The relationship between tumour necrosis, systemic inflammation, body composition and survival in patients with colon cancer Does tumour necrosis drive cachexia?

Abstract Background: In cancer cachexia the relationship between the tumour, its environment and the systemic inflammatory response is not clear. This study aims to examine this relationship in greater detail. Methods: Host characteristics included the presence of an SIR as measured by Systemic Inflammatory Grade (SIG), sarcopenia (SMI) and myosteatosis (SMD) were measured. Categorical variables were analysed using χ²test for linear-by-linear association, or χ² test for 2 by 2 tables. Survival analysis was carried out using univariate Cox regression. Results: 473 patients were included. 66% were over 65, 56% were male and 54.8% had an ASA grade of 1 or 2. Pathological examination showed that the majority of patients had a T3 (53.7%) or a T4 (34.0%) cancer and 73% had evidence of necrosis. A SIG score of 0 or 1 was present in 57.7% of patients. Tumour necrosis was associated with age (p<0.01), tumour location (p<0.01), T-stage (p<0.001), margin involvement (p<0.05), SIG (p<0.001), SMI (p<0.01), SMD (p<0.05) and 5-year survival (p<0.001). On univariate survival analysis necrosis (p<0.01), SIG (p<0.001), SMI (p<0.01) and SMD (p<0.05) were independently associated with overall survival. Conclusion: These results suggest that tumour necrosis and the subsequent inflammatory response results in profound changes in body composition.