Optimal examined lymph node count in node-negative colon cancer should be determined.

Background: We aimed to investigate the association between optimal examined lymph node (ELNs) and overall survival to determine the optimal cutoff point. Methods: Cox models and locally weighted scatterplot smoothing were used to fit hazard ratios and explore an optimal cutoff point based on the Chow test. Results: Overall survival increased significantly with the corresponding increase in the number of ELNs after adjusting for covariates. In Chow's test, the optimal cutoff point for node-negative colon cancer was 15, which was validated in both cohorts after controlling for confounders (Surveillance, Epidemiology, and End Results database: hazard ratio: 0.701, p < 0.001; single-center: HR: 0.563, p = 0.031). Conclusions: We conservatively suggest that the optimal number of ELNs for prognostic stratification is 15 in node-negative colon cancer.

[1]  Xingang Lu,et al.  The re-evaluation of optimal lymph node yield in stage II right-sided colon cancer: is a minimum of 12 lymph nodes adequate? , 2020, International Journal of Colorectal Disease.

[2]  J. Monson,et al.  Examining the relationship between lymph node harvest and survival in patients undergoing colectomy for colon adenocarcinoma. , 2019, Surgery.

[3]  Jeffrey Douaiher,et al.  Predictors of adequate lymph node harvest during colectomy for colon cancer. , 2019, American journal of surgery.

[4]  Ben Huang,et al.  Heterogeneous survival between stage IIA and stage IIIA colon cancer when different numbers of lymph nodes are harvested , 2018, ANZ journal of surgery.

[5]  J. Bleier,et al.  Colorectal Specialization Increases Lymph Node Yield: Evidence from a National Database , 2016, Annals of Surgical Oncology.

[6]  M. Stringer,et al.  Clinico‐pathological factors influencing lymph node yield in colorectal cancer and impact on survival: Analysis of new zealand cancer registry data , 2015, Journal of surgical oncology.

[7]  V. Lemmens,et al.  No change in lymph node positivity rate despite increased lymph node yield and improved survival in colon cancer. , 2014, European journal of cancer.

[8]  J. Begun,et al.  Association between lymph node evaluation for colon cancer and node positivity over the past 20 years. , 2011, JAMA.

[9]  U. Manne,et al.  Evaluation of lymph node numbers for adequate staging of Stage II and III colon cancer , 2011, Journal of hematology & oncology.

[10]  V. Fazio,et al.  Individual Surgeon, Pathologist, and Other Factors Affecting Lymph Node Harvest in Stage II Colon Carcinoma. Is a Minimum of 12 Examined Lymph Nodes Sufficient? , 2011, Annals of Surgical Oncology.

[11]  J. Coebergh,et al.  Pathology practice patterns affect lymph node evaluation and outcome of colon cancer: a population-based study. , 2006, Annals of oncology : official journal of the European Society for Medical Oncology.

[12]  A. Morris,et al.  Lymph node evaluation in colorectal cancer patients: a population-based study. , 2005, Journal of the National Cancer Institute.

[13]  I. Hirata,et al.  Analysis of pathological risk factors for lymph node metastasis of submucosal invasive colon cancer , 2004, Modern Pathology.

[14]  N. Goldstein.  Lymph Node Recoveries From 2427 pT3 Colorectal Resection Specimens Spanning 45 Years: Recommendations for a Minimum Number of Recovered Lymph Nodes Based on Predictive Probabilities , 2002, The American journal of surgical pathology.

[15]  V. Lemmens,et al.  Large variation between hospitals and pathology laboratories in lymph node evaluation in colon cancer and its impact on survival, a nationwide population-based study in the Netherlands. , 2011, Annals of oncology : official journal of the European Society for Medical Oncology.

[16]  J. Hammel,et al.  Does a laparoscopic approach affect the number of lymph nodes harvested during curative surgery for colorectal cancer? , 2009, Surgical Endoscopy.

[17]  L. Sarli,et al.  Number of lymph nodes examined and prognosis of TNM stage II colorectal cancer. , 2005, European journal of cancer.