Abstract
StAR-related lipid transfer domain containing proteins (STARD3) are a group of proteins that contain a steroidogenic acute regulatory protein-related lipid transfer domain. Breast cancer (BC) has been linked to the STARD3 gene. In this study, we sought to confirm the relationship of STARD3 protein expression with clinicopathological characteristics and BC molecular subtypes. Using tissue microarray, we examined the STARD3 protein expression in 200 BC tissues and 20 normal breast tissues. Higher protein expression of STARD3 was found in tumor tissues than normal tissues. One hundred and fifty-two (69.1%) of the 200 cases tested positive for STARD3 (high H-score), while seventy (30.9%) had a low STARD3 H-score. When STARD3 is present, its expression ranges from mild to strong. STARD3 H-score was strongly linked to human epidermal growth factor receptor 2 (HER2)-positive (p < 0.001) and estrogen receptor (ER)-positive (p < 0.009) patients, but not to triple-negative BC patients. STARD3 high H-score was associated with histological grade and tumor size. No significant associations were found with stage of the disease, pathological stage or node status. Our research revealed that STARD3 levels were higher in tissues from malignant BC, and it was associated with HER2 and ER, suggesting that it might be utilized as a marker for BC.