Malignant Transformation Rates of Vocal Fold Leukoplakia Stratified by Dysplasia Grade: A Systematic Review and Meta‐Analysis
Rawaha Husam Al‐Deen, Shaahid Mohammed Ashraff, Mohammed Bilal Aziz, Humzah Hameed, Haleema Sadia Adil, Azfar Javed, Kalani Kuruppu, Hamad Khan, Farhan AhsanABSTRACT
Objective
To perform a systematic review of rates of malignant transformation of vocal fold leukoplakia as per grades of dysplasia, to support clinician follow‐up strategies and management and to make an assessment on the 2‐tiered system against the previous 3‐tiered system.
Data Sources
PubMed, Embase, Scopus and Web of Science.
Review Methods
The JBI critical appraisal tool was used to assess included studies for bias. Rates of and time to malignant transformation were extracted from each study.
Results
Thirty studies containing 3714 patients with dysplastic lesions were included. Most used WHO 2005 grading, with limited WHO 2017 use. Meta‐analysis of 17 studies showed that under WHO 2005, malignant transformation occurred in 7.3% of patients with mild dysplasia (95% CI: 4.0%–10.6%), 19.2% of patients with moderate dysplasia (95% CI: 12.4%–26.1%) and 29.4% of patients with severe dysplasia or carcinoma in situ (95% CI: 21.4%–37.4%), all p < 0.001. Severe dysplasia carried a higher risk than mild (RR = 2.13; 95% CI 1.67–2.71, p < 0.001) and moderate dysplasia (RR = 1.24; 95% CI 1.01–1.52, p = 0.041); moderate exceeded mild (RR = 1.68; 95% CI 1.31–2.16, p < 0.001). Under WHO 2017, high‐grade exceeded low‐grade dysplasia (RR = 1.94; 95% CI 1.55–2.42, p < 0.001).
Conclusion
Laryngeal dysplasia is at greater risk of malignant transformation as the grade increases, supporting greater surveillance at higher grades. A layer of follow‐up could be viewed as being lost in the 2017 system with moderate dysplasia maintaining its own risk profile when comparing RRs between high and moderate dysplasia. However, as moderate dysplasia presents a significant risk profile, it can be argued that classifying it as higher grade in the new system has credence. Future studies should standardise follow‐up intervals and data reporting and assess the effect of risk‐factor control.