Prognostic value of the lymph node ratio after resection of periampullary carcinomas

BackgroundData have indicated that the lymph node ratio (LNR) may be a better prognostic indicator than lymph node status in pancreatic cancer. ObjectivesTo analyse the value of the LNR in patients undergoing resection for periampullary carcinomas. MethodsA cut off value of 0.2 was assigned to the LNR in accordance with published studies. The impact of histopathological factors including a LNR was analysed using Kaplan-Meier and Cox regression methods. ResultsIn total, 551 patients undergoing a resection (January 2000 to December 2010) were analysed. The median lymph node yield was 15, and 198 (34%) patients had a LNR > 0.2. In patients with a LNR of > 0.2, the median overall survival (OS) was 18 versus 33 months in patients with an LNR < 0.2 (P < 0.001). Univariate analysis demonstrated a LNR > 0.2, T and N stage, vascular or perineural invasion, grade and resection margin status to be significantly associated with OS. On multivariate analysis, only a LNR > 0.2, vascular or perineural invasion and margin positivity remained significant. In N1 disease, a LNR was able to distinguish survival in patients with a similar lymph node burden, and correlated with more aggressive tumour pathological variables. ConclusionA LNR > 0.2, and not lymph note status, is an independent prognostic factor for OS indicating the LNR should be utilized in outcome stratification.