Tumor Deposits as an Adverse Prognostic Indicator in Stage III Colon Cancer: A Multicenter Database Study.

Area of Science:

• Oncology
• Cancer Staging
• Colorectal Cancer Research

Background:

• Current American Joint Committee on Cancer staging classifies tumor deposits (TDs) as N1c.
• Nodal staging (N1a/b, N2a/b) currently prioritizes lymph node metastases (LNMs) over TDs.

Purpose of the Study:

• To investigate the oncological impact of tumor deposits (TDs) in colon cancer.
• To propose modifications to the colon cancer staging system for improved accuracy.

Main Methods:

• Analysis of 4212 patients from Seoul Colorectal Group and 93,057 from SEER database.
• Classification based on lymph node metastases (LNs) and presence of TDs.

Main Results:

• TDs associated with left colon cancer, higher T category, and vascular/perineural invasion.
• TD-positive patients showed significantly higher recurrence rates (23.1% vs 7.5%) and worse overall survival (OS) and recurrence-free survival.
• Survival outcomes for TD-positive patients mirrored those of TD-negative patients with higher nodal burden.

Conclusions:

• Tumor deposits are significant negative prognostic factors impacting colon cancer survival.
• Integrating TDs into nodal classification beyond N1c may improve staging accuracy.
• Reclassifying TD-positive N1a or N1b cases as N2 could better reflect patient prognosis.