Pre-operative incisional biopsy of oral squamous cell carcinoma: high podoplanin expression is related to perineural invasion and may be a useful predictor of disease progression

Objective: Immunohistochemical analysis of podoplanin expression as a pre-operative molecular marker for perineural invasion (PNI) may represent an attractive strategy for surgical management of oral squamous cell cancer (OSCC). We evaluated the relationship between podoplanin expression and PNI in pre-operative incisional biopsies of OSCC. Study Design: After performing pathological staging and histologic and immunohistochemical evaluation of 83 surgical specimens, we performed multivariable logistic regression analysis to examine the relationship between PNI and independent variables. To evaluate the utility of podoplanin immunopositivity for discrimination of PNI status pre-operatively, we calculated the sensitivity, specificity, positive predictive value, and negative predictive value. We performed receiver operating characteristic curve analysis to evaluate the diagnostic accuracy of podoplanin immunopositivity for predicting PNI alone and in combination with age, T stage, N stage, and index site. Results: We observed podoplanin expression in 42 (50.6%) of all the 83 pre-operative incisional biopsies and 29 of the pre-operative biopsies of the 31 (93.5%) postoperative specimens with PNI. The rate of podoplanin expression was significantly higher in patients with pT3 to pT4 stage and pN+ stage disease. Podoplanin positivity in the pre-operative biopsy showed high sensitivity in predicting PNI in the surgical specimen. Conclusion: Podoplanin expression appears to be an independent pre-operative variable significantly related to PNI and a possibly valuable prognostic marker for therapeutical planning and surgical treatment of OSCC.