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

Abstract
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