Levels of plasma cytokine in patients undergoing neoadjuvant androgen deprivation therapy and external beam radiation therapy for adenocarcinoma of the prostate

Background: Radiotherapy (RT) alone or in combination with androgen deprivation therapy (ADT) is most common non-operative treatments for localised prostate cancer (PC). Some circulatory cytokines are believed to play an important role in RT resistance and lead to tumour progression, invasion, and angiogenesis. The aim of this study is to assess the influence of ADT and RT on the expression of circulatory cytokines levels in plasma at different time points.

Methods: Between Nov 2015 and Aug 2016, 18 patients with localized PC were selected for this clinical study. All patients had received neoadjuvant ADT using a leuteinizing hormone-releasing hormone (LH-RH) analogs prior to RT. Peripheral blood samples were collected prior to ADT, before RT, at the end of RT and 3 months after the completion of RT. Blood plasma samples were monitored for the pro-inflammatory and profibrotic cytokines TNF-α, TGF-β1, IL-6, and IL-8, using enzyme-linked immunosorbent assay (ELISA) procedures.

Results: The concentration of TGF-β1 rose while IL-6 levels declined in post-ADT samples when compared pre-ADT. Levels of TGF-β1 increased in post-RT blood plasma compared to pre-RT blood plasma. Those changes were not statically significant. Three months post-RT completion, TGF-β1 levels decreased and IL-6 and IL-8 levels increased. Although levels of TGF-β1, IL-6 and IL-8 were found to be altered 3 months post-RT completion, only changes in IL-8 levels were found to be statistically significant (P=0.05).

Conclusions: In conclusion the changes in cytokines levels have been found after ADT and RT, which strengthen the finding of other clinical studies. Accept that small numbers of samples made difficult to attain significant results. Large clinical studies will be required to validate these findings and hopefully become useful biomarkers in the clinical setting to predict patient outcome and success of treatment received.