Association Between BARD1 Polymorphisms, Immunological and Hormonal Markers, and Breast Cancer Risk in Iraqi Women

Background: Breast cancer is a leading cause of cancer-related mortality worldwide. Genetic factors, including polymorphisms in DNA repair genes such as BARD1, may influence susceptibility. Inflammatory and tumor markers also play a role in cancer progression. This study aimed to investigate the association between BARD1 exon mutations, immunological and hormonal markers, and breast cancer risk in Iraqi women. Methods: This case-control study comprised 100 patients with early-onset breast cancer and 100 healthy controls, frequency-matched for age and Body Mass Index (BMI). Serum levels of BARD1, MUC-1, CEA, CA15-3, estrogen, progesterone, prolactin, IL-1β, and TNF-α were measured using ELISA. Five BARD1 SNPs were genotyped using direct sequencing, and their association with breast cancer risk was assessed using logistic regression. The discriminative potential of the biomarkers was evaluated using Receiver Operating Characteristic (ROC) curve analysis. Results: Significantly elevated levels of IL-1β, TNF-α, CEA, BARD1, and MUC-1 were observed in the patients (p < 0.0001). ROC analysis showed discriminative potential for IL-1β (AUC = 0.88, 95% CI: 0.83–0.94), CEA (AUC = 0.78, 95% CI: 0.70–0.86), BARD1 (AUC = 0.77, 95% CI: 0.69–0.85), and MUC-1 (AUC = 0.73, 95% CI: 0.65–0.81). Three SNPs (rs2106145710, rs1695783243, and rs1574847014) were associated with increased breast cancer risk (rs1574847014 OR = 11.67, 95% CI: 3.5–38.8), whereas rs10498023 showed a protective effect (OR = 0.33, 95% CI: 0.22–0.51). Conclusion: Elevated levels of inflammatory and tumor markers, along with specific BARD1 polymorphisms, are associated with breast cancer risk in Iraqi women. These biomarkers may serve as noninvasive diagnostic tools, and genetic screening could aid in early risk stratification.