The relationship of tryptase- and chymase-positive mast cells to angiogenesis in stage I non-small cell lung cancer

Objective: There are two types of human mast cells, tryptase-positive mast cells (MCT) and tryptase- and chymase-positive mast cells (MCTC). Although MCT have been reported to be related to the generation of angiogenesis, little is known about the involvement of MCTC in tumor angiogenesis. In this study, to clarify the relationship between MCTC and lung cancer angiogenesis, we evaluated MCTC, MCT, and microvessel counts in normal, border, and central lung cancer regions. Methods: Tumor sections from 32 cases of adenocarcinoma and 13 cases of squamous cell carcinoma were immunostained for chymase to evaluate MCTC, tryptase to evaluate MCT, and CD34 to evaluate microvessel counts. Results: Both MCTC and MCT counts in the border lung cancer region were significantly higher than in the central region, and the MCTC and MCT counts in the central region were significantly higher than those in the normal regions. The microvessel counts in the border region were higher than those in the central region. The ratio of MCTC to MCT in the border region, but not in the central region, was significantly higher than that in the normal region. In the border region, significant correlations not only between MCT and microvessel count, but also between MCTC and microvessel count were observed. In the central region, a significant correlation between MCTC and the microvessel count was observed, but there was no significant correlation between MCT and the microvessel count. Conclusions: These findings suggest that MCTC may be involved in the pathogenesis of angiogenesis in lung cancer.