Folate status among patients with non-small cell lung cancer: A case-control study

Objective and Background: This case control study explored the purported inverse relationship between folate status and lung cancer development. Methods: Folate status of 46 postoperative non-small cell lung cancer (NSCLC) patients was compared to that of 44 non-cancer patients. Cancer patients had completed treatment > 3 months prior and had no evidence of cancer. Ineligibility criteria for all patients included (1) > 2 alcoholic drinks/day (2) ongoing tobacco use, or (3) folate supplementation > 400 μg/day. Results: No differences were found between groups in serum and RBC folate after adjustment for age and use of folate-interfering medications: geometric means (GM)×/geometric standard error (GSE): 7.9 ng/ml×/1.1 vs. 7.8 ng/ml×/1.1, respectively (P=0.91) for serum folate; 264 ng/ml×/1.1 vs. 263 ng/ml×/1.1, respectively (P=0.97) for RBC folate. Age- and creatinine-adjusted homocysteine was no different between groups: GM×/GSE: 9.4 μmol/L×/1.0 vs. 8.6 μmol/L×/1.0, respectively (P=0.17). No difference were seen in folate intake. Frequencies of the homozygous genotype for the MTHFR polymorphism, an enzyme important in folate metabolism and associated with a reduced risk of other cancers, were no different. Conclusions: This case control study does not support the hypothesis that low folate is an independent risk factor for NSCLC.