Evaluation of LGR5 Cancer Stem Cell Marker Expression in Breast Cancer and Its Relationship with Hormonal Profile and Clinical Pathological Features

BACKGROUND: Due to the high prevalence of breast cancer and the importance of evaluating new prognostic criteria for effective treatment of these patients, this study was performed to investigate the role of LGR5 in breast cancer and its relationship with hormonal and clinicalopathological features of the disease. METHODS: This cross-sectional study was performed on breast cancer tissue samples in the archives of the pathology department of Firoozabadi Hospital in Tehran between 2019 and 2021. Inclusion criteria included invasive ductal carcinoma and exclusion criteria were preoperative chemotherapy. Blocks were examined for LGR5 marker expression by IHC method using LGR5 monoclonal antibody kits (Abcam). The expression pattern of LGR5 marker was cytoplasmic and cells presenting brown staining in the cytoplasm were considered positive for this marker and in terms of distribution and severity of staining were divided into three groups: mild, moderate and severe. RESULTS: This study was performed on 60 patients with breast cancer with a mean age of 55.5±9.7. Most of the patients (55%) were in grade II. The KI67 marker was positive in 45 cases (75%) and the HER2 marker in 14 cases (23.3%) and 8 cases (13.3%) were triple-negative. The expression severity of staining of LGR5 marker in 41 cases (68.3%) was moderate and the distribution of marker expression in 31 cases (51.7%) was moderate. No significant relationship was observed between LGR5 expression severity and tumor characteristics. CONCLUSION: LGR5 marker is expressed in a remarkable percentage of breast cancer patients and has no significant relationship with tumor characteristics.