Contribution of diet, tumour volume and patient-related factors to weight loss in patients with colorectal liver metastases

Background: One of the difficulties in assessing the contribution of tumour -related factors to cancer cachexia is measurement of the extent of disease where dissemination to multiple organ sites has occurred. Methods: In this study the extent of tumour (both tumour volume and increas e in marker levels), diet and patient-related factors (appetite, metabolic hormones, immune activation, liver function and quality of life) were compa red in patients with colorectal liver metastases who had lost at least 1 kg in body-weight (weight loss) and patients who had not lost 1 kg in body we ight (stable weight) during the preceding month. Results: Forty patients (22 men; 14 with weight loss) were studied. Liver m etastasis volume was significantly greater in patients who lost weight than in those whose weight was stable (median (interquartile range) 1179 (245-1 517) versus 119 (23-523) ml; P = 0.003). The prevalence of patients with ra ised levels of serum immune products was significantly greater in the weigh t loss group for soluble interleukin (IL) 2 receptor alpha (sIL2r alpha) (P = 0.03) and IL-6 (P = 0.05), but not for soluble tumour necrosis factor re ceptor 1 (sTNFr1) or neopterin. There were significant correlations between serum C-reactive protein and sIL2r alpha (r(s) = 0.68, P < 0.0001) and IL- 6 (r(s) = 0.46, P = 0.008) but not sTNFr1 or neopterin levels. Significant differences in appetite, nausea, diet, energy intake, liver function tests and serum levels of metabolic hormones were not detected. Conclusion: Weight loss in patients with colorectal liver metastases was no t explained by changes in diet, quality of life, or hormones, but activatio n of the innate and incomplete activation of the acquired immune systems ma y be involved. Agents that attenuate either the acute-phase inflammatory re sponse or T lymphocyte IL-2 receptor upregulation might reduce weight loss in patients with metastatic disease.