[Treatment of lymph node metastasis from the viewpoint of surgical oncology]

We have investigated methods to predict lymph node metastasis in early gastric cancer. First, the efficacy of fluorescence in situ hybridization (FISH) using the dual-color method was evaluated as a potential marker of lymph node metastasis in 20 early gastric cancers. A significant increase in the fraction of cells with a decrease in p53 was observed in early gastric cancer compared with normal tissues. More importantly, a significant increase in the fraction of cells with p53 deletion was observed in patients with lymph node metastasis. The predictive accuracy was 45%. Second, the relationship between the degree of expression of biological markers and lymph node metastasis was examined. High expression of p27 and cyclin E had a strong correlation with lymph node metastasis. Moreover, all patients with combined high expression of p27, cyclin E, and matrix metalloproteinase-9 had lymph node metastasis. However, these represented only 21% of cases with lymph node metastasis. Difficulty in the clinical use of these biological markers to detect lymph node metastasis depends on the feedback mechanism of cell cycle regulators or heterogeneity of the lesion. These problems should be resolved in the near feature.