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document
Iron in relation to gastric cancer in the Alpha-tocopherol , Beta-carotene Cancer Prevention Study . 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 .
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Intervention_Pharmacological
Iron
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Intervention_Pharmacological
Iron
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Intervention_Pharmacological
Dietary iron
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Intervention_Pharmacological
iron
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Intervention_Pharmacological
iron
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Intervention_Pharmacological
iron
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Outcome_Adverse-effects
carcinogenic effects
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Outcome_Physical
gastric cardia cancer ( GCC )
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Outcome_Physical
gastric noncardia cancer
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Outcome_Adverse-effects
( GNCC )
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Outcome_Physical
Total iron-binding capacity ( TIBC )
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Outcome_Physical
Serum iron metrics
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Outcome_Physical
GCC
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Outcome_Physical
GNCC
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Outcome_Physical
serum ferritin
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Outcome_Physical
serum iron
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Outcome_Physical
transferrin saturation
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Outcome_Physical
TIBC
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Outcome_Physical
GNCC
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Outcome_Physical
Dietary iron exposures
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Outcome_Physical
GCC
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Outcome_Physical
GNCC
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Participant_Condition
gastric cancer
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Participant_Condition
gastric cardia cancer
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Participant_Condition
GCC
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Participant_Condition
gastric noncardia cancer
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Participant_Condition
GNCC
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Participant_Sample-size
341
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Participant_Condition
gastric cancer
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Participant_Sample-size
86
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Participant_Condition
cardia
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Participant_Sample-size
172
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Participant_Condition
noncardia
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Participant_Sample-size
83
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Participant_Condition
GNCC