Different types of tumor vessels in breast cancer: morphology and clinical value

Angiogenesis is a key factor of tumor progression. Considering, that the tumor vessels are heterogeneous and differ in morphology and clinical significance, the purpose of this research was to study of the morphological features of tumor vessels and their relationship with the clinical characteristics and morphological features of breast cancer (BC). In this pilot study the tumor samples received from 59 patients with T1-T2 stages of ductal invasive carcinomas were included. The sections were stained with hematoxylin and eosin and immunohistochemically using antibodies to CD34. The morphological features and the number of different types of tumor vessels were assessed microscopically and were compared with grade, lymph node metastasis, hormone receptors, HER2/neu status and with the presence of tumor emboli in vessels (lymphovascular invasion). We identified the following types of tumor vessels in BC: the normal microvessels, the dilated capillaries of peritumoral stroma, the atypical dilated capillaries and the "cavitary" structures (CS) type-1 and type-2 relating to the "cavitary" type of angiogenesis that was described by us earlier. The number of dilated capillaries correlated with CS type-1 (p = 0.003), CS type-2 (p = 0.002), atypical dilated capillaries (p = 0.0008) and with lymphovascular invasion (p = 0.005); the presence of atypical dilated capillaries-with CS type-1 (p < 0.00001), CS type-2 (p = 0.00004), lymphovascular invasion (p = 0.0002) and with the tumor grade (p = 0.003); the number of CS type-1-with estrogen receptor (p = 0.002) and progesterone receptor (p = 0.002) status and with lymphovascular invasion (p = 0.004); the presence of CS type-2-with positive Her2/new status (p = 0.0002) and lymphovascular invasion (p = 0.01). The density of normal microvessels was not associated with other types of tumor vessels and with clinical characteristics of BC. These data indicate that varied types of tumor vessels are associated with different morphological characteristics of BC, such as hormone receptors and HER2/neu status, lymphovascular invasion. We believe that the atypical dilated capillaries are related to the "cavitary" type of angiogenesis. The strong correlations of lymphovascular invasion with CS type-1 and atypical dilated capillaries testify that the "cavitary" type of angiogenesis may play a significant role in the formation of tumor emboli in the vessels.