Correlation of microvessel density with histopathological parameters of carcinoma breast

Microvessel density (MVD) is a surrogate measure of tumour angiogenesis, and is well known for over two decades to identify individuals with a high risk of recurrence with greater prevision than traditional markers. This study aims to assess the utility of MVD and its correlation with the Nottingham Prognostic Index (NPI) and other routine histopathological parameters in carcinoma breast.

This two year retrospective, cross-sectional and analytical study evaluated 143 women with breast cancer presenting to rural tertiary hospital in central India. These women were graded histopathologically, the immunophenotype was determined using ER (estrogen receptor), PR (progesterone receptor), Her2 neu (human epidermal growth factor receptor 2 neu) and Ki-67 proliferation index (Kiel-67) immunohistochemical markers and anti-CD34 antibody to stain the endothelial cell clusters displaying the microvessels. The NPI was generated for each participant based on the tumour size, histologic grade and involvement of lymph node. The parameters were compared with the CD34 scores. Differential and inferential statistics, including the independent t test, analysis of variance, Pearson's correlation coefficient, Spearman's rank correlation coefficient and point biserial correlation coefficient, were used for statistical analysis.

This study showed that CD34 values ranged from 6-36 microvessels/hpf, with 24.16±6.77 microvessels/hpf as the mean. The mean microvessel counts showed a significant positive correlation with the Bloom-Richardson histological grade, vascular invasion, LN (lymph node) positivity and NPI. However, there was no significant correlation of CD34 values with the participant's age, tumour size neither any significant association of CD34 values with the individual's immunophenotype.

A positive linear correlation of the microvessel counts and the NPI scores suggest that with an increase in tumour angiogenesis, there was increased proliferative potential. Based on the significant correlation between the microvessel counts and the vascular invasion of the tumour masses in this study, it can be assumed that there will be vascular invasion if the microvessel count is higher and vice-versa. Although it is established that angiogenesis and neovascularization are required for the expansion of the solid tumour tissue, the heterogeneous nature of this entity makes it difficult for obtaining a linear correlation. Hence, it is suggested that though neovascularization permits advanced tumour spread it, however, does not guarantee it.