Serum levels of rapid turnover proteins are decreased and related to systemic inflammation in patients with ovarian cancer

Poor nutritional status is common in ovarian cancer. It is well known that the nutritional status of a patient with malignant disease is associated with survival, and that it can be assessed by serum levels of rapid turnover proteins (RTPs), such as retinol binding protein, prealbumin and transferrin. Systemic inflammation, usually observed in the form of elevated C-reactive protein (CRP) or neutrophil/lymphocyte ratio (NLR), occurs by various mechanisms involving numerous pro-inflammatory cytokines. These include interleukin (IL)-17 and other soluble protein mediators, such as soluble IL-2 receptor (sIL-2R) and vascular endothelial growth factor (VEGF). In this study, circulating levels of RTP were decreased in advanced stages of ovarian cancer, and significant inverse correlations were found between RTP levels and serum levels of CRP or NLR. CRP levels were also correlated with serum levels of VEGF and sIL-2R. Moreover, NLR, VEGF and sIL-2R levels, and IL-17 production, were all inversely correlated with RTP levels. These findings indicate that chronic inflammation may be associated with compromised immune function, such as an impaired T-cell response, via various inflammatory proteins, including sIL-2R, VEGF and IL-17. The key mechanisms leading to cancer cachexia, in which nutritional impairment is a major clinical issue, appear to be primarily immune reactions caused by chronic inflammation. Anti-inflammatory treatments may be effective in clinically improving various symptoms associated with these mechanisms.