High expression of protein tyrosine kinase 7 in oral squamous cell carcinoma: Clinicopathological correlation and prognosis relevance

Background: The purpose of this study was to evaluate the association between the immunohistochemistry (IHC) of protein tyrosine kinase 7 (PTK7) expression and clinicopathological factors of oral squamous cell carcinoma (OSCC). Methods: Tissue specimens were obtained from 80 patients with primary OSCC. IHC scoring was conducted according to the rate of positive cell and staining intensity. We used the IHC score to classify the degree of PTK7 expression and evaluate clinicopathological factors and prognosis. Results: The number of the high expression group (INC Score 2 or 3) was 45 cases and that of the low expression group (IHC Score 0 or 1) was 35 cases. A significant difference between high expression and low expression groups was found in the N category (p = .008), degree of differentiation (p < .001), and pattern of invasion (p < .001). In accordance with the exacerbation of OSCC with respect to three parameters (N category, degree of differentiation, and pattern of invasion), the ratio of high expression of PTK7 increased. The overall 5-year survival rate was 59.3% in the high expression group and 87.3% in the low expression group (p < .05). The pathological prognostic signs affecting overall survival were evaluated by univariate analysis and multivariate analysis with Cox proportional hazards model and showed an association with lymph node metastasis and invasion patterns. Conclusion: This study suggests that a high IHC score of PTK7 is a potential biomarker for predicting potential metastasis.