Folate, vitamin B₆, vitamin B₁₂ and methionine intakes and risk for nasopharyngeal carcinoma in Chinese adults: a matched case–control study

Abstract

Many studies have suggested that folate-related one-carbon metabolism-related nutrients may play a role in certain cancer risks, but few studies have assessed their associations with the risk for nasopharyngeal carcinoma (NPC). In this study, we investigated the association between four folate-related one-carbon metabolism-related nutrients (folate, vitamin B 6 , vitamin B 12 and methionine) and NPC risk in Chinese adults. A total of 600 patients newly diagnosed (within 3 months) with NPC were individually matched with 600 hospital-based controls by age, sex and household type (urban v. rural). Folate, vitamin B 6 , vitamin B 12 and methionine intakes were measured using a validated seventy-eight-item FFQ. A higher dietary folate or vitamin B 6 intake was associated with a lower NPC risk after adjusting for potential confounders. The adjusted OR of NPC for quartiles 2-4 (v. 1) were 0·66 (95 % CI 0·48, 0·91), 0·52 (95 % CI 0·37, 0·74) and 0·34 (95 % CI 0·23, 0·50) (P trend < 0·001) for folate and 0·72 (95 % CI 0·52, 1·00), 0·55 (95 % CI 0·39, 0·78) and 0·44 (95 % CI 0·30, 0·63) (P trend < 0·001) for vitamin B 6 . No significant association with NPC risk was observed for dietary vitamin B 12 or methionine intake. The risk for NPC with dietary folate intake was more evident in the participants who were not exposed to toxic substances than in those who were exposed (P interaction = 0·014). This study suggests that dietary folate and vitamin B 6 may be protective for NPC in a high-risk population.

Folic acid inhibits nasopharyngeal cancer cell proliferation and invasion via activation of FRα/ERK1/2/TSLC1 pathway

“…Folic acid (FA), a fully oxidized monoglutamyl form of folate, is frequently used as nutritional supplement for folate, since it is more stable and its bioavailability as compared with folate [ 7 ]. It is reported that dietary FA intake is protective for NPC in a high-risk population of Chinese adults [ 8 ]. Folate receptor α (FRα), a single chain glycosyl-phosphatidylinositol-anchored membrane protein, is the major transporter of FA and acts as an important mediator in many cancers [ 9 ].…”

Association between folate intake and risk of head and neck squamous cell carcinoma

“…The included main studies were conducted in Europe (n = 5), [ 18 , 21 , 28 – 30 ] and others were conducted in Asia (n = 2), [ 20 , 31 ] North America (n = 1), [ 19 ] and South America (n = 1). [ 32 ] Among the 9 included studies, 3 studies involved patients with comprehensive HNSCC, [ 19 – 21 ] 3 studies involved patients with laryngeal cancer, [ 18 , 29 , 32 ] 2 studies involved patients with nasopharyngeal carcinoma, [ 30 , 31 ] and 1 study involved patients with oral cavity and pharyngeal squamous cell carcinoma (OPSCC). [ 28 ] Seven studies investigated the associations between dietary folate intake and HNSCC risk.…”

“…[ 19 , 21 ] In terms of source of control, 7 studies were hospital-based [ 18 , 28 – 32 ] and 2 studies were population-based. [ 19 , 21 ] Five studies matched high score with NOS scale, [ 18 – 21 , 31 ] and 4 studies matched low score. [ 28 – 30 , 32 ] Four studies were included in dose–response analysis.…”

“…[ 28 – 30 , 32 ] Four studies were included in dose–response analysis. [ 20 , 29 , 31 , 32 ] The main profiles of the included 9 studies are summarized in Table 1 .…”

The Role of Genetic Polymorphisms as Related to One-Carbon Metabolism, Vitamin B6, and Gene–Nutrient Interactions in Maintaining Genomic Stability and Cell Viability in Chinese Breast Cancer Patients

“…Folate, vitamin B6 (B6), and vitamin B12 (B12) have been proven to play important roles in the one-carbon metabolism pathway and the prevention of carcinogenesis: (a) in the transformation of homocysteine (Hcy) to methionine for methylation of DNA to ensure gene expression and genomic stability; and (b) in the synthesis of purine precursors and thymidylate of nucleic acid (DNA and RNA) [ 1 , 2 , 3 , 4 ]. B6 is not only a crucial coenzyme for serine hydroxymethyltransferase (SHMT) in the reversible transformation of serine and tetrahydrofolate (THF) to 5,10-methylene THF and glycine [ 5 , 6 ], a reaction that offers one-carbon units for S-adenosylmethionine (SAM), and for the synthesis of purine and pyrimidine, but it is also a cofactor for cystathionine β-synthase (CBS), which is involved in the transsulfuration pathway where Hcy is converted into cystathionine.…”