Supplementary Material for: Colorectal Cancer with BRAF D594G Mutation Is Not Associated with Microsatellite Instability or Poor Prognosis

Objective:BRAF D594G mutations in colorectal cancer patients are not clearly understood. We retrospectively investigated the clinicopathological features of colorectal cancers with BRAF D594G mutations. Methods: We selected 908 colorectal cancer patients who underwent surgical resection from January 2008 to January 2013, and assessed BRAF, KRAS, microsatellite instability, and CpG island methylator phenotype (CIMP). Results: We detected BRAF D594G in 7 patients and BRAF V600E in 45 patients. The clinicopathological features of cancers with BRAF D594G mutation were similar to those with BRAF wild-type, but differed from those with BRAF V600E mutations. Regarding microsatellite instability status, 44.4% of cases with BRAFV600E mutations exhibited high microsatellite instability, compared to 14.3% of those with BRAF D594G mutations and 4.4% of those with BRAF wild-type. There were no CIMP-positive tumors in cancers with BRAF D594G mutations, whereas 67.8% of tumors with BRAF V600E mutations were CIMP-positive. In stage IV cancers, the survival rates of patients at 2 years were 8.5, 50.0, and 68.2% in the BRAF V600E mutation, BRAF D594G mutation, and BRAF wild-type groups, respectively.Conclusion: Colorectal cancers with BRAF D594G mutations exhibit similar clinicopathological features, microsatellite instability status, and prognosis as those with BRAF wild-type.研究目的：结直肠癌患者的BRAF D594G突变尚未得到明确阐明。本研究回顾性分析携带BRAF D594G突变的结直肠癌的临床病理特征。 方法：本研究选取2008年1月至2013年1月间接受手术切除的908例结直肠癌患者，对BRAF、KRAS、微卫星不稳定性（microsatellite instability）及CpG岛甲基化表型（CpG island methylator phenotype, CIMP）进行检测与评估。 结果：本研究共检出7例BRAF D594G突变病例与45例BRAF V600E突变病例。BRAF D594G突变型结直肠癌的临床病理特征与BRAF野生型结直肠癌相似，但与BRAF V600E突变型结直肠癌存在显著差异。在微卫星不稳定性状态方面，BRAF V600E突变组中有44.4%的病例表现为高微卫星不稳定性，而BRAF D594G突变组与BRAF野生型组的对应比例分别为14.3%与4.4%。BRAF D594G突变组未检测到CIMP阳性肿瘤，而BRAF V600E突变组中有67.8%的肿瘤为CIMP阳性。在Ⅳ期结直肠癌患者中，BRAF V600E突变组、BRAF D594G突变组及BRAF野生型组的2年生存率分别为8.5%、50.0%与68.2%。 结论：携带BRAF D594G突变的结直肠癌，其临床病理特征、微卫星不稳定性状态及预后与BRAF野生型结直肠癌相似。