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 a Systemic Inflammatory Response (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 and multivariate Cox regression.

Results:
A total of 473 patients were included. Of these, 70.4% were over 65 years of age, 54.8% were male and 49.8% 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 73.0% 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 multivariate survival analysis in patients with T3 cancers age (HR: 1.45 95% CI 1.13–1.86 p < 0.01), ASA grade (HR: 1.50 95% CI 1.15–1.95 p < 0.01) and SIG (HR: 1.28 95% CI 1.11–1.48 p < 0.001) remained independently associated with survival.

Conclusion:
These results suggest that tumour necrosis and the subsequent SIR could result in profound changes in body composition and survival. Further pre-clinical and clinical work is required to prove causation.