Interleukin– 2 and 6 Levels in Nigerian Men with Prostate Cancer

Abstract

Prostate cancer is one of the leading causes of cancer mortality in Nigerian males. Multiple cytokines play a role in the 
aetiopathogenesis of prostate cancer. Interleukin – 2 (IL-2) and – 6 (IL-6) have been identified in the evolution of prostate cancer 
with possible therapeutic applications. The goal of this study was to investigate the serum levels of these cytokines in Nigerian 
males with prostate cancer. This was a longitudinal study of 40 serially recruited patients with prostate cancer and 40 age- and 
sex matched-controls. Blood sample was taken from participants after obtaining informed consent. The samples were processed 
and analysed for prostate specific antigen (PSA), free PSA, IL-2, and IL-6. Plasma levels of IL-2 and IL-6 were significantly 
elevated in individuals with prostate cancer and directly correlated with plasma PSA and free PSA. The PSA and free PSA levels 
were also significantly higher in the study group than the control group. The %free PSA was < 25% in all study individuals with 
malignant prostate cancer and most patients had advanced disease with a Gleason score of 7-9. The high plasma level of IL-2 in 
individuals with prostate cancer found in this study suggests active immune response; however, the failure to suppress 
malignancy may be due to activity modulation in the tumour microenvironment. Observed increase in IL-6 may contribute to 
disease progression by its direct androgenic action to prostate cancer cells. Hence, the prevalence of advanced disease in this 
study population may be the result of impaired IL-2 antitumour action and increased IL-6 activity.