The association between KRAS mutational status, clinicopathological factors including the preoperative systemic inflammatory response and outcomes in TNM stage I-III colon cancer.

193 Background: TNM Stage is the most significant prognostic indicator in colon cancer however other tumour and host factors (eg the systemic inflammatory response (SIR)) are associated with long-term outcomes. The relationship between the tumour and the host SIR remains poorly understood. KRAS mutations are associated with adverse outcomes in metastatic disease and have been reported to have an inflammatory phenotype however this has not been widely studied in non-metastatic disease. The present study investigates the association between KRAS mutations, clinicopathological factors including the SIR and outcomes in TNM I-III colon cancer. Methods: Two cohorts of patients (single centre–2000-2008 and regional-2011-2014) undergoing curative surgery for TNM I-III colon cancer in the West of Scotland were shown to be well-matched and combined. Mutational status was analysed retrospectively. The SIR was stratified using Systemic Inflammatory Grade (SIG). 3-year overall and cancer specific survival (OS and CSS) were measured from date of surgery until date of death. Results: 267 patients were identified, 45% with KRAS mutations. KRAS mutations were associated with: right sided (p=0.013), well differentiated (p=0.011), BRAF-wt (p<0.001), PIK3CA-wt (p=0.027) and P53-wt (p=0.002) tumours. A trend was seen between KRAS mutations and female sex (p=0.074) and increased SIG (p=0.072). No association was seen with age, deprivation, smoking, ASA Grade, TNM Stage or EMVI. KRAS mutant status was associated with adverse 3-year CSS (74% versus 82%, p=0.006) and OS (69% versus 78%, p=0.070). For CSS, TNM Stage (HR 2.92, p<0.001), KRAS mutant status (HR 1.64, p=0.050) and Systemic Inflammatory Grade (HR 1.34, p=0.004) were independently prognostic. For OS: age (HR 1.39, p=0.022), TNM Stage (HR 1.50, p=0.016) and SIG (HR 1.25, p=0.005) were independently prognostic. A trend was seen between KRAS mutant status and adverse OS (HR 1.47, p=0.079). Conclusions: The present results show an association between KRAS mutational status and SIG. Furthermore, both of these factors were associated with adverse oncological outcomes. Further investigation into the association between KRAS-mutant status and the local/systemic inflammatory response in TNM I-III colon cancer is warranted. While comprehensive genomic profiling is likely to become increasingly common place, staging the host (SIR) should also be routinely undertaken.