Background: The importance and relevance of serum inflammation biomarkers and DNA methylation-dependent micronutrients in breast tumorigenesis is gaining wider acceptance. However, the association of serum inflammation biomarkers and micronutrient status with expression of estrogen receptors (ER), progesterone receptors (PR) and human epidermal growth factor receptor-2 (HER-2) by the tumor has not been investigated in Nigerian breast cancer patients. The objective of this study was to determine the levels of serum biomarkers of inflammation [Homocysteine, Nitric Oxide (NO), Hydrogen peroxide (H2O2), Myeloperoxidase (MPO), Tumor necrosis factor alpha (TNF-α), Interleukins 6 and 8 (IL-6 and IL-8)] and DNA methylation-dependent micronutrients [Zinc (Zn), Folic acid, Vitamin B6 and B12] in breast cancer patients with different hormone receptors (ER, PR and HER-2). Methods: One hundred and fifteen women (80 with breast cancer and 35 controls) were randomly recruited for this study. Serum levels of homocysteine, folic acid, vitamins B6, vitamin B12, TNF-α, IL-6 and IL-8) were analyzed using ELISA, while the levels of NO, MPO, H2O2 and Zn were determined using spectrophotometer in patients with breast cancer and control subjects without breast cancer as well as breast cancer patients with ER, PR and HER-2 expression were determined. Results: The results showed that mean serum levels of IL-6 (P=0.002), IL-8 (P=0.018) and H2O2 (P=0.000) were significantly increased while TNF-α (P=0.014) and NO levels (P=0.044) were significantly decreased in breast cancer patients compared to healthy controls. However, there were no statistically significant differences in the levels of Zn, homocysteine, Vitamin B6, Vitamin B12 and MPO in breast cancer patients and controls. Furthermore, the levels of serum inflammatory biomarkers and methylation-dependent micronutrients were similar in breast cancer patients with HER-2, ER and PR expression. Conclusion: Systemic inflammation exists in breast cancer patients but the inflammation biomarkers and methylation-dependent micronutrients did not differ among breast cancer patients with PR, ER and HER-2 expression.
