrence and malignant transformation of vocal cord leukoplakia.
Clinical data of 555 cases of vocal cord leukoplakia enrolled from July 1999 to June 2014 were analyzed. The cohort consisted of keratosis (n = 137), hyperplasia (n = 139), dysplasia (n = 177), and primary (n = 10) and invasive (n = 46) carcinoma. Correlations between patients’ backgrounds, clinicopathological factors, molecular markers (p53, p16, Ki67, cytokeratin, and proliferating cell nuclear antigen), and histology backgrounds were examined using by Pearson Chi-squared or Fisher exact test. Reflux symptom index (RSI) and reflux finding score (RFS) before and after treatment were compared using Wilcoxon signed-rank test. Risk factors for disease recurrence were identified using Cox proportional hazards models of multivariate analysis. Time to recurrence was analyzed using log-rank test of Kaplan–Meier method.
In the present cohort, alcohol drinking was found associated with GRBAS grade (P = .0258) and the site (P = .0298) of leukoplakia. For the different disease types, chief complaint (P = .0179), GRBAS grade (P = .0101), mucosal wave (P < .0001), and molecular markers p53 (P < .0001) and Ki67 (P < .0001) were identified as correlates. RSI and RFS were significantly lowered by surgical intervention. A single side of leukoplakia was predictive of a lower risk of recurrence (odds ratio, 0.378; 95% confidence interval, 0.197–0.723; P = .0033). Absence of mucosal wave was associated with a shorter time-to-recurrence (P = .0357).
The present work identified clinicopathological factors and molecular markers associated with the different histology of vocal cord leukoplakia, and also the prognostic factor for the low risk of recurrence after surgery.