Plasma Cadmium Concentrations Among Women with Breast Cancer in Abuja, Nigeria: A Case–Control Study

Background Breast cancer remains the most frequently diagnosed cancer among women worldwide and a leading cause of cancer-related mortality. Environmental exposure to cadmium, a recognized human carcinogen, has been implicated in breast carcinogenesis through multiple biological mechanisms, but data from sub-Saharan Africa remain limited. Objective To compare plasma cadmium concentrations between women with breast cancer and age-matched apparently healthy controls attending a tertiary hospital in Abuja, Nigeria. Methods This hospital-based case–control study included 70 treatment-naïve women with histologically confirmed breast cancer and 70 age-matched apparently healthy controls recruited from the National Hospital Abuja between 2022 and 2024. Plasma cadmium concentrations were measured using atomic absorption spectrophotometry at an analytical wavelength of 228.8 nm. Values below the analytical limit of detection (0.009 µg/mL) were considered non-detectable and assigned a value of zero for statistical analysis. Continuous variables were summarized as medians and interquartile ranges (IQRs), and group comparisons were performed using the Mann–Whitney U test. Statistical significance was set at p < 0.05. Results Plasma cadmium concentrations were significantly higher among women with breast cancer than among apparently healthy controls (median [IQR]: 0.91 [0.61–1.06] µg/mL vs. 0.00 [0.00–0.00] µg/mL; p < 0.001). Cadmium was detectable in most women with breast cancer, whereas concentrations among the control participants were below the analytical limit of detection. Conclusion Treatment-naïve women with breast cancer in Abuja, Nigeria, had significantly higher plasma cadmium concentrations than age-matched apparently healthy controls. These findings support a possible association between environmental cadmium exposure and breast cancer and contribute to the limited evidence on environmental risk factors for breast cancer in sub-Saharan Africa. Larger multicentre prospective studies incorporating detailed environmental exposure assessment are warranted to further clarify this relationship. Keywords: Breast cancer; cadmium; environmental exposure; atomic absorption spectrophotometry; case–control study; Nigeria.