Immunohistochemical Marker Expression in Temporal Bone Squamous Cell Carcinoma.

BACKGROUND The correlation between genomic mutations (or the overexpression of abnormal proteins) and prognosis in temporal bone squamous cell carcinoma (TBSCC) is not clear. We investigated the overexpression of EGFR and p53 as a pathological biomarker for predicting the clinical course of patients with TBSCC. METHODS We performed a retrospective review of 22 TBSCC cases treated in Tokai University Hospital between January 2005 and October 2016. We assessed the overexpression of EGFR and p53 in TBSCC patients through immunohistochemical staining. We also evaluated the association between the overexpression of these proteins and clinicopathological variables, including survival outcomes. RESULTS The primary lesion in all patients was the external auditory canal. Nine (40.9%) patients were EGFR positive, and 9 (40.9%) were p53 positive. The 5-year overall survival rate for EGFR-positive patients (55.6%) was significantly lower (p = 0.043) than that of the EGFR-negative patients (92.3%). CONCLUSION EGFR overexpression in TBSCC patients may be a prognostic biomarker.