In conclusion, this meta-analysis indicated that <i>MTRR</i> rs1801394</span> was significantly associated with LC in smokers, and <i>MTHFR</i> rs1801133 polymorphisms was also significantly associated with LC in smokers and East Asians.
In addition, we found interactions between the MTRR A66G polymorphism and smoking (P = 0.015) and the MTHFR A1,298C polymorphism and alcohol consumption (P = 0.025) for risk of lung cancer overall.
In conclusion, our data provide evidence supporting the association between the MTR 2756A>G and MTRR 66A>G polymorphisms and lung cancer risk, which may be modulated by dietary nutrient intake.