Demographic study of 366 cases of oral leukoplakia and immunohistochemical analysis - An institutional study

It has been reported that oral squamous cell carcinoma (OSCC) is associated with the presence of potentially malignant disorders (PMDs) in 15%-48% of cases. Among PMDs, oral leukoplakia (OL) is the most common, with 16%-62% of cases associated with OSCC. Hence, in the present study, we have analyzed demographic data and re-evaluated immunohistochemical (IHC) data of OL cases and aimed to correlate the clinical, histopathological and IHC aspects of OL.

The data of histopathologically diagnosed cases of OL were retrieved from the archives. These data were further evaluated for age, gender, duration, site, size, side, habits, clinical staging and histopathological grading. IHC re-evaluation of OL tissues was done using epithelial cadherin (E-cadherin), n = 20; human MutL homolog 1 (hMLH1), n = 30; CD1a (n = 30); vimentin (n = 30); Ki-67 (n = 30); heat shock protein-70 (HSP-70), n = 30; p16^INK4, n = 20; and mucin-1 (MUC1), n = 30. All the results and observations were subjected to descriptive statistical analysis.

The male: female ratio was 7.5:1; right side and buccal mucosa were more commonly affected. The duration of the lesion ranged from 1 to 30 years. One hundred and twelve patients were habituated to tobacco chewing, while 171 patients came with a combined habit of smoke and smokeless tobacco usage. Clinically, most of the lesions were of stage 2 while histopathologically they were of mild dysplasia. There was a decrease in the immunoexpression of E-cadherin, hMLH1 and CD1a, while there was an increase in the immunoexpression of vimentin, Ki-67, HSP-70, MUC1 and p16^INK4.

The study of different biomarkers such as cytoplasmic, membranous and nuclear in OL will help in better understanding and application of a reliable marker for diagnostic and prognostic purpose.