Identification of neutrophil-derived proteases and angiotensin II as biomarkers of cancer cachexia

Background: Cachexia is a metabolic disorder characterised by muscle wasting, diminished response to anti-cancer treatments and poor quality of life. Our objective was to identify blood-based biomarkers of cachexia in advanced cancer patients. Hence, we characterised the plasma cytokine and blood cell mRNA profiles of patients grouped in three cohorts: patients with cachexia, precachexia (no cachexia but high CRP levels: >= 5mg l(-1)) and no cachexia (no cachexia and CRP: <5mg l(-1)). Methods: A total of 122 newly diagnosed cancer patients with seven cancer types were studied prior to their initial therapy. Plasma levels of 22 cytokines were quantified using the bio-plex technology. mRNAs isolated from whole blood and expression profiles were determined by the chip array technology and Ingenuity Pathway Analysis (IPA) software. Results: In comparison with non-cachectic individuals, both pre-cachectic and cachectic patients showed an increase (>= 1.5-folds) in mRNA expression of neutrophil-derived proteases (NDPs) and significantly elevated angiotensin II (Ang II) (P = 0.005 and P = 0.02, respectively), TGF beta 1 (P = 0.042 and P=0.0001, respectively) and CRP (both P<0.0001) in the plasma. Moreover, cachectic patients displayed a significant increase in IL-6 (P = 0.005), IL-8 (P = 0.001) and absolute neutrophil counts (P = 0.007). Conclusions: Ang II, TGF beta 1, CRP and NDP are blood biomarkers for cancer cachexia. These findings contribute to early diagnosis and prevention of cachexia.