Mucosal high apoptotic activity and low p21 super(WAF1-CIP1) expression and submucosal low proliferative activity in superficially spreading early gastric cancers: Comparison with the penetrating growth type

• Published in: Pathology international 2003-02, Vol.53 (2), p.81-89
• Main Authors: Ichinoe, Masaaki, Mitomi, Hiroyuki, Kikuchi, Shiro, Tanabe, Satoshi, Akino, Fumiyuki, Okayasu, Isao
• Format: Article
• Language: English
• ISSN: 1320-5463; 1440-1827
• DOI: 10.1046/j.1440-1827.2003.01438.x

In order to investigate cell kinetics and cell cycle regulator protein expression with reference to the growth pattern of early gastric carcinomas (EGCs), we evaluated a total of 240 EGCs with submucosal invasion clinicopathologically and 106 submucosal invasive lesions immunohistochemically. The incidence of lymph node metastasis was relatively high (36.4%) in the superficially spreading growth (SUP) type tumors whereas the penetrating growth (PEN) type had a low incidence (5.7%, P < 0.001) and correlated with submucosal tumor size. Ki67 labeling was lower in submucosal areas of the SUP-type tumors (median, 37.3%) than the PEN-type tumors (51.0%, P < 0.001). ssDNA labeling in the lamina propria, indicative of apoptotic activity, was higher in the SUP-type tumors (0.55%) than in PEN-type (0.30%, P < 0.01) lesions. The expression of cell cycle regulator p21 super(WAF1-CIP1) was lower in the SUP-type tumors (lamina propria 15.6%, submucosa 2.6%) than in PEN-type tumors (lamina propria 26.5%, submucosa 4.4%, P < 0.05-0.001). In conclusion, differences in cell kinetics and p21 super(WAF1-CIP1) expression might influence the growth pattern of EGCs. The SUP-type EGC, characterized by high apoptotic in the lamina propria and low proliferative activities in the submucosa, is associated with frequent lymph node metastasis, suggesting a strong correlation between tumor size in the submucosa and metastatic potential.