Circulating Cytokine Levels in Patients with Prostate Cancer: Effects of Neoadjuvant Hormonal Therapy and External-beam Radiotherapy.

ABSTRACT

AIM: The aim of the study was to better characterize the temporal induction of inflammatory cytokines in the serum of patients with prostate cancer (PCa) treated with radiotherapy and to ascertain the influence of hormonal therapy upon those expressions. PATIENTS AND METHODS: Between May 2007 and December 2009, 30 patients with localized PCa were treated with 3-dimensional conformal external-beam radiotherapy. Fifteen patients had received neoadjuvant hormonal therapy using a leuteinizing hormone-releasing hormone (LH-RH) analog for six months prior to radiotherapy. The cytokine levels were collectively measured using a multiplex assay system. RESULTS: Seventeen cytokines were at detectable levels throughout the blood sampling times before and during radiotherapy. Hormonal therapy for six months significantly decreased the serum levels of fibroblast growth factor-2 (FGF2) and vascular endothelial growth factor (VEGF). The levels of epidermal growth factor (EGF), granulocyte-colony stimulating factor (G-CSF), and interferon-gamma (IFNγ) significantly increased during radiotherapy. Most cytokine levels, except for eotaxin, G-CSF, growth-related oncogene (GRO), transforming growth factor-beta (TGFß)-1 and TGFß2, significantly increased during radiotherapy compared to the levels observed before radiotherapy. CONCLUSION: The present study revealed the influence of hormonal, and of radiation therapy on the proinflammatory cytokine levels in the sera of patients with PCa. In addition, neoadjuvant hormonal therapy amplified the radiation-induced alteration of serum cytokines. Further studies to characterize the mechanism underlying a radiation- or hormone-induced inflammatory state are, therefore, necessary.