Associations Between Serum Iron Biomarkers and Breast Cancer Tumor Size.

Using a large sample of women from a U.S. prospective cohort, we assessed associations between several serum iron measures at baseline and breast cancer tumor size and metastatic status. All estimated associations were close to zero with no evidence to support our hypothesis of higher body iron levels associated with larger tumor size. These results suggest the human tumor microenvironment operates independently of circulating serum iron levels.