The impact of lymph node ratio (LNR) on survival in patients with colorectal cancer

Abstract

15053 Background: The reason for improved survival in colorectal cancer subjects with increased numbers of lymph nodes (LN) removed is controversial. An inverse relationship has been shown between lymph node ratio (LNR, ratio of positive to total number of LN removed) and survival in subjects with non-metastatic disease when at least 10 lymph nodes are sampled. To assess the effect on those with less than 10 nodes removed, a retrospective study of subjects treated at the Central Arkansas Veterans Healthcare System (CAVHS) was conducted. Methods: Data on subjects with a diagnosis of colorectal cancer attending CAVHS from January 1991 to October 2005 was obtained from the tumor registry. The number of LNs dissected, the number of positive and negative LNs, LNR, treatment and overall survival was analyzed. The number of resected nodes was grouped as follows: none (LNG0, n=150), 1–10 (LNG1, n=320), 11–14 (LNG2, n=35), and >14 (LNG3, n=26). LNR groups were analyzed as follows: LNR <0.05 (n=275), 0.05–0.19 (n=1...