Lymphatic and blood vessel morphometry in invasive breast carcinomas: relation with proliferation and VEGF-C and -D proteins expression.

Abstract

INTRODUCTION: The aim of the present study was to investigate the distribution of both lymphatics and blood microvessels in invasive breast carcinomas and the clinicopathological and prognostic significance of their density and size related parameters as well as their correlation with the proliferative potential of the tumor and VEGF-C and -D expression. METHODS: Both single and double immunohistochemistry were applied on a series of 146 paraffin-embedded breast tissue specimens to detect VEGF-C and -D as well as lymphatics and blood microvessels, respectively. Computer-assisted morphometry was performed to evaluate the blood and lymphatic vessel density (BVD and LVD respectively) as well as various vascular size related parameters. RESULTS: Lymphatics were detected within the stroma at the tumor border, while blood vessels were located in both the interior of the tumor mass and peritumor stroma. BV major axis, minor axis and perimeter inversely correlated with ER (p=0.011, p=0.023 and p=0.008 respectively), while LV major axis, minor axis and the perimeter inversely correlated with tumor nuclear grade (p=0.045, p=0.037 and p=0.032 respectively) and topoisomerase IIalpha (p=0.015, p=0.024 and p=0.045 respectively). The same LV parameters were found to positively correlate with cancerous VEGF-C (p<0.0001, p=0.092 and p=0.012 respectively) and VEGF-D in the stromal fibroblasts surrounding neoplastic cells (p=0.011, p=0.041 and p=0.026 respectively). High BVD exerted an unfavorable impact on both disease-free (p=0.021) and overall survival (p=0.031) of the patients. High LVD correlated with poor disease-free and overall survival only in the subgroup of patients with ER-negative tumors (p=0.056 and p=0.0312 respectively). CONCLUSION: These findings, for the first time, correlate lymphatic size with tumors of limited proliferative potential and higher nuclear differentiation. Moreover, they suggest that VEGF-C and -D expression influence lymphatic size rather than being involved in the increase of lymphatic vessel number.