Cytoplasmic Mineralocorticoid Receptor Expression Predicts Dismal Local Relapse-free Survival in Non-triple-negative Breast Cancer

Background/Aim: The aim of the study was to investigate the prognostic role of androgen receptor (AR), mineralocorticoid receptor (MR) and glucocorticoid receptor beta (GR beta) expression in HER-2 negative breast cancer patients. Materials and Methods: The study population (n=152) was enriched with triple-negative breast cancers (TNBC) (n=96; 63.2%). The median follow-up time was 100 months. AR, MR and GR beta immunocytochemical staining was compared with that of epithelial-mesenchymal transition (EMT) markers (vimentin, SIP1, ZEB1). Results: High expression of cytoplasmic MR was associated with dismal local relapse-free survival (RR=13.923; 95%CI=1.071-181.045; p=0.044) in tumours with non-TNBC phenotype. AR and GR beta were more frequently expressed in ER+/PR+/HER2-tumours, while cytoplasmic MR was more often expressed in TNBC tumours (for all, p<0.0005). GR beta and AR were associated with decreased vimentin expression (p<0.005), indicating their association with attenuated EMT. Conclusion: Cytoplasmic MR expression is a strong predictor of local recurrence in non-metastatic breast cancer patients with non-TNBC tumour phenotype.