Role of Candida infection in the malignant transformation of oral leukoplakia: A systematic review of observational studies

The aim of this systematic review was to investigate the malignant transformation of oral leukoplakia (OL) infected with Candida. Literature search was conducted using Medical Subject Heading terms ‘leukoplakia’, ‘neoplasms’, ‘Candida’, ‘malignant transformation’ and ‘oral’ and included all results until February 2017. The initial search identified 372 articles, which was consolidated to 16 articles after applying inclusion and exclusion criteria. The occurrence of candidal infection in OL ranged from 6.8% to 100.0%. Only 3 of 16 studies reported malignant transformation rates of leukoplakia with Candida infection. The overall malignant transformation rates reported in these studies were 2.5%, 6.5% and 28.7%. This review supports the contention that candidal infection promotes cellular and dysplastic changes in OL. However, further follow-up studies are recommended to confirm the role of Candida infection in malignant transformation of OL lesions.