Adequate lymph node recovery improves survival in colorectal cancer patients.

Introduction: Current recommendations suggest recovery of 12 lymph nodes during surgical resection for colorectal cancer (CRC) for proper staging and prognostication. Adequate lymph node recovery has been associated with improved patient survival, with results inconsistent.

Methods: We examined factors for association with adequate lymph node recovery and used findings to adjust survival analyses to clarify whether adequate lymph node examination is associated with CRC survival or associated with a subset of characteristics that biases lymph node recovery.

Results: In 74% of subjects (1,036/1,397) an adequate number of lymph nodes was examined. A stepwise multivariate regression analysis showed procedure year, cancer stage, tumor size, and age at diagnosis were significantly associated with lymph node recovery. These and other factors associated with survival status were adjusted for in further analyses, revealing no difference in unadjusted overall survival by adequacy of lymph node recovery (HR = 0.90, 95% CI: 0.75-1.08, P = 0.239). However, in adjusted Cox proportional hazards analysis, adequate lymph node recovery was associated with reduced risk for death (HR = 0.71, 95% CI: 0.57-0.89, P = 0.002).

Conclusion: The current recommendation for retrieval and examination of at least 12 lymph nodes is appropriate for proper treatment and prognostication in patients undergoing surgical resection for CRC.