Contributing factors on lymph node yield after surgery for mid-low rectal cancer

Area of Science:

• Colorectal surgery
• Oncology
• Surgical pathology

Background:

• Accurate lymph node staging is crucial for rectal cancer treatment.
• Preoperative chemoradiotherapy (CCRT) is a standard treatment for locally advanced rectal cancer.
• The impact of CCR on lymph node retrieval requires further investigation.

Purpose of the Study:

• To identify factors influencing lymph node status in mid-low rectal cancer.
• To determine the effect of preoperative CCRT on lymph node yield.
• To evaluate the adequacy of lymph node harvest after neoadjuvant therapy.

Main Methods:

• Retrospective analysis of 277 mid-low rectal cancer patients (1998-2007).
• Comparison of lymph node retrieval between patients who received preoperative CCRT (n=82) and those who did not.
• Multivariate analysis to identify independent predictors of lymph node yield.

Main Results:

• A mean of 13.12 lymph nodes was retrieved.
• Preoperative CCRT, tumor stage, and lymphovascular invasion significantly influenced lymph node retrieval.
• Multivariate analysis revealed that CCRT was independently associated with fewer retrieved lymph nodes (p<0.001).
• Node-negative patients (ypN0) in the CCRT group had significantly fewer lymph nodes harvested compared to node-positive patients (ypN1-2) (p=0.027).

Conclusions:

• Preoperative CCRT is an independent risk factor for inadequate lymph node harvest in rectal cancer.
• Node-negative rectal cancer patients treated with preoperative CCRT are at higher risk for fewer lymph nodes retrieved.
• Optimizing surgical technique and lymph node dissection is essential in patients undergoing preoperative CCRT.