Background: Tumour angiogenesis is essential for the growth, invasion and metastasis of solid tumours. There are several lines of evidence that the mast cells play an important role in tumour angiogenesis.
Aims: The study focused to determine the correlation between the microvessel and mast cell densities, and to evaluate whether tumour angiogenesis and mast cell density could predict recurrence following curative surgery in patients with colorectal carcinomas.
Patients: Microvessel and mast cell densities were investigated in tumour specimens from 60 patients with colorectal carcinoma.
Methods: Microvessels were stained by immunohistochemical method using a monoclonal antibody anti-CD34. The routine Giemsa blue staining method was used to assess the mast cells. Microvessels and mast cells were counted in a x400 field.
Results: The mean microvessel and mast cell counts were higher in patients with recurrence compared with those patients who were disease-free for at least 24 months (p<0.001). The Spearman's correlation coefficient revealed a significant correlation between mast cell and microvessel counts in colorectal carcinomas (r=0.684; p<0.001). Kaplan-Meier plots of survival showed that the high microvessel (>28) and mast cell (>6) counts correlated with a shorter disease-free survival (p=0.0003 and p=0.0013, respectively). Multivariate analysis showed that the depth of penetration (T4 versus T2) (p=0.004), liver metastasis (p=0.04) and microvessel density (p=0.003) were independent predictors of recurrence. In multivariate analysis, mast cell density did not reach significance.
Conclusions: Our results suggest that the microvessel density of the primary tumour may be an important independent predictor of tumour recurrence and time to recurrence in colorectal carcinomas. The significant correlation between mast cell and microvessel counts suggest that the mast cells may have a role in tumour progression via promoting angiogenesis.