Lymphocyte Function at Baseline Could Be a New Predictor of Tumor Burden following Six Cycles of Radium-223 Therapy in Patients with Metastasized, Castration-Resistant Prostate Cancer

Abstract

Previous data indicate that one cycle of treatment with radium-223 (223Ra) did not significantly impair lymphocyte function in patients with metastasized, castration-resistant prostate cancer. The aim of the current study was to assess in 21 patients whether six cycles of this therapy had an effect on lymphocyte proliferation and interferon-γ and interleukin (IL)-10 ELISpot results. Lymphocyte proliferation after stimulation with microbial antigens and the production of interferon-γ continuously decreased after six cycles of radionuclide therapy, reaching statistical significance (p p r = −0.82). As determined by receiver operating characteristic (ROC) curve analysis, tetanus-specific IL-10 spots at baseline had the highest predictive value (p = 0.005) for tumor burden at month 6, with an area under the curve (AUC) of 0.90 (sensitivity 100%, specificity 78%). In conclusion, we observed an additive effect of treatment with 223Ra on immune function and found that IL-10 secretion at baseline predicted tumor burden at month 6 after treatment.

Keywords

• radium-223 therapy
• antimicrobial immune response
• lymphocyte proliferation
• ELISpot
• interferon-γ
• interleukin-10