Effect of number of dissected lymph nodes on prognosis of patients with stage II and III colorectal cancer

Abstract

Aim: There is a correlation between the number of resected lymph nodes (LNs) and survival as well as staging in patients with colorectal cancer (CRC). This cohort discussed the effect of the number of dissected LNs on the prognosis [survival, disease-free survival (DFS)] of patients with stage II and III CRC. Methods: In this historical prospective cohort study, the records of 946 patients with CRC operated in the Seyyed-Al-Shohada hospital in Isfahan from 1998 to 2014 were enrolled. Then the impact of LNs on the overall survival (OS) and DFS were analyzed. Results: The number of removed LNs was higher among males [mean difference = 1.38, t (944) = 2.232, P-value = 0.02]. The median of the DFS for the patients with 1 to 20 LN removal was 104 months [95% confidence interval (CI): 90.97–117.03], while this number for the patients with more than 20 nodes was 166 months (95% CI: 140.41–191.58). DFS between two groups of CRCs, LN removal 1–20, and greater than 20. Age and number of LN removal were significant predictors of the DFS. There was a strong and statistically significant correlation between DFS and OS among CRC patients. Conclusions: This study shows that if the number of resected LNs in patients with CRC is more than 20, it will increase in DFS and OS.