Prognostic Importance of the Lymph Node Ratio in Stage Iii Colorectal Cancers

Abstract

Objective: Colorectal cancers (CRCs) are among the most common cancers all over the world with a high mortality rate. Many prognostic factors have been identified for these cancers, one of which is the lymph node ratio (LNR). The purpose of this study was to reveal the prognostic importance of the LNR in stage III CRCs. 
 Material and Methods:The records of stage III colorectal patients who received adjuvant chemotherapy between January 1998 and May 2014 were examined retrospectively. Similar to the literature, the patients were divided into three groups according to their LNRs. Those with a ratio of 0–0.20 were in the 1st group, with 0.21–0.50 were in the 2nd group, and with 0.51–1 were in the 3rd group. Demographic characteristics of the patients, number of positive and total lymph nodes removed, lymph node positivity rate, presence of free tumor nodules, and survival were evaluated.
 Results: A total of 263 patients were included in the study. While 163 (61.9%) of the patients were male, the median age was 62 (min: 25–max: 85). The mean number of lymph nodes removed was 17.46 (±11.55), and the mean number of positive lymph nodes was 3.48 (±5.13). The mean duration of disease-free survival (DFS) was 65.2 (±46.07) months (min = 6, max = 223). The mean overall survival time (OS) was 70.9 (±44.4) months (min = 6, max = 223). In univariate analysis, it was observed that as the LNR increased, recurrence and mortality increased statistically significantly (P < 0.001). According to the results of multivariate analysis, the relationship of DFS and OS with the LNR groups was statistically significant (P = 0.030 and P = 0.019, respectively).
 Conclusion: The LNR in operated stage III CRC is an effective prognostic factor on DFS and OS