The relationship between tumour NF-kB expression, hormone status, and clinicopathological factors in primary invasive breast cancer.

Abstract

Abstract Abstract #4038 Breast cancer is one of the most common and lethal malignancies in the UK. Conventionally, prognosis is based on hormone status, tumour size, grade and lymph node involvement. Recently it has been proposed that Nuclear Factor Kappa B (NF-kB) is associated with breast cancer development and progression (1). The aim of the present study was to examine the relationship between NF-kB, hormone status and clinicopathological factors in primary invasive breast cancer.
 Immunohistochemistry was performed on 168 breast tumour sections, with full clinicopathological characteristics. Antibodies were directed against total NF-kB and NF-kB phosphorylated at serine 536 (phospho NF-kB). Two observers independently scored expression using the weighted histoscore technique and grouped tumours as having high or low expression according to the median value.
 Cytoplasmic and nuclear NF-kB expression, either total or phosphorylated did not correlate with grade, size or lymph node involvement. However, nuclear phospho NF-kB expression was inversely associated with Ki67 proliferation index (p<0.05). In addition an association between total nuclear NF-kB (p<0.050) and total cytoplasmic NF-kB (p<0.05) was observed with oestrogen (ER) and progesterone receptor (PR) status, total NF-kB expression was higher in ER and PR positive tumours (n=53) compared with ER negative and PR negative tumours (n=34). This association was also observed for nuclear phospho NF-kB (p<0.001) but not cytoplasmic phospho NF-kB (p=0.292). In addition, ER positive and PR negative tumours (n=78) had reduced nuclear phospho NF-kB (p<0.001) and cytoplasmic phospho NF-kB (p<0.001) expression when compared with ER positive and PR positive tumours (n=53).
 These results suggest that reduced tumour expression of phospho NF-kb is associated with increased cell proliferation and PR negativity but not ER negativity in primary invasive breast cancer. The impact of such differential tumour expression of phospho NF-kB on outcome in breast cancer remains to be determined.
 1. Cao Y, Karin M. NF-kappaB in mammary gland development and breast cancer.J Mammary Gland Biol Neoplasia. 2003;8:215-23. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4038.