Long Term Outcome of Surrogate Subtypes of Primary Operable Breast Cancer According to Securin Expression

Abstract

Abstract Background: Despite dramatic advances in cancer research, breast cancer remains a major health problem. In this heterogeneous disease, patients with different molecular subtypes have a different therapeutic approach and prognosis. Securin is known to participate in maintaining chromosomal integrity during the cell cycle through regulation of metaphase-anaphase transition, DNA damage repair and apoptosis. The aim of this study was to evaluate the prognostic role of securin expression as a measure of chromosomal instability in different surrogate subtypes of breast cancer in order to discriminate patients with worse prognosis. Materials and methods: Breast cancer paraffin-embedded tissue specimens were obtained from a consecutive series of 215 patients with primary operable invasive breast carcinomas referred to the University Hospital Centre Zagreb, Croatia, from 2002 to 2003. Immunohistochemical (IHC) staining for securin was performed, and all relevant clinical and histopathological data were collected. Surrogate subtypes were defined according to St Gallen's consensus criteria. All patients were followed-up prospectively according to standard institutional practise for local and distant reccurence and death to collect data on disease-free (DFS) and overall survival (OS). Results: In this patient cohort, median securin expression was 7 % of positive cells, ranging from 1 % to 42 %. Statistically significant correlation between tumor size and securin expression (p = 0.0272) and securin and Ki 67% expression (p = 0.0065) was shown. Securin expression differs among surrogate subtypes of breast cancer with highest expression in HER2+ subtype (median= 12). Univariate analysis has shown that in luminal A subtype and triple negative subtype there is statistically significant correlation between securin expression and DFS as well as OS. According to logistic regression analysis, it has also been shown that securin expression was independent prognostic factor for ten-year overall survival (OS). Conclusion: Our study has shown that patients with BC overexpressing securin have a worse long-term prognosis in comparison with those without overexpression but only in luminal A like and triple negative like surrogate subtypes.