title: Folate intake and the risk of oral cavity and pharyngeal cancer: a pooled analysis within the International Head and Neck Cancer Epidemiology Consortium.
abstract: There are suggestions of an inverse association between folate intake and serum folate levels and the risk of oral cavity and pharyngeal cancers (OPCs), but most studies are limited in sample size, with only few reporting information on the source of dietary folate. Our study aims to investigate the association between folate intake and the risk of OPC within the International Head and Neck Cancer Epidemiology (INHANCE) Consortium. We analyzed pooled individual-level data from ten case-control studies participating in the INHANCE consortium, including 5,127 cases and 13,249 controls. Odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) were estimated for the associations between total folate intake (natural, fortification and supplementation) and natural folate only, and OPC risk. We found an inverse association between total folate intake and overall OPC risk (the adjusted OR for the highest vs. the lowest quintile was 0.65, 95% CI: 0.43-0.99), with a stronger association for oral cavity (OR = 0.57, 95% CI: 0.43-0.75). A similar inverse association, though somewhat weaker, was observed for folate intake from natural sources only in oral cavity cancer (OR = 0.64, 95% CI: 0.45-0.91). The highest OPC risk was observed in heavy alcohol drinkers with low folate intake as compared to never/light drinkers with high folate (OR = 4.05, 95% CI: 3.43-4.79); the attributable proportion (AP) owing to interaction was 11.1% (95% CI: 1.4-20.8%). Lastly, we reported an OR of 2.73 (95% CI:2.34-3.19) for those ever tobacco users with low folate intake, compared with nevere tobacco users and high folate intake (AP of interaction =10.6%, 95% CI: 0.41-20.8%). Our project of a large pool of case-control studies supports a protective effect of total folate intake on OPC risk.
authors: Department of Epidemiology, IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy.
authors: Carlotta
authors: C
authors: Galeone
authors: Valeria
authors: V
authors: Edefonti
authors: Maria
authors: M
authors: Parpinel
authors: Emanuele
authors: E
authors: Leoncini
authors: Keitaro
authors: K
authors: Matsuo
authors: Renato
authors: R
authors: Talamini
authors: Andrew F
authors: AF
authors: Olshan
authors: Jose P
authors: JP
authors: Zevallos
authors: Deborah M
authors: DM
authors: Winn
authors: Vijayvel
authors: V
authors: Jayaprakash
authors: Kirsten
authors: K
authors: Moysich
authors: Zuo-Feng
authors: ZF
authors: Zhang
authors: Hal
authors: H
authors: Morgenstern
authors: Fabio
authors: F
authors: Levi
authors: Cristina
authors: C
authors: Bosetti
authors: Karl
authors: K
authors: Kelsey
authors: Michael
authors: M
authors: McClean
authors: Stimson
authors: S
authors: Schantz
authors: Guo-Pei
authors: GP
authors: Yu
authors: Paolo
authors: P
authors: Boffetta
authors: Yuan-Chin Amy
authors: YC
authors: Lee
authors: Mia
authors: M
authors: Hashibe
authors: Carlo
authors: C
authors: La Vecchia
authors: Stefania
authors: S
authors: Boccia
mesh_terms: D000284:Administration, Oral; D016588:Anticarcinogenic Agents / Q000008:administration & dosage*; D016022:Case-Control Studies; D019587:Dietary Supplements; D005492:Folic Acid / Q000008:administration & dosage*; D006801:Humans; D009062:Mouth Neoplasms / Q000453:epidemiology / Q000517:prevention & control*; D010610:Pharyngeal Neoplasms / Q000453:epidemiology / Q000517:prevention & control*; D012306:Risk
chemical_list: D016588:Anticarcinogenic Agents; D005492:Folic Acid
keywords: diet; epidemiology; folate intake; oral cancer; risk factor