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 χ2 test 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.