Supplementary Material for: Genetic Variants in One-Carbon Metabolism Pathway Predict Survival Outcomes of Early-Stage Non-Small Cell Lung Cancer

<b><i>Background:</i></b> This study was conducted to investigate the association between genetic variants in one-carbon metabolism and survival outcomes of surgically resected non-small cell lung cancer (NSCLC). <b><i>Methods:</i></b> We genotyped 41 potentially functional variants of 19 key genes in the one-carbon metabolism pathway among 750 NSCLC patients who underwent curative surgery. The association between genetic variants and overall survival (OS)/disease-free survival (DFS) were analyzed. <b><i>Results:</i></b> Among the 41 single-nucleotide polymorphisms (SNPs) analyzed, 4 SNPs (<i>MTHFD1L</i> rs6919680T&gt;G and rs3849794T&gt;C, <i>MTR</i> rs2853523C&gt;A, and <i>MTHFR</i> rs4846049G&gt;T) were significantly associated with survival outcomes. <i>MTHFD1L</i> rs6919680T&gt;G and <i>MTR</i> rs2853523C&gt;A were significantly associated with better OS (adjusted hazard ratio [aHR] = 0.73, 95% confidence interval [CI] = 0.54–0.99, <i>p</i> = 0.04) and worse OS (aHR = 2.14, 95% CI = 1.13–4.07, <i>p</i> = 0.02), respectively. <i>MTHFD1L</i> rs3849794T&gt;C and <i>MTHFR</i> rs4846049G&gt;T were significantly associated with worse DFS (aHR = 1.41, 95% CI = 1.08–1.83, <i>p</i> = 0.01; and aHR = 1.97, 95% CI = 1.10–3.53, <i>p</i> = 0.02, respectively). When the patients were divided according to histology, the associations were significant only in squamous cell carcinoma (SCC), but not in adenocarcinoma (AC). In SCC, <i>MTHFD1L</i> rs6919680T&gt;G and <i>MTR</i> rs2853523C&gt;A were significantly associated with better OS (aHR = 0.64, 95% CI = 0.41–1.00, <i>p</i> = 0.05) and worse OS (aHR = 2.77, 95% CI = 1.11–6.91, <i>p</i> = 0.03), respectively, and <i>MTHFD1L</i> rs3849794T&gt;C and <i>MTHFR</i> rs4846049G&gt;T were significantly associated with worse DFS (aHR = 1.73, 95% CI = 1.17–2.56, <i>p</i> = 0.01; and aHR = 2.78, 95% CI = 1.12–6.88, <i>p</i> = 0.03, respectively). <b><i>Conclusions:</i></b> Our results suggest that the genetic variants in the one-carbon metabolism pathway could be used as biomarkers for predicting the clinical outcomes of patients with early-stage NSCLC.

**背景**：本研究旨在探讨一碳代谢（one-carbon metabolism）相关基因变异与手术切除后非小细胞肺癌（non-small cell lung cancer, NSCLC）患者的生存结局之间的关联。
**方法**：本研究对750例接受根治性手术的NSCLC患者的一碳代谢通路中19个关键基因的41个潜在功能变异进行了基因分型，并分析了基因变异与总生存期（overall survival, OS）/无病生存期（disease-free survival, DFS）的关联。
**结果**：在分析的41个单核苷酸多态性（single-nucleotide polymorphism, SNPs）中，有4个SNPs（MTHFD1L rs6919680T>G、rs3849794T>C，MTR rs2853523C>A，以及MTHFR rs4846049G>T）与生存结局显著相关。其中，MTHFD1L rs6919680T>G与更好的总生存期相关（调整后风险比（adjusted hazard ratio, aHR）=0.73，95%置信区间（95% confidence interval, CI）=0.54~0.99，p=0.04），而MTR rs2853523C>A则与更差的总生存期相关（aHR=2.14，95%CI=1.13~4.07，p=0.02）。MTHFD1L rs3849794T>C与MTHFR rs4846049G>T则分别与更差的无病生存期相关（aHR=1.41，95%CI=1.08~1.83，p=0.01；aHR=1.97，95%CI=1.10~3.53，p=0.02）。按组织学类型对患者进行分组后，上述关联仅在鳞状细胞癌（squamous cell carcinoma, SCC）亚组中具有统计学意义，而在腺癌（adenocarcinoma, AC）亚组中无显著关联。在SCC亚组中，MTHFD1L rs6919680T>G与更好的总生存期相关（aHR=0.64，95%CI=0.41~1.00，p=0.05），MTR rs2853523C>A则与更差的总生存期相关（aHR=2.77，95%CI=1.11~6.91，p=0.03）；而MTHFD1L rs3849794T>C与MTHFR rs4846049G>T分别与更差的无病生存期相关（aHR=1.73，95%CI=1.17~2.56，p=0.01；aHR=2.78，95%CI=1.12~6.88，p=0.03）。
**结论**：本研究结果表明，一碳代谢通路相关基因变异可作为预测早期NSCLC患者临床结局的生物标志物。