Risk factors for lymph node metastasis in p/ypT1-2 rectal cancer

Area of Science:

• Oncology
• Surgical Oncology
• Gastrointestinal Cancer Research

Background:

• Investigating risk factors for lymph node metastasis in rectal cancer is crucial for treatment planning.
• Understanding differences in metastasis predictors based on neoadjuvant chemoradiotherapy (CRT) status is essential.

Purpose of the Study:

• To identify and compare independent risk factors for lymph node metastasis in rectal cancer patients who did and did not receive neoadjuvant chemoradiotherapy.
• To elucidate the specific role of venous invasion in lymph node metastasis within the CRT group.

Main Methods:

• Retrospective analysis of 1354 rectal cancer patients undergoing curative surgery.
• Patients were categorized into Non-CRT (n=921) and CRT (n=433) groups based on preoperative treatment.
• Statistical analysis to identify independent predictors of lymph node metastasis in each group.

Main Results:

• Lymph node metastasis rates were 20.4% in Non-CRT and 17.6% in CRT groups.
• Independent predictors in Non-CRT: lymphatic invasion, tumor budding, and pT2 stage.
• Independent predictors in CRT: lymphatic invasion and venous invasion, with venous invasion showing a strong association (OR 12.102).

Conclusions:

• Risk factors for lymph node metastasis in rectal cancer differ significantly based on neoadjuvant chemoradiotherapy status.
• Venous invasion is a critical determinant of lymph node metastasis in patients treated with CRT.
• Identifying these distinct risk factors can refine prognostic assessments and treatment strategies.