Abstract 786: Vascularity and vascular maturity in breast cancer: a comparative analysis of the different molecular subtypes
Authors: Ayoub Nehad M. , Husban Ahmed Y. Al , Husban Hussein M. Al , Khatib Abdul Rahman N. Al , Al-Mesleh Alaa O. , Al-Majali Ekhlas A. 
Published: July 2017

Currently, angiogenesis inhibitors lack considerable activity and did not result in survival

advantage in breast cancer. The goal of this study is to evaluate vasculature in terms of

vascularity and vascular maturity among breast cancer subtypes. Archived tumor

samples for breast cancer patients were retrieved from Pathology Department at Royal

Medical Services in Jordan. Tissue sections were stained for the expression of

basement membrane laminin using immunohistochemical analysis. Endothelial cell and

pericyte were identified and counted based on the shape of the nuclei as visualized with

DAPI stain. Demographic, clinical, and pathological data were retrieved from patient

medical records at time of diagnosis. Vascularity was obtained by counting the number

of blood vessels and maturity of blood vessels is represented by the ratio of the average

number of endothelial cell to average number of pericytes. A total of 60 patients were

enrolled in this study in which 34 patients (56.7%) have hormone-dependent disease, 14

patients (23.3%) determined to have HER2-positive disease, and 12 cases (20.0%) were

classified as triple-negative. Results showed a significant difference for the mean

number of blood vessels (p=0.008) and endothelial cell to pericyte ratio (p=0.000)

among the different molecular subtypes of breast cancer. Post hoc analysis indicated

statistically significant difference in mean number of blood vessels between hormone-

dependent and HER2-positive tumors (p=0.015). In addition, ratio of endothelial cells to

pericytes was significantly different between hormone-dependent cases and each of

HER2-positive and triple-negative cases (p=0.000 and 0.014, respectively). Size of

tumor was significantly correlated to endothelial cell to pericyte ratio for the population

examined (r=0.345, p=0.007). A significant correlation was found between the number of

blood vessels and number of involved lymph nodes among all patients (r=0.271,

p=0.038). Independent samples t–test analysis comparing mean number of blood

vessels and endothelial to pericyte ratio according to hormone receptor status showed

significant difference between hormone receptor negative and positive cases for both

estrogen and progesterone receptors (p&lt;0.05). No significant difference was found for

the vascular parameters tested according to tumor stage, grade, and lymphovascular

invasion (p&gt;0.05). Collectively, these findings showed that the degree of tumor

vascularity and vascular maturity are not uniform among breast cancer subtypes.

Vascular maturity was remarkably higher for hormone-dependent breast tumors

compared to both HER2-positive and triple-negative cases. It is critical that a careful

assessment of tumor vasculature is being considered in breast cancer patients in order

to determine responsiveness to chemotherapy and anti-angiogenic treatment among the

different molecular subtypes.

Citation Format: Nehad M. Ayoub, Ahmed Y. Al Husban, Hussein M. Al Husban, Abdul Rahman N. Al Khatib, Alaa O. Al-Mesleh, Ekhlas A. Al-Majali. Vascularity and vascular maturity in breast cancer: a comparative analysis of the different molecular subtypes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 786. doi:10.1158/1538-7445.AM2017-786