Expression of HER3 in HER2-positive breast cancer and its relationship with clinical prognosis / 中华内分泌外科杂志

ABSTRACT

Objective To explore the expression of human epidermal growth factor receptor -3( HER3) in human epidermal growth factor receptor-2(HER2)-positive breast cancer and its relationship with the therapeutic effect of trastuzumab and clinical prognosis .Methods Clinicopathological characteristics of 235 HER2-positive breast cancer patients undergoing surgery in Jiangsu Cancer Hospital from Jan .2007 to Jun.2012 were analyzed retrospectively.The expression of HER3 was detected using immunohistochemisty staining .The expression of HER3 and its correlation with the clinicopathological characteristics were analyzed .All patients were followed-up to find out the impact of HER3 on the disease free survival and the therapeutic effect of trastuzumab .Results The positive rate of HER3 in Luminal B ( HER2 +) and HER2-overexpressing breast cancer was 100/135 (74.1%), and 85/100(85%)respectively.The difference had statistical significance (P<0.05).The histolog-ical grading and the lymph node metastasis were significantly different in Luminal B ( HER2+) breast cancer .The tumor volume , histological grading and lymph node metastasis were significantly different in HER 2-overexpressing breast cancer .The 5-year disease free survival of HER 2-positive breast cancer patients with negative HER 3 was higher than that with positive HER3.The non-relapse survival time was not significantly different between the pos-itive and negative HER 3 expression in Luminal B ( HER2+) breast cancer patients receiving trastuzumab treat-ment , but was significantly different in HER 2-overexpressing breast cancer patients .Conclusions HER3 is cor-related with unfavourable prognosis in HER 2-positive breast cancer .The treatment targeting HER3 may improve the clinical prognosis of both HER 2-positive and HER3-positive breast cancer patients .The HER2-overexpressing breast cancer patients with negative HER 3 may benefit more from trastuzumab treatment .