RESUMO
BACKGROUND: Elevated serum levels of soluble PD-L1 (sPD-L1) have been reported in many cancers; however, there is limited data of sPD-L1 in breast cancer, especially those representing Asian (Malay) women. The purpose of this study was to evaluate sPD-L1 serum levels and analyze its correlation with clinical characteristics in breast cancer patients at Hospital Universiti Sains Malaysia (HUSM). METHODS: Blood specimens were obtained from 92 malignant, 16 benign breast cancer patients and 23 healthy controls. The serum concentrations of sPD-L1 were assessed by enzyme-linked immunosorbent assay (ELISA). RESULTS: The median serum sPD-L1 concentration of malignant and benign breast cancer patients was significantly elevated compared to the healthy cohorts (12.50 ng/mL vs 13.97 ng/mL vs 8.75 ng/mL, p < 0.05). Optimal cut-off value of serum sPD-L1 for predicting disease progression was 8.84 ng/mL. Elevated serum sPD-L1 levels were significantly associated with menarche age, ethnicity, birth control usage, comorbidity and HER2 status (p < 0.05). Multivariate analysis showed the menarche age and birth control were the independent factors affecting sPD-L1 expression. CONCLUSION: Elevated serum levels of sPD-L1 were significantly associated with several clinical characteristics and warrant further investigation in evaluating patients pre-diagnosed with breast cancer.
