Plasma Folate, Vitamin B12, and Homocysteine and Cancers of the Esophagus, Stomach, and Liver in a Chinese Population

Abstract

Evidence is accumulating regarding a role of micronutrients in folate metabolism in cancer risk. We investigated the associations of plasma folate, vitamin B12, and homocysteine with upper gastrointestinal (GI) cancers in a population-based case-control study in Taixing City, China. With informed consent, we recruited cases with cancers of esophagus (n = 218), stomach (n = 206), and liver (n = 204), and one common healthy control group (n = 405). A standardized epidemiologic questionnaire was used in face-to-face interviews, and blood samples were collected during interviews. We observed an inverse association between plasma folate levels and liver cancer. The adjusted odds ratio (aOR) was 0.46 [95% confidence interval (CI) = 0.24–0.88] comparing individuals in the highest quartile to those in the lowest. We found a positive association between plasma vitamin B12 levels and all three cancers. The aORs for those in the highest quartile were 2.80 (95% CI = 1.51–5.18) for esophageal cancer, 2.17 (1.21–3.89) for stomach cancer, and 9.97 (4.82–20.60) for liver cancer, comparing to those in the lowest quartile. We further observed interaction between plasma folate and vitamin B12 on these cancers. Our data indicated associations between plasma folate and vitamin B12 with upper GI cancers in Chinese population. Further research is warranted considering the debate over the necessity of food fortification.

ACKNOWLEDGMENTS

The authors would like to acknowledge Dr. Regina Santella (Columbia University) for her assistance in measuring plasma AFB1-albumin adducts. The authors would also like to thank all personnel in Drs. David Heber's and Zuo-Feng Zhang's labs for their generous assistance with this project.

Funding

This work is supported in part by the International Union Against Cancer (UICC) Technology Transfer fellowship (ICRETT) awarded to Dr. Li-Na Mu and by the Foundation for the Author of National Excellent Doctoral Dissertation of P.R. China, No. 200157, awarded to Dr. Lin Cai. This study was also partially supported by the NIH National Institute of Environmental Health Sciences, National Cancer Institute, Department of Health and Human Services (grant numbers ES06718, ES 011667, and CA09142), as well as the Alper Research Program of Environmental Genomics of UCLA Jonsson Comprehensive Cancer Center and the UCLA Clinical Nutrition Research Unit.