Objectives: To study the effect of ectopic HCG on microvessel density in gastric carcinoma using immunohistochemical staining with anti-beta-HCG polyclonal antibody and anti-factor VIII related antigen(FVIII RAg)antibody.
Methods: A total of 40 specimens resected from patients with gastric carcinoma was investigated by immunohistochemical staining with a anti-beta-HCG polyclonal antibody and a monoclonal antibody against FVIII RAg. The expression of beta-HCG and the microvessel density(the average number of microvessel in three areas of highest vascular density at 400 x magnification) in various regions of the histologic specimens were studied.
Results: Fifteen (37.5%) of the 40 gastric carcinomas was positive for beta-HCG protein in tumor tissue. beta-HCG protein was negative in the tumor-adjacent and in normal tissue. The mean microvessel density was 27.4 +/- 7.1 in the tumor, 11.9 +/- 5.4 in tumor-adjacent and 4.8 +/- 1.5 in normal tissues (P < 0.05-0.01). There was a close correlation with beta-HCG positivity and microvessel density (MVD). There was no correlation between the degree of tumor cell differentiation and beta-HCG expression, nor was a correlation between it and MVD. High expression level of beta-HCG and MVD was significantly associated with hematogenous metastases.
Conclusion: Ectopic HCG expression may have angiogenic effect which, in turn, may facilitate hematogenous dissemination of gastric cancer.