Clinicopathological Factors Influencing Lymph Node Yield in Colorectal Cancer: A Retrospective Study

Area of Science:

• Oncology
• Pathology
• Surgical Oncology

Background:

• Accurate staging of colorectal cancer is crucial for effective treatment planning and prognosis.
• The American Joint Committee on Cancer recommends a minimum of 12 lymph nodes (LNs) for accurate staging.
• Many colorectal resections fall short of this minimum LN yield, potentially compromising staging accuracy.

Purpose of the Study:

• To identify factors influencing lymph node (LN) retrieval in colorectal specimens.
• To analyze the impact of patient and tumor characteristics on the number of LNs examined.
• To evaluate the prognostic significance of achieving the minimum LN count for patient survival.

Main Methods:

• Retrospective analysis of 2319 curatively resected colorectal cancer patients (1993-2017).
• Inclusion of colon cancer, rectal cancer, and rectal cancer patients who received neoadjuvant therapy.
• Uni- and multivariate analyses to determine factors affecting LN yield, followed by survival analysis.

Main Results:

• Mean LN counts varied by tumor location: right colon (24.08), left colon (20.34), and rectum (15.33).
• Adequate LN yield (≥12) was achieved in 86.9% of colon cancer and 63% of rectal cancer cases.
• Factors significantly affecting LN retrieval included tumor location (right colon), larger tumor size, specimen length, pT3-T4 disease, and female sex.

Conclusions:

• Multiple patient and tumor factors influence lymph node yield in colorectal specimens.
• Achieving a minimum of 12 lymph nodes is essential for reliable staging.
• A higher lymph node count (≥12) was associated with significantly better long-term survival in colon cancer patients.