Characteristics of tumors in lymph vessels play an important role in the tumor progression of invasive ductal carcinoma of the breast: a prospective study.

It is unknown whether the characteristics of tumor cells in lymph vessels play an important role in the tumor progression of invasive ductal carcinoma (IDC) of the breast. The purpose of this study was to investigate the significance of the characteristics of tumor cells in the lymph vessels in relation to the tumor progression in 393 IDC patients in comparison with well-known histological parameters. The dimensions of lymph vessel tumor emboli were measured, and their structural features, nuclear atypia, and numbers of mitotic and apoptotic figures were also assessed. Multiple regression analysis showed the dimension, the distance, the number of mitotic figures, the number of apoptotic figures, and papillary features of lymph vessel tumor emboli to be significantly associated with the increased number of cells invading the lymph vessels (P < .05). The Cox proportional hazard multivariate analyses showed that more than six apoptotic figures in lymph vessel tumor emboli significantly increased the hazard rates (HRs) of tumor recurrence and death in IDCs without nodal metastasis and that more than four mitotic figures in lymph vessel tumor emboli significantly increased the HRs of tumor recurrence and death in IDCs with nodal metastasis (P < .05). The present study showed that the histological characteristics of tumor cells in lymph vessels play a very important role in the tumor progression of IDCs.