Expression of chymase-positive cells in gastric cancer and its correlation with the angiogenesis.

Background and Objectives Chymase is expressed in mast cells and induces angiogenesis via activation of angiotensin II and matrix metalloproteinase-9. However, it has been unclear whether chymase is involved in the pathophysiology of angiogenesis in gastric cancer. To clarify the contribution of chymase to angiogenesis in gastric cancer, we assessed the relationship between chymase-positive cells and tumor angiogenesis. Methods We evaluated chymase-positive cells and microvessels using anti-human chymase and anti-CD34 antibodies in 168 cases of gastric cancer, respectively. Results Chymase-positive cells in gastric tumor region were significantly higher than the cells in normal region. The number of chymase-positive cells in the undifferentiated type of gastric tumor region was significantly higher than the one in the differentiated type. Specimens from patients with advanced histological stages of disease had more chymase-positive cells than those with early-stage disease. There was a significant positive correlation between chymase-positive cells and microvessels in gastric cancer specimens. Postoperative survival curves revealed that patients with a high number of chymase-positive cells had a poor prognosis. Conclusions These results suggest that accumulation of chymase-positive cells in gastric cancer may lead to an increase of tumor angiogenesis, and may contribute to tumor growth and progression. J. Surg. Oncol. 2006;93:36–42. © 2005 Wiley-Liss, Inc.