Colorectal Cancer K-ras Gene Mutation Test And Clinical Significance

BackgroundIn China, the incidence of colorectal cancer ranks the forth place of all Malignant neoplasms. With the progress of industrialization and changes in diet, the incidence of colorectal cancer showed a clear upward trend.K-ras gene mutation relates to the colorectal cancer closely in its genesis and development. The specific mechanisms are not yet entirely clear.As reported in the literature, K-ras gene mutation is an early event in colorectal cancer,playing an important role in the canceration of colorectal adenomas. The K-ras gene mutation rate of primary tumor tissue of colorectal cancer in the Western species is about 30% to 60%, race in the East for 17%～28%. K-ras gene mutation has no correlation with patient age, gender, tumor size and lymph node metastasis, but the relationship between the degree of differentiation and tumor stage is still in controversial.Molecular targeting therapy for cancer aims the link that may lead to cell cancer, such as cell signaling pathway, proto-oncogene and tumor suppressor genes, cytokines and their receptors, tumor blood vessel formation. The use of certain target molecules with specific binding of these antibodies, ligands, etc. can reverse the malignant behavior at the molecular level, inhibit tumor cell growth, even so dissipate. It is a new mode of biological treatment, which changes the treatment of cancer patients from general chemotherapy and (or) radiotherapy into a more effective and personalized treatment of low toxicity. Cetuximab is a chimeric monoclonal antibody which targets to the epidermal growth factor receptor (EGFR). As a commonly used drug, cetuximab has a clear effect. The research reports show that k-ras gene mutation can lead to colorectal cancer patients with primary resistance to cetuximab, and detection of k-ras gene mutation is the key guiding molecular targeted therapy.Currently, we can see no report about the relationship between neoadjuvant chemotherapy and k-ras gene mutations. ObjectiveIn this study,we test the K-ras gene of tissue from the Colorectal tumor,to explore the relationship between K-ras gene mutation and the clinical classification, newadjuvant chemotherapy.MethodsUsing pyrosequencing method for rapid detection of colorectal cancer K-ras gene organized by the Center 12 point mutation and 13 point mutation in codon. Collecting the postoperative pathologic examination results, clinical materials, newadjuvant chemotherapy data. Using SPSS statistical software, groups were analyzed usingχ2 test. Detection level for P≤0.05.Results(1)Colorectal cancer k-ras gene mutation rate is 26.41%,major at codon 12 (GGT→GAT, GGT→GTT) and codon 13 (GGC→AGC).We find no cocurrent mutation of codon 12.13.(2) K-ras gene mutation has no relationship with colorectal cancer by age, sex, tumor staging, tumor differentiation and lymph node metastasis.(3) K-ras gene mutation has no significant difference between neoadjuvant chemotherapy group and none neoadjuvant chemotherapy group.Conclusions(1) About a quarter of patients with colorectal cancer have k-ras gene mutation. We shoud detecte k-ras gene of Patients with colorectal cancer routinely, to guide comprehensive treatment in clinical better.(2) K-ras gene mutation has no relationship with colorectal cancer by clinicopathological features.(3) K-ras gene mutation has no significant difference between neoadjuvant chemotherapy group and none neoadjuvant chemotherapy group.