Serum HSP-70 and XBP-1 as Diagnostic and Treatment- Monitoring Biomarkers in Breast Cancer

Abstract

Introduction: To lower breast cancer mortality, clinicians need non-invasive biomarkers for earlier detection and evaluating disease status. HSP-70 controls protein folding and XBP-1 directs the unfolded protein response (UPR). Tumors exploit these dysregulated pathways for survival and drug resistance. We tested serum HSP-70 and XBP-1 as markers for diagnosis and chemotherapy response.

Methods: The study included 90 women, ages 30 to 65, from the Anbar Governorate for a cross-sectional comparison. This study included 30 newly diagnosed breast cancer patients (Group A), 30 patients undergoing chemotherapy (Group B), and 30 age-matched healthy controls (Group C). ELISA measured serum concentrations of HSP-70 and XBP-1. We used Kruskal-Wallis, Mann-Whitney U, PCA, and ROC curve analyses to evaluate biomarker performance.

Results: Newly diagnosed patients showed elevated serum levels of both biomarkers compared to healthy and treated groups. Group A showed higher mean HSP-70 and XBP-1 levels (1.91 ng/ml and 146.84 pg/ml) than the control group (1.19 ng/ml and 120.91 pg/ml, p<0.001). Chemotherapy patients (Group B) had lower levels of HSP-70 (1.41 ng/ml) and XBP-1 (110.28 pg/ml) than the newly diagnosed group. HSP-70 (AUC = 0.969) and XBP-1 (AUC = 0.814) distinguished newly diagnosed patients from controls. The two markers correlated positively (r = 0.52).

Conclusion: Serum HSP-70 and XBP-1 levels are elevated in newly diagnosed breast cancer and appear lower in patients undergoing chemotherapy. Together, they show potential as an indicator panel for disease status, though longitudinal studies are required to confirm their utility in dynamic treatment monitoring.