Altered trace and toxic element profiles in breast tissue: a case-control study of cancer risk

Breast cancer remains the most prevalent cancer among women globally. Environmental exposures, particularly to trace elements (TEs) are emerging as significant risk factors. This case-control study investigated the concentrations and distribution of selected metals and metalloids in breast tissues from women in Isfahan, Iran. Breast tissue samples were collected from 43 newly diagnosed breast cancer patients (tumor and adjacent non-tumor tissues) and 40 healthy women undergoing cosmetic breast surgery. Demographic data (age, body mass index (BMI), education, family history, smoking) were collected via questionnaires. Tissue samples were digested using nitric acid and hydrogen peroxide at 90 °C and concentrations of elements were quantified using inductively coupled plasma mass spectrometry (ICP-MS). Significantly higher concentrations of cadmium (Cd), nickel (Ni), zinc (Zn), cupper (Cu), calcium (Ca), iron (Fe), and phosphorus (P) were observed in cancerous tissues compared with healthy controls (p < 0.05). Cd (7 ng/g vs. 1 ng/g) and Ni (696 ng/g vs. 141 ng/g) showed particularly elevated levels in tumor tissue, suggesting a potential role in breast carcinogenesis. Ca and P were markedly increased in cancerous tissue, consistent with pathological calcification processes. Breast cancer patients had a higher family history of cancer (35.29% vs. 8.33%, p = 0.002) than controls. This study provides direct evidence of altered accumulation and interaction of essential and toxic elements in breast cancer tissue. These findings highlight the potential contribution of environmental metal and trace elements exposure to breast cancer development and underscore the importance of tissue-based elemental analysis in elucidating disease mechanisms.