Dan Lydia A, Werdyani Salem, Xu Jingxiong, Shestopaloff Konstantin, Hyde Angela, Dicks Elizabeth, Younghusband Ban, Green Jane, Parfrey Patrick, Xu Wei, Savas Sevtap
Discipline of Genetics, Faculty of Medicine, Memorial University, St. John's, Newfoundland, Canada.
Department of Biostatistics, Princess Margaret Hospital, University of Toronto, Toronto, Ontario, Canada.
Cancer Med. 2016 Sep;5(9):2221-31. doi: 10.1002/cam4.796. Epub 2016 Jun 23.
In this study, we aimed to investigate the associations of genetic variations within select genes functioning in angiogenesis, lymph-angiogenesis, and metastasis pathways and the risk of outcome in colorectal cancer patients. We followed a two-stage analysis: First, 381 polymorphisms from 30 genes (eight Vascular Endothelial Growth Factor (VEGF) and 22 Matrix Metalloproteinase [MMP] genes) were investigated in the discovery cohort (n = 505). Then, 16 polymorphisms with the lowest P-value in this analysis were investigated in a separate replication cohort (n = 247). Genotypes were obtained using the Illumina(®) HumanOmni-1-Quad (discovery cohort) and Sequenom MassArray(®) (replication cohort) platforms. The primary outcome measure was overall survival (OS). Kaplan-Meier, univariate and multivariable Cox regression methods were used to test the associations between genotypes and OS. Four SNPs (rs12365082, rs11225389, rs11225388, and rs2846707) had the univariate analysis P < 0.05 in both the discovery and replication cohorts. These SNPs are in linkage disequilibrium with each other to varying extent and are located in the MMP8 and MMP27 genes. In the multivariable analysis adjusting for age, stage, and microsatellite instability status, three of these SNPs (rs12365082, rs11225389, rs11225388) were independent predictors of OS (P < 0.05) in the discovery cohort. However, the same analysis in the replication cohort did not yield statistically significant results. Overall, while the genetic variations in the VEGF and MMP genes are attractive candidates as prognostic markers, our study showed no evidence of associations of a large set of SNPs in these genes and overall survival of colorectal cancer patients in our study.
在本研究中,我们旨在调查在血管生成、淋巴管生成和转移途径中起作用的特定基因内的遗传变异与结直肠癌患者预后风险之间的关联。我们采用两阶段分析:首先,在发现队列(n = 505)中研究了来自30个基因(8个血管内皮生长因子(VEGF)基因和22个基质金属蛋白酶(MMP)基因)的381个多态性。然后,在一个单独的验证队列(n = 247)中研究了该分析中P值最低的16个多态性。使用Illumina(®)HumanOmni-1-Quad平台(发现队列)和Sequenom MassArray(®)平台(验证队列)获得基因型。主要结局指标为总生存期(OS)。采用Kaplan-Meier法、单变量和多变量Cox回归方法来检验基因型与OS之间的关联。在发现队列和验证队列中,四个单核苷酸多态性(rs12365082、rs11225389、rs11225388和rs2846707)的单变量分析P < 0.05。这些单核苷酸多态性在不同程度上彼此处于连锁不平衡状态,且位于MMP8和MMP27基因中。在对年龄、分期和微卫星不稳定性状态进行校正的多变量分析中,其中三个单核苷酸多态性(rs12365082、rs11225389、rs11225388)在发现队列中是OS的独立预测因子(P < 0.05)。然而,在验证队列中的相同分析未得出具有统计学意义的结果。总体而言,虽然VEGF和MMP基因中的遗传变异作为预后标志物很有吸引力,但我们的研究表明,在我们的研究中,这些基因中的大量单核苷酸多态性与结直肠癌患者的总生存期之间没有关联证据。