Immunohistochemical Expression of Podoplanin in Clinical Variants of Oral Leukoplakia and Its Correlation With Epithelial Dysplasia

Molecular Biomarkers of Malignant Transformation in Head and Neck Dysplasia

Head and neck squamous cell carcinoma (HNSCC) and its treatments are associated with substantial morbidity, often resulting in cosmetic deformity and loss of physiologic functions including speech and swallowing. Despite advancements in treatment, 5-year survival rates for mucosal malignancies remain below 70%. Effective prevention of HNSCC demands an understanding of the molecular pathways of carcinogenesis. Specifically, defining features of pre-cancerous dysplastic lesions that indicate a better or worse prognosis is necessary to help identify patients who are likely to develop a carcinoma and allow a more aggressive approach to management. There remains a need for identification of biomarkers that can provide both early prognostic and predictive value in clinical decision-making by serving as both therapeutic targets as well as predictors of therapy response. Here, we comprehensively review the most frequently altered molecular biomarkers of malignant transformation in head and neck dysplasia. These markers are involved in a wide range of cellular processes in head and neck carcinogenesis, including extracellular matrix degradation, cell motility and invasion, cell-cell adhesion, solute transport, immortalization, metabolism, the cell cycle and apoptosis, transcription, and cell signaling.

Podoplanin Expression Independently and Jointly with Oral Epithelial Dysplasia Grade Acts as a Potential Biomarker of Malignant Transformation in Oral Leukoplakia

Our aim was to evaluate the expression of biomarkers, CD44v6, CD147, EGFR, p53, p63, p73, p16, and podoplanin in oral leukoplakias (OL) and to assess their potential for prediction of malignant transformation (MT). We analyzed the expression of CD44v6, CD147, EGFR, p53, p63, p73, p16, and podoplanin by immunohistochemistry in 52 OL, comprised of 41 low-grade (LG) dysplasia and 11 high-grade (HG) cases. Twelve healthy normal tissues (NT) were also included. Univariate and multivariate analysis were performed to evaluate any association with MT. Variable expression among the studied markers was observed, with a significant increase of high expression from NT to LG and HG cases in CD44v6 (p = 0.002), P53 (p = 0.002), P73 (p = 0.043), and podoplanin (p < 0.001). In multivariate analysis, cases with high podoplanin score showed a significant increased risk of MT (HR of 10.148 (95% CI of 1.503−68.532; p = 0.017). Furthermore, podoplanin combined with binary dysplasia grade obtained a HR of 10.238 (95% CI of 2.06−50.889; p = 0.004). To conclude, CD44v6, p53, p73, and podoplanin showed an increasing expression along the natural history of oral carcinogenesis. Podoplanin expression independently or combined with dysplasia grade could be useful predictive markers of MT in OL.

DEC1: a potential biomarker of malignant transformation in oral leukoplakia

The purpose of this study was to analyze the differential expression of DEC1 in oral normal mucosa (NM), oral leukoplakia (OLK) and oral squamous cell carcinoma (OSCC). Surgically excised specimens from patients with OLK (n = 47), OSCC (n = 30) and oral normal mucosa (n=11) were immunostained for DEC1. The expression of DEC1 protein was evaluated, and its association with the clinicopathological features was analyzed. The expression of DEC1 in NM, OLK and OSCC tissues increased in turn, and significant differences were observed among the groups (P < 0.0001). In terms of the association between DEC1 expression and epithelial dysplasia, DEC1 expression was lower in hyperkeratosis without dysplasia (H-OLK) than in OLK with moderate to severe dysplasia (S-OLK), and these differences were significant (p < 0.05). The expression of DEC1 in OSCC with OLK was significantly higher than that in OSCC without OLK (p < 0.01). Therefore, DEC1 could be a potential biomarker of malignant transformation in the carcinogenesis of OSCC, which may provide a new research direction for the transformation of oral potentially malignant disorders (OPMDs) into OSCC.

Prognostic Potential of the Expression of Podoplanin (D2-40) Within Cells of Squamous Cell Carcinoma of the Larynx and Hypopharynx

Background

Podoplanin (D2-20) stains immunohistochemically lymphatic vessels, regular mesothelium and tumor cells of different tumors, e.g. malignant mesothelioma or seminoma. In squamous cell carcinoma (SCC), the marker has been described as variously expressed.

Methods

This study has investigated the value of the immunohistochemical analysis for the prognostic relevance of the expression in 119 SCCs of the larynx and hypopharynx. The clinical data and documentation of follow-up for at least 5 years were available.

Results

The collective showed the expected distribution of patient age with accentuation of the male sex and a balanced spread of tumor stages including nodal status. The immunohistochemical stain intensity (negative, weak or strong) and the distribution (equal versus focal) were evaluated. In addition, the accentuation of the staining reaction was separately examined at the border of invasion. SCCs with a strong expression of podoplanin were associated with an unfavorable prognosis. A comparison of grouped cases showed a trend emerging with borderline results (negative to weakly positive, P = 0.51; negative to strongly positive, P = 0.054; weakly positive to strongly positive, P = 0.17). The staining at the border of invasion had no statistical effect on overall survival. Multivariate survival statistics however showed that lymphonodal metastasis and a reaction with podoplanin in tumor cells are associated with significant worse prognosis.

Conclusion

In summary, regardless of the exact function of podoplanin in the process of cell migration and tumor progression, an immunohistochemical identification of expression in tumor cells of SCC of the larynx and hypopharynx can give additional information about the expectable prognosis.

Podoplanin expression as a predictive marker of dysplasia in oral leukoplakia

PURPOSE

Recent studies have emphasized the role of podoplanin in oral lesions at risk of malignant transformation. We investigated a group of oral leukoplakias (OLs) to determine a possible relation between altered podoplanin expression and dysplasia, and to compare the results with those obtained by other, widely used biomarkers.

MATERIALS AND METHODS

The population consisted of 40 consecutive patients with a clinical and histological diagnosis of OL. Thirty-two OLs did not show dysplasia, whereas eight lesions presented with dysplasia. Immunohistochemical expression of podoplanin, p53 and Ki67 was analyzed in all samples.

RESULTS

All three biomarkers were positive in seven of eight dysplastic OLs. Among the 32 OLs without dysplasia, Ki67 and p53 showed positive values in 21 and 10 samples respectively, whereas podoplanin was positive in only one case. Multiple logistic regression showed that podoplanin was the most powerful variable (Chi square 9.77; p < .01) statistically related to the presence of dysplasia. In addition, podoplanin showed a higher specificity value (96.87%) than Ki67 (34.37%) and p53 (68.75%).

CONCLUSION

Podoplanin seems to be a reliable means of discriminating lesions with epithelial dysplasia and could be introduced in routine practice as a marker to discriminate OLs at risk of developing cancer.