Relationship between circulating cytokine levels and physical or psychological functioning in patients with advanced cancer

Objective: To investigate the relation between functional impairments of cancer patients and circulating cytokines using a multiplex technique. Design and methods: 50 patients with cancer were assessed using the quality of life (QOL) questionnaire. 27 plasma cytokine levels were determined by using the Bio-Plex array system. The relation to QOL scores was assessed using Chi-square test for categorical variables and univariate linear regression analysis for cytokine levels. Results: Multivariate analysis showed that interleukin-6 (IL-6) level is a significant independent determinant of physical (beta=-0.238, P=0.0126) and cognitive functioning (beta=-0.462, P=0.0006) and that vascular endothelial growth factor (VEGF) level is a significant independent determinant of emotional functioning (beta=-0.414, P=0.039). Conclusion: This study, in which 27 cytokines are simultaneously tested with cutting edge technology, demonstrates that plasma IL-6 and VEGF are significant independent determinants of functional impairments in patients with cancer. (C) 2011 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.