Background
Prognosis following resection for colon cancer improves with higher lymph node yields. To date, this has been attributed to superior surgical technique and excellence in pathology. However, in an era of standardisation and sub-specialty training the wide variance in lymph node yields cannot be fully explained thus. Pre-operative elevated markers of systemic inflammation also affect prognosis, a finding largely explained by an immunogenic response to cancer. We hypothesise that lymph node count and systemic inflammatory response are linked.

Method
A prospectively maintained database was interrogated. All patients undergoing curative colonic resection were included. Neutrophil lymphocyte ratio (NLR) and albumin were used as markers of systemic inflammatory response (SIR). In keeping with previously studies, NLR >/= 4, Albumin <35 was used as cut off points for SIR. Statistical analysis was performed using 2 sample t-test and chi square tests where appropriate.

Results
302 patients were included for analysis. 195 patients had nlr <4 and 107 had nlr >/= 4. There was no difference in age, sex or disease stage between groups. Patients with NLR of >/= 4 had lower mean lymph node yields than patients with NLR <4(17.6 +/- 7.1 vs. 19.2 +/- 7.9 (P=0.036)). Patients with hypoalbuminaemia at diagnosis tended towards lower lymph node yields.

Conclusion
Prognosis in colon cancer is intimately linked to the patient’s immune response. Assuming standardised surgical technique and sub specialty pathology, lymph node count is reduced when systemic inflammatory response is activated.