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Oral carcinoma with perineural invasion has higher nerve growth factor expression and worse prognosis.

BACKGROUND
This study elucidated the association between histopathological factors and the prognosis of oral carcinoma. As the histopathological factors were determined from the surgical specimen and this can only be used for the choices of postoperative regimens, this study also investigated the linkage between prognostic factors and the expression of key molecules to examine the feasibility of markers as predictors.


METHODS
Clinicopathological factors of 101 oral carcinomas were cross-analyzed with disease-free survival. The expression of nerve growth factor (NGF) and its receptor, tyrosine kinase A receptor, was assayed with immunohistochemistry.


RESULTS
Nodal metastasis was the most crucial clinical predictor for disease-free survival. Perineural invasion (PNI) was an independent histopathological predictor for both nodal metastasis (P = 0.004) and disease-free survival (P = 0.019). Patients with advanced tumor and PNI exhibited the high hazard for tumor progression and poor disease-free survival. NGF immunoreactivity in tumors was correlated with PNI (P = 0.005) and neck lymph node metastasis (P = 0.036).


CONCLUSION
Perineural invasion is the indicator of worst prognosis. As NGF immunoreactivity was found to be associated with PNI and nodal metastasis, the NGF immunoreactivity of oral carcinoma revealed by diagnostic biopsy suggests that alternative therapeutic approaches might be appropriate.