Role of the human papillomavirus in malignant transformation of oral leukoplakia distinct from oropharyngeal squamous cell carcinoma: A study of 76 patients with internal-control specimens.

OBJECTIVE

This study sought to investigate the role of human papillomavirus (HPV) in the carcinogenesis of oral leukoplakia (OLK), with the oral cavity as the site of interest.

STUDY

DESIGN

A total of 76 patients (152 specimens) were enrolled in the study. The patients were divided into 2 groups: the malignant transformation of OLK (OLK-MT) group and the non-malignant transformation of OLK (OLK-non-MT) group. HPV reverse dot blot analysis, HPV DNA polymerase chain reaction (PCR), and p16INK4A immunohistochemistry (IHC) were used to determine HPV infection status.

RESULTS

Transformation of OLK commonly occurred in the lateral/ventral tongue, buccal mucosa, and gingiva. On the basis of the initial analysis of specimens, only 5.3% (4 of 76) of patients were found to be HPV-16 positive, and these patients' final specimens yielded negative results. Overexpression of p16INK4A in the dysplastic stage was associated with the transformation of OLK (P = .013; odds ratio = 3.544).

CONCLUSIONS

Transformation of OLK was common in patients who are elderly, in females, and in nonsmokers/nondrinkers; lesions were located in the lateral/ventral tongue, with dysplasia and overexpressed p16INK4A seen during the initial stage. HPV may be an opportunistic infection in the oral cavity and may not be a cause of malignant transformation of OLK. p16INK4A expression, which initially increases and then diminishes or disappears, may be an early predictor of malignant transformation.