Table 4.

Summary of the main association between iron (diet and biomarkers) and different cancer types

Dietary ironHeme iron intakeBiomarkers of iron overloada
TumorCase–controlProspectiveCase–controlProspectiveCase–controlProspective
Colorectal2b (2b)8b (1) [2]7 (2)4 [3]
Breast43 (1)3
Gastric3 [1]112 (1)1
EAC2 [1]2 (2)21 [1]
Lung1 (1)3 (2)
Endometrial2 (1)2 (1)
Bladder1
Pancreatic11
Prostate1
Oral1c

NOTE: n (n) [n]: n = number of studies, (n) = studies with a statistically significant positive association between exposure and cancer risk, [n] = studies with a statistically significant negative association between exposure and cancer risk.

  • aBiomarkers of iron overload refer to high levels of serum ferritin, transferrin saturation, toenail iron, and low levels of TIBC.

  • bIncludes 1 case–control study and 3 prospective studies with total iron intake (with supplements).

  • cSerum ferritin statistically significant positive association with cancer risk and serum iron and transferrin saturation statistically significant negative association with cancer risk.