A Study of the Oncological Characteristics Affecting the Growth Patterns of the Gastric Cancer

ABSTRACT

PURPOSE: In general, the depth of tumor invasion correlates with lymph node metastasis in gastric cancer, but some cases show a discrepancy between the tumor depth and nodal status. Therefore, this study was designed to investigate the factors affecting tumor growth patterns including the depth of invasion and lymph node metastasis. METHODS: The clinico-pathological characteristics of 1048 gastric cancer, from 1993 to 1999, were investigated. These cancer cases were divided into three groups the early gastric cancer with lymph node metastasis (EP), the serosa infiltrated advanced cancer with no lymph node metastasis (SN), and the serosa infiltrated advanced gastric cancer with lymph node metastasis (SP) groups. The expression status of the proteins related with tumor growth, including matrix metalloproteinase-2 and 9 (MMP-2 and MMP-9), VEGF, nm23 and p53, were compared using immunohistochemical stain, p53 gene mutation, Microsatellite instability (MSI) and Loss of heterozygosity (LOH). RESULTS: There were 35 (3.4%) of the total cases in the EP group, and 10.1% in Early gatric cancer cases. The female ratio in the EP group was higher than in the SN group but this was not statistically significant. The most common gross types in the EP and SN groups were IIc and Borrmann type III, respectively, and the mean tumor size was largest in the SN group. The cell differentiation of the SN group was better than that in the EP group (68.6 vs. 41.2%). The levels of MMP-2 and -9 were higher in the SN and SP groups than those in the EP group. However, the levels of VEGF and nm23 between the groups were no different. The EP group had the highest degree of p53 mutation. There was no difference in the MSI and LOH expression status between the groups. CONCLUSION: There were some different growth patterns in the gastric cancers between the lymph node metastasis dominant (EP) and depth of infiltration dominant (SN) groups. MMP-2 and -9, tumor differentiation and mutated p53 gene exon may correlated with the tumor growth pattern. Further study is suggested to find the difference between the EP and SN groups, which could provide information on which factors determine nodal metastasis or the depth of a infiltration dominant growth pattern.