Examining the relationship between lymph node harvest and survival in patients undergoing colectomy for colon adenocarcinoma.

Background: Current standards for lymph node harvest in colorectal cancer surgery may be inadequate. Higher lymph node yield may improve survival, but the number of lymph nodes needed to optimize survival is unknown. The objective of this study was to examine the relationship between lymph node yield and overall survival in patients undergoing colectomy for nonmetastatic colon adenocarcinoma.

Methods: The 2010 to 2014 National Cancer Database was queried for patients undergoing colectomy for nonmetastatic colon adenocarcinoma. Adjusted restricted cubic splines were used to model the nonlinear relationship between lymph node harvest and overall survival. Cox proportional hazard determined independent predictors of overall survival.

Results: A total of 261,423 patients were included. Restricted cubic splines demonstrated that the adjusted improvements in overall survival stabilized after 24 nodes. Patients were divided into: <12, 12 to 23, and ≥24 nodes. On survival analysis, patients with ≥24 nodes had better survival across all N stages compared to other groups (P < .001). Lymph node harvest ≥24 nodes was independently associated with improved overall survival compared to 12 to 23 nodes (hazard ratio 0.82; 95% confidence interval, 0.80-0.85).

Conclusion: Lymph node harvest ≥24 nodes is associated with improved survival in colorectal cancer patients. These data may provide indirect evidence for a more extensive lymphadenectomy for colon cancer.