Iron in relation to gastric cancer in the Alpha-tocopherol, Beta-carotene Cancer Prevention Study.

Abstract

BACKGROUND:

Iron is an essential micronutrient that can have carcinogenic effects when at high or low concentrations. Previous studies of iron in relation to gastric cancer have not assessed subtype-specific relationships. We used the prospective Alpha-Tocopherol, Beta-Carotene (ATBC) Cancer Prevention Study to assess whether iron metrics were associated with gastric cardia cancer (GCC) and gastric noncardia cancer (GNCC).

METHODS:

We selected 341 incident gastric cancer cases (86 cardia, 172 noncardia, and 83 nonspecified), accrued during 22 years of follow-up, and 341 individually matched controls. We measured prediagnostic serum iron, ferritin, unsaturated iron binding capacity, and C-reactive protein. Total iron-binding capacity (TIBC) and transferrin saturation were estimated from these metrics. Dietary iron exposures were estimated from a food frequency questionnaire. Multivariable logistic regression was used for analysis.

RESULTS:

Serum iron metrics were not associated with GCC, except for a potential "n"-shaped relationship with TIBC (global P = 0.038). GNCC was inversely associated with serum ferritin (global P = 0.024), serum iron (global P = 0.060) and, possibly, transferrin saturation. TIBC appeared to share a "u"-shaped relationship with GNCC (global P = 0.033). Dietary iron exposures were not associated with either subsite. Adjustment for Helicobacter pylori and gastric atrophy had little effect on observed associations.

CONCLUSIONS:

We found little evidence for the involvement of iron exposure in the pathogenesis of GCC. GNCC was associated with an iron profile similar to that of iron deficiency.

IMPACT:

Our findings indicate that inverse associations between iron metrics and gastric cancer are driven by associations with GNCC. Further elucidation of potential mechanisms is warranted.

• Authors: Michael B Cook, Farin Kamangar, Stephanie J Weinstein, Demetrius Albanes, Jarmo Virtamo, Philip R Taylor, Christian C Abnet, Richard J Wood, Gayle Petty, Amanda J Cross, Sanford M Dawsey
• Journal: Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology (Cancer Epidemiol Biomarkers Prev) Vol. 21 Issue 11 Pg. 2033-42 (Nov 2012) ISSN: 1538-7755 [Electronic] United States
• PMID: 23001240 (Publication Type: Journal Article, Randomized Controlled Trial, Research Support, N.I.H., Intramural)
• Copyright: ©2012 AACR.

Chemical References

• Placebos
• Transferrin
• beta Carotene
• Ferritins
• Iron
• alpha-Tocopherol

Topics

• Aged
• Case-Control Studies
• Double-Blind Method
• Ferritins (blood)
• Finland (epidemiology)
• Humans
• Iron (blood)
• Male
• Middle Aged
• Placebos
• Risk Factors
• Stomach Neoplasms (blood, epidemiology, pathology, prevention & control)
• Transferrin (metabolism)
• alpha-Tocopherol (administration & dosage)
• beta Carotene (administration & dosage)