Breast cancer is associated with systemic metabolic and inflammatory alterations that may
influence tumor progression and host physiology. However, the relationship between iron
metabolism, redox balance, inflammation, and structural cellular markers in patients remains
incompletely understood. Here, we investigated the interaction between systemic iron
parameters, oxidative stress markers, inflammation, body composition, and dietary intake in
women with breast cancer compared with healthy controls. In this cross-sectional study including
40 women (23 with breast cancer and 17 controls), patients with cancer exhibited a significantly
lower phase angle, higher concentrations of high-sensitivity C-reactive protein, and reduced
levels of nitrite and myeloperoxidase activity. Circulating markers of iron metabolism did not
differ significantly between groups. Energy and macronutrient intake were similar after dietary
calibration, although dietary iron intake was lower in the cancer group. Correlation analyses
revealed positive associations between ferritin and superoxide dismutase activity in patients and
between ferritin and ceruloplasmin in controls. These findings suggest that systemic
inflammatory and redox alterations occur in breast cancer despite apparently stable circulating
iron levels, highlighting a potential role for iron–redox interactions in the metabolic remodeling
associated with the disease.