生物谷报道：在JAMA杂志最近一篇文章中，美国Fred Hutchinson癌症研究中心研究人员通过统计分析发现，几种肿瘤遗传易感性相关的候选基因多态性。
Dong教授等收集了2008年3月间，与肿瘤遗传易感性和基因多态性有关的161 meta分析研究报道，涉及到18种肿瘤、99个基因、344个突变类型，其中98个突变（28%）优势比（OR值）具有统计学意义，进一步行验前概率（0.001）和假阳性报道预测（FPRP<0.2）分析，有13个突变有显著意义。进一步提高标准后得到4个突变：谷胱苷肽S转移酶M1(GSTM1)空白基因型、NAT2快速乙酰化基因型与膀胱癌；亚甲基四氢叶酸还原酶(MTHFR)基因C677T突变型与胃癌；GSTM1空白基因型与白血病。
研究者发现，近三分之一的突变类型同肿瘤遗传易感性相关，其中很多编码代谢相关的酶类。
生物谷推荐原始出处：
CLINICIAN'S CORNER
Genetic Susceptibility to Cancer
The Role of Polymorphisms in Candidate Genes
Linda M. Dong, MPH, PhD; John D. Potter, MD, PhD; Emily White, PhD; Cornelia M. Ulrich, PhD; Lon R. Cardon, PhD; Ulrike Peters, PhD, MPH
JAMA. 2008;299(20):2423-2436.
Context Continuing advances in genotyping technologies and the inclusion of DNA collection in observational studies have resulted in an increasing number of genetic association studies.
Objective To evaluate the overall progress and contribution of candidate gene association studies to current understanding of the genetic susceptibility to cancer.
Data Sources We systematically examined the results of meta-analyses and pooled analyses for genetic polymorphisms and cancer risk published through March 2008.
Study Selection We identified 161 meta-analyses and pooled analyses, encompassing 18 cancer sites and 99 genes. Analyses had to meet the following criteria: include at least 500 cases, have cancer risk as outcome, not be focused on HLA antigen genetic markers, and be published in English.
Data Extraction Information on cancer site, gene name, variant, point estimate and 95% confidence interval (CI), allelic frequency, number of studies and cases, tests of study heterogeneity, and publication bias were extracted by 1 investigator and reviewed by other investigators.
Results These 161 analyses evaluated 344 gene-variant cancer associations and included on average 7.3 studies and 3551 cases (range, 508-19 729 cases) per investigated association. The summary odds ratio (OR) for 98 (28%) statistically significant associations (P value <.05) were further evaluated by estimating the false-positive report probability (FPRP) at a given prior probability and statistical power. At a prior probability level of 0.001 and statistical power to detect an OR of 1.5, 13 gene-variant cancer associations remained noteworthy (FPRP <0.2). Assuming a very low prior probability of 0.000001, similar to a probability assumed for a randomly selected single-nucleotide polymorphism in a genome-wide association study, and statistical power to detect an OR of 1.5, 4 associations were considered noteworthy as denoted by an FPRP value <0.2: GSTM1 null and bladder cancer (OR, 1.5; 95% CI, 1.3-1.6; P = 1.9 x 10–14), NAT2 slow acetylator and bladder cancer (OR, 1.46; 95% CI, 1.26-1.68; P = 2.5 x 10–7), MTHFR C677T and gastric cancer (OR, 1.52; 95% CI, 1.31-1.77; P = 4.9 x 10–8), and GSTM1 null and acute leukemia (OR, 1.20; 95% CI, 1.14-1.25; P = 8.6 x 10–15). When the OR used to determine statistical power was lowered to 1.2, 2 of the 4 noteworthy associations remained so: GSTM1 null with bladder cancer and acute leukemia.
Conclusion In this review of candidate gene association studies, nearly one-third of gene-variant cancer associations were statistically significant, with variants in genes encoding for metabolizing enzymes among the most consistent and highly significant associations.
Author Affiliations: Fred Hutchinson Cancer Research Center, Seattle, Washington (Drs Dong, Potter, White, Ulrich, Cardon, and Peters) and Departments of Epidemiology (Drs Dong, Potter, White, Ulrich, and Peters) and Biostatistics (Dr Cardon), University of Washington, Seattle.
