Association of ongoing systemic inflammatory response (SIR) at diagnosis with lymph node retrieval and node positivity in patients undergoing surgery for colonic cancer.

Abstract

550 Background: Prognosis in colonic cancer is largely based on pathological criteria such as TNM staging. However, there are deficiencies in this approach and the lymph node ratio (LNR) has been promoted as improving prediction of outcomes. In this context retrieval of lymph nodes and their examination is of considerable importance. Kennelly et al (World J Gastrointest Oncol 2016) in a recent study, in 331 patients undergoing surgery for colon cancer, reported an elevated LNR and lower lymph node retrieval in those patients with a SIR. In the present study these relationships were examined in a larger cohort of patients (n = 881). Methods: A prospectively maintained database of all patients undergoing elective curative colonic resection in our institution was examined. The SIR was measured by scores mGPS (C-reactive protein/ albumin), NLR (neutrophils/ lymphocytes), PLR (platelets/ lymphocytes) and LMR (lymphocytes/ monocytes) using standard thresholds mGPS (0,1,2), NLR ( ≥ 5), PLR ( ≥ 150) and LMR ( ≤ 2.4). Statistical analysis was carried out in SPSS using Independent Mann Whitney U and Kruskal-Wallis tests where appropriate. Results: Of the 881 patients included in the study, 467 (53%) were male, 414 (47%) female, the median lymph node count was 16 (0-48) and the median LNR in patients with positive nodal disease was 0.13 (0.02-1). There was a significant relationship between increased lymph node retrieval and laparoscopic surgery (p = 0.01), age < 70 (p = 0.021), lower BMI (p = 0.047), right sided tumours (p < 0.001), lymphatic invasion (p = 0.02) and neoadjuvant treatment (n = 0.001). There was a significant relationship between increased LNR and lower BMI (P = 0.022) and lymphatic invasion (p = 0.029). In contrast, lymph node retrieval was not associated with mGPS (p = 0.366), NLR (p = 0.523), PLR (P = 0.180) or LMR (p = 0.571). Similarly, LNR was not associated with mGPS (p = 0.313), NLR (p = 0.362), PLR (p = 0.592) or LMR (p = 0.263). Conclusions: The SIR as measured by a number of validated prognostic scores was not associated with either lymph node retrieval or positivity in patients undergoing elective surgery for colon cancer.