[Lymph node micrometastases in colorectal cancer].

Area of Science:

• Oncology
• Molecular Diagnostics
• Cancer Research

Context:

• Lymph node (LN) micrometastases in colorectal cancer (CRC) are a long-standing area of research.
• Previous studies indicated immunohistochemistry (IHC) detection of micrometastases had no clinical impact, unlike molecular techniques like RT-PCR.
• Stage II CRC recurrence is linked to factors like T4 invasiveness, vascular invasion, and poor differentiation.

Purpose:

• To evaluate the clinical impact of occult lymph node micrometastases in colorectal cancer.
• To determine the association between molecular detection of micrometastases and prognosis in node-negative CRC patients.
• To advocate for a prospective clinical trial using a simple molecular assay for high-risk stage II CRC patient selection.

Summary:

• Occult lymph node micrometastases detected by molecular methods (e.g., RT-PCR) are associated with a poor prognosis in node-negative colorectal cancer (CRC).
• Despite numerous risk factors identified in stage II CRC, chemotherapy efficacy remains unconfirmed for many patients.
• A meta-analysis confirmed the link between occult disease and poor CRC prognosis, regardless of detection method (IHC or RT-PCR).

Impact:

• Highlights the prognostic significance of occult micrometastases in colorectal cancer.
• Suggests molecular detection methods are superior to IHC for identifying high-risk patients.
• Emphasizes the need for large-scale trials with convenient molecular assays to guide treatment decisions for stage II CRC.