Abstract
Objectives: To investigate the association of β-galactoside α2-6 sialyltransferase 1 (ST6GAL1) expression with hormone receptor (HR), human epidermal growth factor receptor 2 (HER2), and other clinicopathological parameters, including histological grade, stage, lymphovascular invasion, perineural invasion, and survival in breast carcinomas (BCs). Methods: This study included 85 patients who had undergone surgery for breast cancer (BC). The associations of HR, HER2 status, and histopathologic tumor characteristics with immunohistochemical expression of ST6GAL1 were analyzed. Results: The majority (48 [56.5%]) of patients were in the T2 stage, and no association was seen between staging and ST6GAL1 (p<0.05). Further, 44 (54.2%) patients were HR positive, and most of them exhibited high ST6GAL1 levels (p=0.001), whereas 44 (51.8%) were HER2 negative, and most of them demonstrated low ST6GAL1 levels (p=0.007). Ki-67 of ≥20% was observed in 55 (64.7%) and <20% in 30 (35.3%) patients. Most of those with high Ki-67 demonstrated low-grade STLGAL1 expression; however, no correlation was detected between the two values (p=0.378). High and low ST6GAL1 expressions were observed in 39 (45.9%) and 46 (54.1%) cases, respectively. Conclusion: This research is one of the first studies to use ST6GAL1 in preoperative biopsies of patients not scheduled for neoadjuvant treatment. This study revealed highly significant associations of ST6GAL1 expression with HR, HER2, and molecular subtyping. Future studies are recommended to clarify the possible role of ST6GAL1 in resistance to HR and HER2-targeted and other chemotherapeutic agents in BCs.