结直肠癌HER2免疫组化表达及临床病理特征分析:一项1971例的双中心研究OA

Objective To study the expression of HER2 in colorectal cancer(CRC)and its relationship with clinicopathological factors.Methods Clinicopathological data of colorectal cancer patients were collected.The ex-pressions of HER2,mismatch repair(MMR)proteins,and BRAF V600E protein were detected by immunohisto-chemital(IHC).HER2 gene amplification was detected by fluorescence in situ hybridization(FISH).Hotspot muta-tions of KRAS,NRAS,BRAF,and PIK3CA genes were detected by polymerase chain reaction(PCR),and microsat-ellite instability(MSI)was detected by fluorescence PCR-capillary electrophoresis.Chi-square(χ2)test or Fisher's exact test was used to evaluate the relationship between HER2 expression and clinicopathological factors,and the Mantel-Haenszel test was applied for ordinal variables.Results A total of 1 971 CRC cases were included in this study.The distribution of HER2 expression was as follows:0(58.0％),1+(34.9％),2+(5.6％),and 3+(1.5％).The overall positive rate of HER2 was 1.6％.HER2 3+was significantly associated with stage M1(distant metastasis)(P=0.036).The proportion of HER2 3+in patients with proficient mismatch repair(pMMR)(1.6％)was higher than that in patients with deficient mismatch repair(dMMR)(0),and the association was significant(P<0.001).There was no significant correlation between different HER2 expression levels and other clinicopathological factors,BRAF V600E protein expression,KRAS/NRAS/BRAF gene mutations,and MSI status(all P>0.05).Con-clusion HER2 overexpression(IHC 3+)is a feature associated with an increased risk of distant metastasis in CRC,and its expression correlates with left-sided/rectal tumor location and pMMR status.The HER2 expression pattern shows no significant correlation with other routine clinicopathological parameters or key mutations such as RAS/BRAF.