Abstract 2273: Serum choline, methionine, betaine, dimethylglycine, and trimethylamine-N-oxide in relation to pancreatic cancer risk in two nested case-control studies in Asian populations

Abstract

Abstract Background: Choline, methionine, and betaine are methyl group donors associated with DNA methylation. Diets deficient in choline and methionine have been shown to promote pancreatic carcinogenesis in experimental animals. We have previously reported an inverse association between dietary intake of choline and pancreatic cancer risk in a prospective cohort of Singapore Chinese. In the present study biomarkers of dietary choline and other methyl donor nutrients were evaluated in relation to pancreatic cancer risk. Method: Two case-control studies were nested within the Shanghai Cohort Study (129 cases and 258 matched controls) and the Singapore Chinese Health Study (58 cases and 104 matched controls). Concentrations of choline, methionine, betaine, dimethylglycine (DMG), and trimethylamine-N-oxide (TMAO) were measured by LC-MS/MS in pre-diagnostic serum samples. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using conditional logistic regression method with adjustment for potential confounders. Results: Choline, methionine, and betaine were moderately associated with each other (spearman correlation coefficient: 0.28 ~0.43). In the pooled analysis, serum choline, betaine, and methionine were inversely associated with risk of pancreatic cancer, while TMAO, an oxidative metabolite of choline produced by gut microbiota, was positively associated with risk of pancreatic cancer. Compared with the lowest quartile, ORs (95%CIs) of pancreatic cancer for the highest quartiles of choline, methionine, betaine, and TMAO were 0.37 (0.17-0.80), 0.39 (0.22-0.69), 0.49 (0.28-0.85), and 1.60 (0.94-2.74), respectively (all Ps for trend < 0.05). DMG was not associated with pancreatic cancer risk. Conclusion: The novel inverse associations of serum choline, methionine, and betaine with risk of pancreatic cancer support the notion that methyl groups related to DNA methylation may modulate the risk of pancreatic cancer development. The positive association between TMAO and pancreatic cancer risk suggested gut microbiota may play an important role in pancreatic carcinogenesis. Citation Format: Joyce Huang, Lesley Butler, Øivind Midttun, Renwei Wang, Aizhen Jin, Yu-Tang Gao, Per Ueland, Woon-Puay Koh, Jian-Min Yuan. Serum choline, methionine, betaine, dimethylglycine, and trimethylamine-N-oxide in relation to pancreatic cancer risk in two nested case-control studies in Asian populations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2273. doi:10.1158/1538-7445.AM2017-2273