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 twuor 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.