Study of angiogenesis in invasive breast carcinoma by morphometry and immunohistochemistry

Breast cancer is the leading cause of cancer-related deaths in Asia and is emerging as the commonest female malignancy. Angiogenesis or neovascularization is important for the growth and spread of malignant tumors, and quantitative assessment of angiogenesis may prove valuable in prognostication. This study was undertaken to quantify and explore angiogenesis with immunohistochemistry with CD 34, CD 105, and vascular endothelial growth factor (VEGF), as well as morphometric analysis and correlate with the grades of the invasive breast carcinoma.

Angiogenesis was assessed by morphometry and immunohistochemistry. Seventy cases of invasive ductal carcinoma (IDC) and twenty-five benign cases as controls were included in the study. Morphometry was performed on the CD34 and CD105 (Endoglin) stained representative histologic sections with the use of a computerized digital photomicrograph system using image analyzing software. Morphometric analysis and evaluation of vascular parameters, i.e. microvessel density (MVD), microvessel caliber (VC), and total microvessel boundary density (TVBD), were calculated. Semiquantitative assessment of angiogenesis of VEGF-stained sections was done by scoring. Immunohistochemical staining was correlated with the histological grade of the tumors. MVD, mean VC, TVBD with their mean values, SD, and range were calculated using Statistical Package for The Social Sciences (Version 20). One-way analysis of variance (ANOVA) with Tukey HSD was performed to assess the difference of the parameters for the groups. Spearman rank correlation coefficients ρ were calculated.

The vascular parameters were significantly more in malignant lesions as compared to benign lesions and showed differences with increasing grade. Grades of breast carcinoma showed a mild positive correlation with VEGF (ρ = 0.467), MVD-CD34 (ρ = 0.422) and VC-CD34 (ρ = 0.482); and moderate positive correlation with TVBD-CD34 (ρ = 0.615), VC-CD105 (ρ = 0.527), and TVBD-CD105 (ρ = 0.354). When these parameters were compared with each other for all four groups, VEGF showed a mild positive correlation with MVD-CD34 (ρ = 0.295), TVBD-CD34 (ρ = 0.339), and TVBD-CD105 ((ρ = 0.277). MVD-CD105 showed a mild positive correlation with MVD-CD34 TVBD-CD105 also showed a strong positive correlation with MVD-CD34. VC-CD105 showed a moderate positive correlation with VC-CD34. CD 105 stained fewer but larger caliber vessels.

In this study, vascular parameters showed significant differences in three grades of IDC with CD34. Differences were seen in vascular parameters stained with CD105 in three grades of IDC. Expression of VEGF also showed significant differences with positive correlations in the three grades of IDC. CD34 highlighted both old and newly formed microvessels. CD 105 stained fewer but larger caliber microvessels. VC-CD105 can be an extremely useful adjunct along with VEGF and CD34 to study angiogenesis of vessels in IDC.