asco@alo33:161940 JSONTXT

Background: Fatigue is a distressing side effect of cancer therapy. Emerging evidence suggests immunological involvement in the pathogenesis of chronic fatigue CF related to radiation therapy RT for cancer. We hypothesize that changes in immunological markers underlie chronic fatigue symptoms in men ith non-metastatic prostate cancer NM-PC patients ho have previously received localized external beam RT EBRT . Methods: A sample of 34 men ith NM-PC scheduled to receive EBRT ere folloed at baseline and one year folloing EBRT completion. Demographic and clinical data ere obtained by chart revie. The Functional Assessment of Cancer Therapy-Fatigue FACT-F as administered to measure fatigue levels. Blood as dran at baseline and one year after EBRT. Plasma cytokine levels ere determined using the Bio-Rad Bio-Plex Cytokine Assay Kits. Gene expression profiles ere determined using microarray analysis and analyzed using Partek Genomics Suite 6.6 as ell as Ingenuity Pathay Analysis. Results: At one year after EBRT completion, 34 percent of subjects continued to experience persistent fatigue, defined as a decrease in FACT-score of 3 points or greater from baseline. One year folloing EBRT, microarray analysis revealed 44 genes that ere differentially expressed beteen the CF and non-fatigue NF groups. The main disease netorks identified by pathay analysis of the differentially expressed genes are related to cancer pathophysiology. Further, there as an increase in gene expression levels of the decoy receptor TRAIL-R3in the CF group. Interestingly, the ligand of this decoy receptor, TRAIL, is significantly higher in the plasma of CF subjects compared to NF subjects. Conclusions: Concomitant upregulation of TRAIL and its decoy receptor suggest that fatigue may be more than just a distressing side effect of cancer treatment. Instead, fatigue symptoms may serve as a behavioral indicator of the underlying disease status in cancer patients.,J Clin Oncol 34, 2016 suppl; abstr 10113 00:00.0,Patient and Survivor Care