Prognostic significance of CD44v6, p63, podoplanin and MMP-9 in oral squamous cell carcinomas

Objectives To analyse the expression of the CD44v6, p63, podoplanin and MMP‐9, and their prognostic significance in patients with oral squamous cell carcinomas (OSCC). Material and methods Immunohistochemistry technique was performed on 60 OSCC for detection of CD44v6, p63, podoplanin and MMP‐9 proteins. Extent and intensity of staining were evaluated in tumour cells and were compared with patients' clinical–pathological characteristics and survival. Results CD44v6 expression was detected at the membrane of tumour cells of 94% cases. Nuclear expression of p63 protein was present in 96.5%. Podoplanin was observed at the membrane of tumour cells of 94% cases. MMP‐9 was found in the cytoplasm of tumour cells in 83.7% cases. A high level of expression (67%–89%) in all four proteins was noted. Podoplanin was associated with the expression of MMP‐9 (P = 0.010) and both were associated with lymph node metastasis (P = 0.011 and P = 0.018, respectively). Co‐expression of podoplanin/MMP‐9 was an adverse independent prognostic factor for cancer‐specific survival (P = 0.008) and recurrence‐free survival (P = 0.042). Conclusion Podoplanin and MMP‐9 together could contribute to tumour progression and dissemination of OSCC. Their combined overexpression showed an adverse effect on survival, suggesting that they could be regarded as important prognostic biomarkers in OSCC.