Disruption of Elemental Homeostasis and Oxidative Balance in Breast Cancer Patients: The Role of Heavy Metals and Trace Elements.

Breast cancer is the most frequently diagnosed malignancy among women globally, accounting for approximately 2.3 million new cases and 670,000 deaths in 2022. Trace element imbalance, heavy metal exposure, and oxidative stress play critical roles in the pathogenesis of breast cancer (BC). This study aimed to determine the serum concentrations of total sulfhydryl (TSH) groups-a marker of non-enzymatic antioxidant capacity distinct from thyroid-stimulating hormone-ischemia-modified albumin (IMA), essential trace elements (Zn, Mg, Cu, Mn, Fe), and toxic heavy metals (Cd, Pb) in newly diagnosed BC patients before initiating chemotherapy, and to compare these parameters with healthy individuals. The study was conducted at Van Yüzüncü Yıl University Dursun Odabaş Medical Center and included 30 newly diagnosed BC patients and 30 healthy volunteers. Blood samples were collected into trace element-grade anticoagulant-free serum tubes. Serum levels of trace elements and heavy metals were analyzed using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES, Thermo Scientific iCAP 6900). TSH levels were measured using the DTNB (Ellman) method, and IMA levels were assessed colorimetrically. Statistical analyses were performed using SPSS 19.0; normality was assessed by the Shapiro-Wilk test; group comparisons employed the Mann-Whitney U test, with a significance level set at p < 0.05. The results demonstrated that serum concentrations of Cu, Fe, Mg, Mn, and Zn were significantly lower in the patient group compared to controls (p < 0.001). Conversely, levels of Cd and Pb were significantly higher in BC patients (p < 0.001). IMA levels were significantly increased (44.71 ± 4.03 vs. 22.52 ± 0.27 ABSU; p < 0.001), while TSH levels were significantly decreased (1.58 ± 0.45 vs. 3.26 ± 0.05 mmol/L; p < 0.001). Spearman correlation analysis identified a significant positive association between serum Zn and IMA within the patient group (r = 0.493, p = 0.007). These findings indicate that breast cancer is associated with disrupted mineral homeostasis, increased toxic metal accumulation, and impaired antioxidant defense, leading to oxidative stress. However, the cross-sectional design limits causal inference; these results represent associations that require validation in larger, prospective cohorts. The combined evaluation of trace elements, IMA, and TSH may serve as potential supportive biomarkers in breast cancer.