Mutation status and prognostic values of KRAS, NRAS, BRAF and PIK3CA in 353 Chinese colorectal cancer patients

作者：Guo, Fang; Gong, Hai; Zhao, Huanhuan; Chen, Jing; Zhang, Yiming; Zhang, Lihua; Shi, Xin; Zhang, Aifeng; Jin, Hui; Zhang, Jianqiong^*; He, Youji^*

来源：Scientific Reports, 2018, 8(1): 6076.

DOI：10.1038/s41598-018-24306-1

• III COLON-CANCER
• STAGE-II
• V600E MUTATION
• POOR SURVIVAL
• RAS ONCOGENES
• RARE

Mutations in KRAS exon 2, BRAF and PIK3CA are commonly present in colorectal cancer (CRC) worldwide, but few data about RAS mutations outside KRAS exon 2 are available for Chinese CRCs. We, therefore, determined the mutation frequencies and prognostic values of KRAS exon 2, 3 and 4, NRAS exon 2 and 3, PIK3CA exon 9 and 20, and BRAF exon 15 by PCR and direct sequencing in 353 CRC patients from two Chinese clinical centers. KRAS exon 2, BRAF, PIK3CA mutations were identified in 42.2%, 4.5%, 12.3% of the cases, respectively. We found "rare mutations" in RAS genes in nearly 14% of CRCs-i.e., in almost a quarter (24.0%) of KRAS exon 2 wild type CRCs, including 2.3% in KRAS exon 3, 8.2% in KRAS exon 4 and 3.4% in NRAS. Stage I-III patients with PIK3CA or NRAS mutations developed more distant metastases (3-year risk in PIK3CA mutated and wild type patients: 23.3% vs 11.5%, P = 0.03; multivariate Hazard ratio (HR) = 3.129, P = 0.003; 3-year risk in NRAS mutated and wild type patients: 40.0% vs 12.2%, P = 0.012; multivariate HR = 5.152, P = 0.003). Our data emphasizes the importance of these novel molecular features in CRCs.

• 出版日期2018-4-17
• 单位东南大学