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World J Gastroenterol. Feb 14, 2011; 17(6): 809-816
Published online Feb 14, 2011. doi: 10.3748/wjg.v17.i6.809
Clinical significance of K-ras and BRAF mutations in Chinese colorectal cancer patients
Hong Shen, Ying Yuan, Han-Guang Hu, Xiao-Xian Ye, Mo-Dan Li, Department of Oncology, Second Affiliated Hospital, Zhejiang University College of Medicine, Hangzhou 310009, Zhejiang Province, China
Xian Zhong, Department of Internal Medicine, Bin Jiang Hospital, Hangzhou 310052, Zhejiang Province, China
Wei-Jia Fang, Department of Medical Oncology, First Affiliated Hospital, Zhejiang University College of Medicine, Hangzhou 310003, Zhejiang Province, China
Shu Zheng, Key Laboratory of Cancer Prevention and Intervention of Ministry of Education, Cancer Institute, Second Affiliated Hospital, Zhejiang University College of Medicine, Hangzhou 310009, Zhejiang Province, China
Author contributions: Shen H supervised the study, acquired and analyzed the data, and drafted the manuscript; Yuan Y co-supervised the field activities and designed the analysis strategy; Hu HG and Zhong X reviewed and edited the manuscript; Ye XX, Li MD and Fang WJ interpreted the data; Zheng S designed the study, co-supervised the field activities, and revised manuscript critically for important intellectual content.
Supported by The Department of Education of Zhejiang Province of China, grant No. Y200804314; the Zhejiang Provincial Natural Science Foundation, grant No. R2090353; the Department of Science and Technology of Zhejiang Province, grant No. 2008C33039; and the Chinese Ministry of Health, grant No. N20100148
Correspondence to: Shu Zheng, Professor, Key Laboratory of Cancer Prevention and Intervention of Ministry of Education, Cancer Institute, Second Affiliated Hospital, Zhejiang University College of Medicine, 88 Jiefang Road, Hangzhou 310009, China. firstname.lastname@example.org
Telephone: +86-571-87784501 Fax: +86-571-87214404
Received: November 25, 2010
Revised: January 4, 2011
Accepted: January 11, 2011
Published online: February 14, 2011
AIM: To identify and assess mutations in the K-ras and BRAF genes in a cohort of Chinese patients with colorectal cancer (CRC) for their association with various clinicopathological parameters and prognosis.
METHODS: Genomic DNA was isolated from frozen tissues. Pyrosequencing analysis was conducted to detect mutations in the K-ras (codons 12, 13, and 61) and BRAF genes (codon 600). Statistical analysis was carried out using SPSS-15.0 software.
RESULTS: Among the 118 colorectal cancer patients, we detected 41 (34.7%) mutations in the K-ras gene. Mutation frequencies at codon 12 and codon 13 were 23.7% (28/118) and 10.2% (12/118), respectively. Only one patient harbored a point mutation at codon 61 (0.8%, 1/118). Gender was the only factor that showed an obvious relationship with K-ras gene mutation (female 44.7% vs male 28.2%, P = 0.037). Other clinicopathological features, such as age, location of the tumor, tumor differentiation, Tumor, Node and Metastases classification, and the Union for International Cancer Control staging, showed no positive relationship with K-ras gene mutations. No significant correlation was observed between the presence of K-ras mutations (codons 12, 13, and 61) and the survival of the patients. BRAF mutations were rare, and only two patients (1.7%) harbored a detectable mutation at codon 600.
CONCLUSION: K-ras gene mutation is a common event in our 118 Chinese CRC patients, with an obvious relationship with gender. However, it seems not to be an independent prognostic factor in CRC patients. The BRAF gene is rarely mutated in Chinese CRC patients.