Study On The Correlation Between Egfr Gene Mutation In Gastric Carcinoma

Objective:To detect expression of epidermal growth factor receptor(EGFR)and epidermal growth factor receptor variant III(EGFRvIII) protein and mutations of EGFR gene in gastric carcinoma(GC), to characterize the important role of EGFR mutation to expression the protein, clinicopathological parameters and biological behavior in GC.Methods:(1) EGFR and EGFRvIII protein expression in 105 cases of GC by immunohistochemistry (SP) (2)Polymerase chain reaction-single strand conformation polymorphism analysis (PCR-SSCP) method and DNA sequencing technology, expansion of 105 cases of GC EGFR gene exons 18-21, based on conformational change of its gene mutation detection.(3)The relationship between EGFR and EGFRvIII protein expression, EGFR mutations, clinicopathological parameters and biological behavior was analyzed by Fisher s exact test andχ2 test in 105 cases of GC.Results:(1) EGFR and EGFRvIII protein expression in 105 cases of GC:the rate of EGFR and EGFRvIII protein expression was 46.67% and 35.24%, Their expression were unrelated with gender and age of gastric carcinoma(P>0.05), but were closely related with the degree of differentiation, depth of invasion, lymph node metastasis and clinical stages(P<0.05) and their expression was correlation(P<0.01). (2)105 cases of gastric carcinoma in two cases of detected mutations:there were 3 cases were detected of 105 cases, the rate of mutation was 2.86%; which of two cases in exon 19 were 2234-2249 TGGAATTAAGAGAAGC deletion mutation; one case in exon 21 was nucleotide 2573 point mutation(2573T→G), mutant protein structure so that arginine mutation of leucine (L858R). (3) EGFR protein expression and gene mutation analysis showed:one case associated with EGFR protein positive expression, while the other one was not of two cases of exon 19 in mutations; one case of exon 21 in mutation was associated with EGFR protein positive expression, which had no correlation (P> 0.05). (4) EGFR gene mutations and clinicopathological parameters analysis that:one case was differentiated adenocarcinoma for progress, accompanied by lymph node metastasis, the other was mucinous adenocarcinoma for progress, accompanied by lymph node metastasis of exon 19 in mutations; the case of exon 21 in mutation was advanced case of poorly differentiated adenocarcinoma, accompanied by lymph node metastasis. EGFR gene mutations were unrelated with gender, age, degree of differentiation and clinical stage (P> 0.05), but were related with the depth of invasion and lymph node metastasis correlation (P<0.05).Conclusion:(1) EGFR and EGFRv III is highly expressed in gastric cancer, gastric cancer occurrence and development may play a major role; its expression with age, gender, no correlation with the degree of differentiation, depth of invasion, lymph node metastasis and clinical staging could be used as to determine prognosis of gastric cancer indicators.(2) Expression of EGFR and EGFRvIII had positive correlation, overexpression of EGFR in gastric carcinoma may be associated with the EGFR variantⅢ. (3) EGFR gene mutations in gastric carcinoma organizations were not frequent events may be the occurrence and development of GC can not afford a major role; the cases of EGFR gene mutations in gastric carcinoma may be had stronger ability of invasion and metastasis. (4) Expression of EGFR protein was unrelated with EGFR gene exon 18,19,20,21 mutations, which was not a main mechanism in overexpression of EGFR protein.