Positive lymph node retrieval ratio optimises patient staging in colorectal cancer

Area of Science:

• Oncology
• Surgical Pathology
• Cancer Staging

Background:

• Accurate staging is crucial for predicting long-term survival in colorectal cancer patients.
• Conventional TNM staging may not fully capture prognostic information, necessitating exploration of alternative lymph node (LN) parameters.

Purpose of the Study:

• To compare alternative lymph node (LN) parameters with conventional TNM staging in predicting long-term survival after curative resection for colorectal cancer.
• To evaluate the prognostic value of the positive lymph node ratio (pLNR) in colorectal cancer.

Main Methods:

• A retrospective analysis of 295 colorectal cancer patients who underwent curative resection between 2001 and 2004.
• Collected data included age, sex, primary tumor site, TNM stage, and adjuvant therapy.
• Analyzed various LN parameters: total LN retrieved, adequate LN retrieval (>=12), inadequate LN retrieval (<12), total negative LN, total positive LN, and the positive lymph node ratio (pLNR).
• Performed univariate and multivariate survival analyses.

Main Results:

• Inadequate lymph node retrieval did not significantly impact long-term survival across T and N stages.
• The positive lymph node ratio (pLNR) emerged as an independent predictor of overall survival in both colon and rectal cancers.
• Multivariate analysis showed a significant hazard ratio for pLNR (HR 11.65 for colon, HR 13.40 for rectal cancer).
• The pLNR effectively stratified patients into four distinct prognostic groups.

Conclusions:

• The positive lymph node ratio (pLNR) significantly improves patient stratification in colorectal cancer.
• pLNR is a more powerful prognostic indicator than conventional staging methods.
• The study recommends considering pLNR for incorporation into future colorectal cancer staging systems.