Lymphadenectomy in colorectal cancer

Summary Background Lymphadenectomy in colorectal cancer surgery is one of the most important components of oncological surgery and is the foundation for patients’ healing. For generations, a debate has been ongoing in the literature about the optimal extent of lymphadenectomy. We here present a review of the literature concerning the impact of lymph node metastases, the influence of resection margins and the extent of lymphadenectomy in colorectal cancer surgery. Methods A narrative review of the literature was conducted focusing on oncological principles of colorectal cancer surgery, including lymph node metastases, lymph node yield, lymph node ratio, resection margins, vascular ligation and mesocolic/mesorectal excision techniques. Results The presence of lymph node metastases, the total number of harvested lymph nodes and the lymph node ratio are major prognostic factors that affect survival outcomes in colorectal cancer patients. Adequate oncological resection requires en bloc removal of the tumour-bearing bowel segment with proximal and distal margins of approximately 5–10 cm. This should be combined with central ligation of the feeding vessels and complete excision of the lymph node-bearing mesocolon or mesorectum. Dissection along the embryological planes facilitates complete mesocolic excision in colon cancer and total mesorectal excision in rectal cancer, which are both associated with improved oncological outcomes and reduced local recurrences. The extent of central lymphadenectomy along the superior and inferior mesenteric vessels must balance oncological radicality with the potential risk of increased morbidity and postoperative complications associated with more extensive resections. Conclusion Optimal lymphadenectomy in colorectal cancer surgery requires a balance between radical oncological clearance and surgical safety. Adequate lymph node harvest, central vascular ligation and precise dissection along embryological planes remain essential principles for improving staging accuracy and patient survival while minimising operative morbidity.