Toenail trace element status and risk of Barrett's oesophagus and oesophageal adenocarcinoma: results from the FINBAR study
A partir des données de l'étude "FINBAR" (417 cas et 221 témoins), cette étude évalue l'association entre des oligo-éléments (zinc, colbalt, sélénium) contenus dans les ongles et le risque d'endobrachyœsophage et d'adénocarcinome œsophagien
Trace elements have been cited as both inhibitory and causative agents of cancer but importantly exposure to them is potentially modifiable. This study aimed to examine toenail trace element status and risk of Barrett's oesophagus (BO) and oesophageal adenocarcinoma (OAC). Toenail clippings from each hallux were obtained from 638 participants of the FINBAR study (Factors Influencing the Barrett's Adenocarcinoma Relationship) comprising 221 healthy controls, 98 reflux oesophagitis, 182 BO and 137 OAC cases. The concentrations of eight toenail trace elements were determined using Instrumental Neutron Activation Analysis. Using multivariable adjusted logistic regression analysis, odds ratios (OR) and 95% CIs were calculated within tertiles of trace element concentrations. A two-fold increased risk of BO was observed, but not OAC, amongst individuals in the highest tertile of toenail zinc status OR 2.21 (95% CI 1.11-4.40). A higher toenail selenium status was not associated with risk of OAC OR 0.94 (95% CI 0.44-2.04) or BO OR 0.89 (95% CI 0.37-2.12). A borderline significant increased risk of BO was detected with a higher toenail cobalt concentration, OR 1.97 (95% CI 1.01-3.85). No association was found between toenail levels of chromium, cerium, mercury and OAC or BO risk. This is the first case-control study to investigate a variety of trace elements in relation to OAC and BO risk. Despite antioxidant and proapoptotic properties, no associations were found with selenium. Higher concentrations of toenail zinc and cobalt were associated with an increased BO risk, but not OAC. These findings need confirmation in prospective analysis. © 2012 Wiley-Liss, Inc.