Lymph node micrometastases do not predict relapse in stage II colon cancer

Area of Science:

• Oncology
• Gastroenterology
• Surgical Pathology

Background:

• Stage II colonic adenocarcinoma recurrence affects over a third of patients.
• Identifying high-risk patients is crucial for effective adjuvant therapy.
• Prognostic significance of minimal nodal involvement in colon cancer remains unclear.

Purpose of the Study:

• To evaluate the utility of immunohistochemistry in detecting micrometastases in mesenteric lymph nodes of stage II colon cancer patients.
• To determine if nodal micrometastases predict tumor recurrence in stage II colonic adenocarcinoma.

Main Methods:

• Mesenteric lymph nodes from 55 stage II colon cancer patients were re-examined using H&E and keratin immunohistochemistry.
• Lymph nodes from 10 control patients with nonneoplastic disorders were also stained.
• Keratin-positive cells and clusters were quantified and compared between patients with and without tumor relapse.

Main Results:

• Micrometastases were detected in 67% of relapsed patients and 84% of non-relapsed patients.
• No significant difference in the mean number of positive nodes or keratin-positive cells/clusters was observed between the relapse and no evidence of disease groups.
• No keratin-positive cells were found in control patient lymph nodes.

Conclusions:

• Immunohistochemical staining frequently detects micrometastases in mesenteric lymph nodes of stage II colon cancer patients.
• Nodal micrometastases identified by keratin staining are not prognostic for identifying stage II colonic adenocarcinoma patients at higher risk of relapse.