Lymphatic Mapping in Colon Cancer Depending on Injection Time and Tracing Agent: A Systematic Review and...

Area of Science:

• Oncology
• Surgical Pathology
• Medical Imaging

Background:

• Optimized lymph node yield is crucial for colon cancer survival, yet extended lymphadenectomy lacks proven survival benefits.
• Aberrant lymphatic drainage in colon cancer can lead to local recurrence if tumor-draining lymph nodes are not resected.
• Current lymphatic mapping protocols vary, necessitating an assessment of their efficacy in detecting metastatic lymph nodes.

Purpose of the Study:

• To compare the effectiveness of different lymphatic mapping protocols in detecting tumor-draining and potentially metastatic lymph nodes in colon cancer.
• To identify the optimal protocol for lymphatic mapping to improve the detection rate of aberrant lymphatic drainage pathways.

Main Methods:

• A systematic review and meta-analysis adhering to PRISMA guidelines was conducted.
• Included prospective trials with in vivo tracer application, with risk of bias assessed using the QUADAS-2 tool.
• Analyzed traced lymph node rates, total resected lymph nodes, and aberrant drainage detection rates across various protocols.

Main Results:

• Preoperative tracer injection significantly increased traced lymph node rates (30.1%) compared to intraoperative injection (14.1%).
• Preoperative injection also led to a significantly higher detection rate of aberrant lymph nodes (26.3%) versus intraoperative injection (2.5%).
• Indocyanine green was identified as a superior tracer for aberrant drainage detection (OR 0.127, p=0.012).

Conclusions:

• Optimized lymphatic mapping techniques, particularly preoperative tracer injection, significantly enhance the detection of aberrant lymphatic drainage patterns in colon cancer.
• This improved detection enables a more personalized surgical approach, potentially reducing local recurrence rates.
• Further research into specific tracer applications and injection timings can refine surgical strategies for better patient outcomes.