ABSTRACT
- Luminal B (HER2 negative) subtype is the most diversiform type of breast cancers, with a high Ki-67 proliferation index (>20%) or/and low progesterone (PR; <20%) with various intensity and distribution of hormone receptors. Considerable difference has also been noticed in disease outcome, wherefore there is the need for a more detailed classification of this tumor subtype. The clinical and pathologic parameters of 147 luminal B (HER2 negative) breast cancers were examined. The expression of hormone receptors in correlation with other prognostic factors and disease outcome was analyzed by Kaplan-Meier curves and multivariate Cox regression analysis. The Kaplan-Mayer analysis showed that low positivity of estrogen (ER) and PR receptors in tumors was associated with a significantly worse disease outcome (overall survival (ER), p=0.020; disease free survival (ER), p=0.019; overall survival (PR), p=0.026; disease free survival (PR), p=0.038)), unlike Ki-67, which did not show a statistically significant connection (overall survival, p=0.343; disease free survival, p=0.322). The intensity of receptor staining and Ki-67 relative to other histopathologic prognostic factors showed a statistically significant correlation solely with histologic grade of tumor. By using the Cox regression model, PR proved to be an independent prognostic factor for overall survival (p=0.004) and disease free survival (p=0.029). The luminal B (HER2 negative) breast cancer with low expression of hormone receptors, independent of the Ki-67 proliferation index, and in correlation with a higher histologic grade, could be a unique subtype of cancer.
Subject(s)
Breast Neoplasms , Estrogens/metabolism , Progesterone/metabolism , Receptors, Estrogen/metabolism , Receptors, Progesterone/metabolism , Adult , Aged , Biomarkers, Tumor/metabolism , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Female , Humans , Middle Aged , Multivariate Analysis , Outcome Assessment, Health Care/methods , Outcome Assessment, Health Care/statistics & numerical data , Predictive Value of Tests , Prognosis , Survival AnalysisABSTRACT
Nectins are Ca2+-independent immunoglobulin (Ig) superfamily proteins that participate in the organization of epithelial and endothelial junctions and regulate several cellular activities including the entry of some viruses. Nectin-4 has recently been shown as a metastasis-associated protein in several cancers. In the following study, we have evaluated the expression of Nectin-4 inthe luminal B HER2 negative subtype breast cancer. The study group consisted of 147 patients presenting with primary unilateral breast carcinoma with no evidence of distant metastases. Nectin-4 protein expression was assessed by immunohistochemistry and the results were correlated with the clinical data using Kaplan-Meier curves, univariate and multivariate stepwise proportional-hazard analysis (Cox model). Nectin-4 overexpression was significantly correlated with the tumour size (p<0.05; Fisher's Exact Test), also Nectin-4 expression was negatively associated with overall survival, disease free survival and distant relapse free survival with the same significance (p<0,001; Kaplan-Meier, Cox model). We did not find statistically significant correlation between Nectin-4 and age, ER, PR, age, lymph node metastasis, tumour differentiation, histologicalsubtype and Ki-67proliferation index. We suggest that Nectin-4 is a relevant prognostic factor and a therapeutic target in luminalB (HER2 negative) breast cancer.
