A low percentage of HER‐2 amplification whereas indicates poor prognosis in salivary carcinoma ex pleomorphic adenoma: a study of 140 cases. (16th July 2016) - Xia, Liang
Abstract : Background: Human epidermal growth factor receptor 2 ( HER‐2 ) has been found in many malignant tumours including salivary malignancy. HER‐2 ‐targeted therapy has been applied in the treatment of HER‐2 ‐overexpressing carcinoma. The aim of this study was to determine the status of HER‐2 in salivary invasive carcinoma ex pleomorphic adenoma (ICXPA) in a relatively large Chinese sample, which may provide HER‐2 ‐targeted therapy with profound support in the future. Methods and results: We collected 140 ICXPAs and their related clinicopathological and follow‐up data. All cases were examined for HER‐2 expression by immunohistochemistry and gene amplification by fluorescence in situ hybridization, if necessary. The study showed that the ratio of HER‐2 positivity was only 25% (35/140) in all cases, but the positive ratio in ICXPAs with luminal differentiation for malignant component (32/79, 40.5%) was much higher than that in cases with non‐luminal differentiation (3/61, 4.9%). The overexpression of HER‐2 was closely associated with gender, histological grade and N stage. HER‐2 ‐positive tumours conferred short overall survival time ( P = 0.036) and short disease‐specific survival time ( P = 0.042) in patients, but HER‐2 status was not an independent predictor of prognosis. Conclusions: Human epidermal growth factor receptor 2 amplification is significantly associated with cell differentiation of the malignant component in ICXPA and it implies an unfavourable prognosis. Although HER‐2 positivity is not common in the tumour, HER‐2‐ targeted therapy for those HER‐2 ‐positive patients is still worth expecting.