Histological characteristics of tumors in blood vessels play an important role in tumor progression of invasive ductal carcinoma of the breast.

Whether the characteristics of tumor cells in blood vessels play an important role in the tumor progression of invasive ductal carcinoma (IDC) of the breast is not known. The purpose of this study was to investigate the significance of the characteristics of tumor cells in blood vessels in relation to tumor progression in 247 IDC patients with blood vessel invasion, in comparison with well-known histological parameters. Blood vessel tumor embolus dimensions were measured. Nuclear atypia, numbers of mitotic and apoptotic figures, and fibrosis grade of tumor cells in blood vessels were assessed. Cox proportional hazard multivariate analyses showed that >2 mitotic figures in blood vessel tumors significantly increased the hazard rates (HRs) of disease-free survival (P=0.002) and initial distant organ metastasis-free survival (IDOMS) in node-negative IDCs (P=0.005), and the HRs of disease-free survival (DFS, P=0.007) and IDOMS (P=0.015) in node-positive IDCs. Apoptotic figures >2 in blood vessel tumor emboli significantly increased the HR of overall survival (P=0.007) in node-positive IDCs. The present study showed the number of mitotic and apoptotic figures in tumor cells in the blood vessels to play a very important role in the tumor progression of IDCs.