The Number of Natural Killer Cells in the Largest Diameter Lymph Nodes Is Associated with the Number of Retrieved Lymph Nodes and Lymph Node Size, and Is an Independent Prognostic Factor in Patients with Stage II Colon Cancer.

Objective: We previously reported that the largest diameter of retrieved lymph nodes (LNs) correlates with the number of LNs and is a prognostic factor in stage II colon cancer. We examine whether T, B, and natural killer (NK) cells in LNs are related to the number of LNs and survival.

Methods: The subjects comprised 320 patients with stage II colon cancer. An LN with the largest diameter was selected in each patient. The positive area ratios of cells that stained for CD3 and CD20, and the numbers of CD56-positive cells were measured.

Results: The CD3-positive area ratio was 0.39 ± 0.08 and CD20-positive area ratio was 0.42 ± 0.10. The mean number of CD56-positive cells was 19.3 ± 22.7. The area ratios of B cells and T cells and the number of NK cells were significantly related to the sizes of the largest diameter LNs. The number of NK cells significantly correlated with the number of LNs and was an independent prognostic factor. On multivariate analysis, pathological T stage (T4 or T3; HR 4.71; p < 0.001) and the number of CD56-positive cells (high or low; HR 0.22; p < 0.001) were found to be independent prognostic factors.

Conclusions: The number of NK cells in the largest diameter LNs can most likely be used as a predictor of recurrence.