Expression of Human Papillomavirus and the p16 Gene in Oral Potentially Malignant Disorders (OPMD): a Comparative Study With Oral Squamous Cell Carcinoma.

BACKGROUND: The incidence of oral squamous cell carcinoma (OSCC) of the tongue is increasing in the younger population without traditional risk habits that lead researchers to find other related factors such as diet and viruses, especially human papillomavirus (HPV). It is noteworthy that many OSCCs develop from oral potentially malignant disorders (OPMDs). Correct diagnosis and timely management of OPMDs may help to prevent malignant transformation, and therefore it is worth seeing the involvement of HPV in OPMDs and oral cancers, as the preventive and curative measures in HPV-induced cancer types are different from the conventional types of OPMDs and OSCCs. Therefore, the main objective of this study was to identify a relationship between HPV and p16 in OPMDs and compare it with OSCC. METHODS: This study was conducted on 83 cases of known OSCCs and OPMDs (oral submucous fibrosis, leukoplakia, and oral lichen planus). Assays, such as polymerized chain reaction (PCR) and reverse transcription-PCR, were carried out for HPV and p16 . The results were compared with clinical information and with the literature. The results were analyzed using SPSS 16.0 for windows. RESULTS: P16 expression was mostly seen in males than in female patients. Out of 21 cases of keratosis with dysplasia, 19% expressed p16 . Of 26 oral lichen planus patients, 29% showed the p16 gene with immunohistochemistry. Interestingly, a high percentage of OSF cases expressed p16 (48.27%). Minimal expression was observed in OSCC (6.25%). HPV DNA was detected in 2.4% of the total sample. Both p16 and HPV were detected in a single case of OSCC. OPMDs expressed a significant amount of the p16 gene by immunohistochemistry and reverse transcription-PCR technique when compared with malignant lesions, suggesting a possible inactivation of the p16 gene. HPV and p16 are mostly negative in our OSCC sample, exhibiting low prevalence. CONCLUSIONS: OPMDs expressed a significant amount of the p16 gene when compared with malignant lesions, suggesting a possible inactivation of the p16 gene. Although OSF expressed p16 , HPV was not detected, suggesting that over-expression could be independent of HPV. OSCC shows low HPV prevalence.

A validated predictive model for risk of nodal metastasis in node negative oral squamous cell carcinoma of the buccal mucosa and tongue.

BACKGROUND: Lymph node metastasis in oral squamous cell carcinoma (OSCC) is influenced by clinical and histopathological variables. The aim of this study was to develop a simple model to predict nodal metastasis of OSCC in clinically negative necks (cN0). METHODS: Data from patients who underwent surgery for treatment of OSCC of the tongue or buccal mucosa with neck dissection were used for model development and validation. RESULTS: Nodal metastasis was significantly associated with gender, age, tumor size, site, pattern of invasion and depth of invasion on univariate analysis. All the five variables except age were retained at the variable selection step of the model development and were used in the final model because it was not significant at 0.10 significance level after adjusting for other variables. Regression coefficients of the model were used to estimate risks of nodal metastases for each combination of clinicopathological characteristics. A 10-fold cross-validation was used to assess the model. The average of the resultant 10 AUCs (along with its 95% confidence interval estimated using bootstrap) was used as the overall validated measure of the model. A risk chart was produced using probability of nodal metastasis predicted by the model for each combination of five characteristics. The model's ability to identify patients with nodal metastases as assessed by the area under the ROC curve (AUC) was 0.752. CONCLUSION: The model based on established clinicopathological variables has been internally validated on a large cohort of patients and offers practicability for use in OSCCs of the tongue and buccal mucosa.

Epithelial Dysplasia at Excision Margins of Oral Squamous Cell Carcinoma: A Review on Relationship to Clinicopathological Parameters and Prognosis.

BACKGROUND: Epithelial dysplasia (ED) at oral cancer excision margins is a frequent finding. Dysplastic epithelium at excision margins may not be similar to dysplasia in Oral potentially malignant disorders (OPMD) as malignant transformation has already taken place. Therefore, management of ED at excision margins should be different to that of OPMD. ED creates a dilemma in relation to further management of cancer patients, since there are no accepted guidelines. Therefore, the objective of this review is to analyze  existing literature and to arrive at evidence based recommendations for the management of ED at excision margins. METHODS: A comprehensive string was run on PubMed, Medscape and Medline. The final outcome included 113 studies. Finally, the most relevant 10 articles were critically assessed for inclusion and exclusion criteria against various parameters. RESULTS AND CONCLUSIONS:   Severe and Moderate ED need re-excision in order to improve prognosis. There is not enough sound evidence for the management of Mild ED at excision margins of oral squamous cell carcinoma. Guidelines for the management of ED at excision margins should be formulated after comprehensive multi center studies using lager cohorts of patients.
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Clinically malignant exophytic lesions in the background of oral submucous fibrosis: report of five cases.

Oral submucous fibrosis (OSF), a common disease in South Asia, is a chronic disorder, and there is a lack of proper scientific understanding about many aspects of the disease. Carcinogenesis in the background of dense fibrosis is considered the most significant aspect of the disease that needs investigation, as the transformation rate is also remarkable compared with other oral potentially malignant disorders. Verrucous growths are a common finding in patients with OSF. We highlight a group of patients who presented with clinically malignant verrucous growths. However, despite the highly suspicious clinical appearance, there was no histologic evidence of invasion. This subgroup of patients with OSF and the inability of the lesion to invade the underlying corium need to be investigated.