Detection Of K-ras Gene Mutation And Efficacy Of Cetuximab Combined With Chemotherapy In Advanced Colorectal Cancer

Background and purpose:K-ras gene plays an important role in the progress of colorectal cancer.K-ras detection can be used for determining prognosis of colorectal cancer,especially for predicting the efficacy of Cetuximab treatment in advanced colorectal cancer.This study summarized the association among K-ras mutation,tumor characteristics and relapse rate after surgery,and also explored the efficacy of Cetuximab in the second/third-line treatment.Methods:Tissue samples of 27 colorectal cancer patients from Sir Run Run Shaw Hospital were analyzed to detect K-ras gene mutation by using Pyrosequencing method.10 of these patients were treated with Cetuximab combined with second/third-line chemotherapy,and were analyzed the relationship of K-ras gene and efficacy of Cetuximab plus chemotherapy.Results:There ware 17 wild-type and 10 mutated-type K-ras gene in all 27 cases with mutation rate of 37%.5 mutations occurred in codon12,and 5 in codon13.Mutations were not associated with clinical and pathologic characters,postoperation recurrent rate. Of the 10 cases who treated with Cetuximab,there were no complete response(CR),2 partial response(PR),5 stable disease(SD) and 3 progressive disease(PD).Of the 6 wild-type K-ras cases,there were no complete response(CR),2 partial response(PR),3 stable disease(SD) and 1 progressive disease(PD).Of the 4 mutated-type K-ras cases, there were no complete response(CR),no partial response(PR),2 stable disease(SD) and 2 progressive disease(PD).Conclusion:The mutation rate of the K-ras gene was similar with other reports.K-ras gene is an important biomarker for determining prognosis of colorectal cancer.