Abstract P2-23-18: Analysis of Serum Galectin Profiles by Breast Cancer Subtypes and Patient Characteristics

Abstract

Abstract Background: Galectins are sugar binding proteins that play a role in adhesion, apoptosis, immune regulation, and many other cellular processes. There are three different classes of galectins, and they are all found intracellularly and secreted in serum. Galectins have an established relationship with breast cancer, and galectin-3 has been repeatedly associated with cancer cell survival and tumor progression. Most research regarding breast cancer and galectins has used immunohistochemistry (IHC) as a method for identifying galectin expression in breast cancer tissue samples. However, little research has identified a relationship between serum galectin concentrations and breast cancer subtypes. Breast cancer is characterized both by histological and molecular subtype, and this identification often directs treatment decisions. The current method for identifying breast cancer subtypes is through invasive biopsy and the subsequent use of IHC. This project characterized serum galectin concentrations in breast cancer patients to determine if they changed based on different histological and molecular subtypes, cancer stage, and other patient characteristics. Our goal was to evaluate a potential noninvasive means of breast cancer subtype identification and to identify potential therapeutic targets. Methods: One-hundred breast cancer patient serum samples were studied using Enzyme-linked Immunosorbent Assays (ELISAs) to determine concentrations of galectins -1, -3, -7, and -9. Results were compared using many patient characteristics, including breast cancer subtype, stage, and patient history (smoking status and treatment). Statistical Analysis was performed using ANOVA, Student’s t-test, and the Wilcoxon Method. Results: The concentrations of galectins -1, -3, and -9 in breast cancer patients were all significantly higher than those of healthy controls (Table 1), which is consistent with previous studies. The concentration of galectin-3 was significantly higher in invasive lobular carcinoma samples (N, 6; mean, 13.04 ng/mL) compared to invasive ductal carcinoma samples (N, 80; mean, 9.93 ng/mL; p-value, 0.0428). Galectin-3 concentrations were significantly lower in samples from breast cancer patients who received chemotherapy (N, 9; mean, 9.22 ng/mL) versus those who did not (N, 7; mean, 14.60 ng/mL; p-value, 0.0228). Concentrations of galectin-1 were found to increase by stage (p-value, 0.0031), with significant differences between samples from patients with stage I breast cancer (N, 45; mean, 19.02 ng/mL) and both stage II (N, 40; mean, 24.15 ng/mL; p-value, 0.0127) and stage III (N, 12; mean, 28.37 ng/mL; p-value, 0.0026) disease. Conclusions: Our findings suggest a potential use for serum galectin-3 concentrations as a non-invasive means for breast cancer histological subtype differentiation and more refined diagnosis. In addition, our results suggest a possible use of galectin-1 concentrations for more accurate cancer staging. Further research could explore the relationship of serum galectin concentrations and other breast cancer subtypes. Future studies could also analyze how galectin concentrations change with patient treatment status and determine the potential of galectins as specific targets for breast cancer treatment. Table 1: Galectin Concentrations in Breast Cancer vs Healthy Controls Citation Format: Jonah Shealy, Alex Kesic, Avery Funkhouser, Julie Martin, W. Larry Gluck, w. Jeffery Edenfield, Anna Blenda. Analysis of Serum Galectin Profiles by Breast Cancer Subtypes and Patient Characteristics [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-23-18.