Serum Galectin-3 Concentrations Differentiate Between Lobular and Ductal Carcinomas in Breast Cancer Patients

Abstract

Background Galectins are soluble proteins found intracellularly and extracellularly. They are carbohydrate binding proteins that play a role in adhesion, signaling, immune regulation, apoptosis, and other cellular processes. It has been established that galectin expression is altered in cancer pathogenesis, and that galectins are potential therapeutic targets for cancer treatment. However, little research has established the relationship between serum concentration of galectins and breast cancer subtypes. Breast cancer has a high incidence, and treatment is often specific to histological or molecular subtype. The current method for breast cancer subtype identification is an invasive biopsy. Our study analyzes the differences in galectin concentrations in breast cancer patients of different subtypes to establish potential biomarkers for less invasive cancer identification or targets for treatment. Methods Enzyme-linked Immunosorbent Assay (ELISA) was used to establish the concentrations of galectin -1, -3, -7, and -9 in 100 breast cancer patient serum samples. The galectin concentrations were compared by histological subtype, stage, and other patient characteristics. Statistical analysis of the results was performed using a Student’s T-test and the Wilcoxon Method. Results Samples from patients with invasive lobular carcinoma had significantly higher concentrations (mean, 13.04 ng/mL) of galectin-3 than invasive ductal carcinoma samples (mean, 9.32 ng/mL; p-value,: 0.0108). We also found that concentrations of galectin-1 increased by stage from breast cancer stages I to III, with a significant difference found between samples from patients with stage I breast cancer (mean, 19.02 ng/mL) and both stage II (mean, 24.15 ng/mL; p-value,: 0.0127) and stage III (mean, 28.37 ng/mL; p-value,: 0.0026) breast cancer. Conclusion Our results point to a potential use of serum galectin-3 concentrations to distinguish between lobular carcinoma versus ductal carcinoma and could offer a non-invasive diagnostic tool. Based on our results, research could be performed to further establish the relationship between galectin-3 and other breast cancer histological subtypes, as well as molecular subtypes.