Relation between depression and circulating immune products in patients with advanced colorectal cancer

We have previously suggested that colorectal liver metastases might produce 'toxins' that reduce both quality of life (QoL) and survival. In this study we assessed whether QoL in patients with such metastases was related to immune activation, as determined by increased serum levels of interleukin 6 (IL6), soluble tumour necrosis factor receptor 1 (sTNFr1), soluble interleukin 2 receptor alpha (sIL2r alpha) or the interferon-gamma marker neopterin. Serum IL6, sTNFr1, sIL2r alpha, neopterin, alkaline phosphatase and carcinoembryonic antigen levels, liver metastasis volume, and QoL (Hospital Anxiety and Depression [HAD] scale, Rotterdam Symptom Checklist [RSC], and Sickness Impact Profile [SIP]) were measured in 43 patients. There were significant positive correlations between serum sIL2r alpha and HAD depression score (r = 0.66, P = 0.0001), RSC physical symptom score (r = 0.46, P < 0.01), and SIP score (r = 0.47, P = 0.009). Multiple regression analysis suggested that serum sIL2r alpha level was a significant independent predictor of HAD depression score. Although survival was shorter (logrank test P < 0.05) where sIL2r alpha, sTNFr1 and IL6 levels were higher, the ability of sIL2r alpha to predict HAD depression score was independent of survival.