Human epidermal growth factor receptor‐2 expression in locally advanced rectal cancer: Association with response to neoadjuvant therapy and prognosis

The aim of this study was to determine whether pretreatment status of human epidermal growth factor receptor‐2 (HER‐2) could predict pathologic response to neoadjuvant chemoradiotherapy (nCRT) and outcomes for patients with locally advanced rectal cancer (LARC). A total of 119 patients diagnosed with LARC received standardized multimodal treatment. Their HER‐2 status was determined in pretreatment biopsies by immunohistochemistry (IHC) and FISH. Tumor response was assessed in resected regimens using the tumor regression grade system and TNM staging system. Twenty‐two cases in 119 patients assessed as IHC3+ or IHC2+ plus gene‐amplified were determined as HER‐2 positive. Positive HER‐2 status was not associated with any pretreatment clinicopathologic parameters (P > 0.05). HER‐2 status could not predict pathologic response to nCRT based on downstaging (P = 0.210) and tumor regression grade (P = 0.085) but it provides us with a trend that HER‐2‐positive tumors may be resistant to nCRT. Positive HER‐2 status was significantly associated with poor 5‐year disease‐free survival (P = 0.015) and 5‐year overall survival (P = 0.026). It can act as a worse prognostic factor for LARC patients. HER‐2 status was determined in pretreatment biopsies by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). HER‐2 positivity before nCRT were significantly associated with poor 5‐year disease‐free survival (P = 0.015) and 5‐year overall survival (P = 0.026). HER‐2 status can not predict tumor response to nCRT in LARC, but it provides us with a trend that HER‐2 positive tumor may be resistant to nCRT.