Nuclear Factor-κB Clinical Significance in Breast Cancer: An Immunohistochemical Study

OBJECTIVES: Nuclear factor κB (NF-κB) is a superfamily of transcription factors that plays a key role in cancer genesis and progression. The present study aimed to examine the expression of NF-κB/p65 in breast cancer and its relationship with prognostic markers such as tumour grade, tumour size, hormone receptors, and HER-2. METHODS: Ninety-nine unselected formalin-fixed paraffin-embedded invasive ductal and lobular tissue sections were evaluated by immunohistochemistry methods to measure the expression of NF-κB/p65, oestrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2 (HER-2), and Ki-67. We assessed the correlation between NF-κB/p65 and clinicopathological parameters. RESULTS: NF-κB/p65 was found only in the cytoplasm and positively correlated with large tumours (≥2 cm) and high-grade tumours (p < 0.001 and p = 0.018, respectively). Other breast cancer markers, such as histological type (p = 0.766), HER-2 (p = 0.416), PR (p = 0.356), and ER (p = 0.606), had no significant link with the expression of NF-κB/p65. Furthermore, no significant relation with the Ki-67 marker was detected (p = 0.117). CONCLUSIONS: The current study is indicative of a link between overexpression of NF-κB/p65 and both large tumour size and higher grade. This suggests that the expression of NF-κB/p65 is associated with aggressive biological activity in breast cancer; elucidating the mechanisms that lead to NF-κB/p65 cytoplasmic accumulation could lead to the development of novel therapeutic methods.