Abstract 4654: Supplemental one-carbon metabolism related B vitamins and lung cancer risk in the Women's Health Initiative

We and others have reported associations between B vitamins principally involved in one-carbon metabolism and increased lung cancer risk; however results for women have been inconsistent. Here we report on the association of supplemental vitamins B6, folic acid, and B12 intake and lung cancer risk using data from the Women's Health Initiative (WHI) study of postmenopausal women. Between 1993 and 1998, 161,808 women were recruited to participate in the WHI at 40 US clinical centers. After exclusions, 159,232 women were available for analysis and followed prospectively for 18.3 years. Among them, 3,836 incident lung cancer cases were diagnosed. At baseline, supplemental B vitamins from multivitamins, vitamin mixtures, and individual supplements were assessed. Adjusted Cox regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for associations between supplemental B vitamin intake and lung cancer risk. Relative to non-users, women who took ≥50 mg/d of vitamin B6 had 18% (HR 0.82, 95% CI: 0.70-0.97) reduced lung cancer risk. Associations did not differ significantly by smoking status or lung cancer histology. Intakes of folic acid and vitamin B12 were not associated with risk. There is a need for replication of our findings from large, prospective studies with high-quality measurement of supplement intakes. As such, no recommendation can be made at present on the use of B6 supplements for lung cancer prevention in women. Citation Format: Theodore M. Brasky, Roberta M. Ray, Sandi L. Navarro, Jeannette M. Schenk, Alison M. Newton, Marian L. Neuhouser. Supplemental one-carbon metabolism related B vitamins and lung cancer risk in the Women's Health Initiative [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4654.