Immunohistochemical investigation of biomarkers for predicting adipose tissue invasion in oral squamous cell carcinoma

Abstract

The purpose of the present study was to identify histological biomarkers that could be used to predict adipose tissue invasion by oral squamous cell carcinoma (OSCC). The medical records and preoperative computed tomography scans of patients with primary OSCC with suspected buccal fat pad invasion were retrospectively reviewed, and an immunohistochemical study of candidate predictive biomarkers of adipose tissue invasion (α-SMA, E-cadherin, N-cadherin, FABP4, Col VI, and MMP-11) was carried out. Thirty OSCC patients whose tumors were suspected to be in contact with the buccal fat pad based on preoperative imaging were included in this study. Of these, infiltrative adipose tissue invasion was histopathologically confirmed in 6 patients (20.0 %). The significant higher immunoreactivity of candidate predictive biomarkers was detected in the tumor-buccal fat pad contact area compared to in the tumor surface area.(Pearson’s correlation coefficient test: α-SMA: 0.422, p < 0.05; N-cadherin: 0.476, p < 0.01; FABP4: 0.467, p < 0.01;). In the tumor-buccal fat pad contact area, Col VI immunoreactivity was significantly higher in the OSCC with buccal fat pad invasion than without buccal fat pad invasion (median test, p < 0.01). Furthermore, high α-SMA expression exhibited a tendency towards an association with OSCC with buccal fat pad invasion, as did high FABP4 expression (median test, α-SMA: p = 0.06, FABP4: p = 0.07). These results suggest that the expression levels of α-SMA and FABP4 may be useful biomarkers for predicting aggressive adipose tissue invasion in OSCC.