Podoplanin expression predicts prognosis in patients with oral squamous cell carcinoma treated with neoadjuvant radiochemotherapy.

Despite new therapeutic approaches patients with advanced oral squamous cell carcinoma still have a dismal prognosis. The main factor contributing to this problem is locoregional failure due to a lack of response to treatment. Several trials have proven the effect of neoadjuvant radiochemotherapy followed by radical surgery in comparison to primary surgery followed by adjuvant radiochemotherapy. No reliable parameters have been identified so far to predict response to radiochemotherapy. The aim of our study was to assess whether podoplanin expression in pretreatment biopsies could serve as a biomarker to predict the host response to neoadjuvant radiochemotherapy. In this retrospective study, podoplanin expression was examined in a set of 63 patients with oral squamous cell carcinoma by immunohistochemistry. We analyzed associations between the level of podoplanin expression and various clinicopathologic parameters, including response to radiochemotherapy, clinical and histological N-status. Furthermore we evaluated the effects of these parameters on overall survival and on locoregional control in univariate and multivariate analysis. The χ(2)-test revealed that high expression of podoplanin in pretreatment biopsy material was associated with non-regression of the tumor (p=0.013) and poor overall survival (p<0.001). Five-year survival rates of 92.9% for patients with weak expression and 15.0% for high expression were revealed. Podoplanin expression was also significantly associated with ypN status (p=0.004) and ypUICC status (p<0.001). We concluded that podoplanin might serve as a factor to predict treatment response in oral squamous cell carcinoma treated with neoadjuvant platin-based radiochemotherapy as well as a prognostic factor for overall survival and locoregional control.