Immunohistochemical Investigation of Predictive Biomarkers for Mandibular Bone Invasion in Oral Squamous Cell Carcinoma.

The accurate preoperative determination of the extent of mandibular resection remains a challenge for the surgeons. The purpose of the present study was to immunohistochemically investigate predictive markers for histological bone invasion of oral squamous cell carcinoma (OSCC). The medical records of primary OSCC patients with mandibular bone contact in preoperative computed tomography scans between January 2003 and December 2017 were retrospectively reviewed and an immunohistochemical investigation was performed. Forty-five OSCC patients with mandibular bone contact radiographically were included in this study. Histopathologically, infiltrative bone invasion was observed in 19 patients (42.2%) and compressive bone invasion in 15 (33.3%). A correlation was noted between the histological pattern of bone invasion and mode of invasion (chi-squared test, p < 0.05). At the tumor surface, a correlation was observed between the expression of IL-6 and bone invasion (the Wilcoxon test, p < 0.05), although the expression was so weak. At the bone contact area, the expression of both ɑ-SMA and OPG correlated with infiltrative bone invasion (ɑ-SMA; the Wilcoxon test, p < 0.05, OPG; p < 0.05). These results suggest that predictive markers for aggressive (infiltrative) bone invasion in OSCC patients with a higher mode of invasion are the expression of ɑ-SMA and OPG.