The role of lymphatic and blood vessel invasion in predicting survival and methods of detection in patients with primary operable breast cancer.

Lymphovascular invasion (LBVI) has long been recognized as an essential step of metastases in patients with cancer. However, the process of invasion into lymphatic and blood vessels is still not well defined in breast cancer. To examine the evidence for LBVI, lymphatic vessel invasion (LVI) and blood vessel invasion (BVI) in predicting survival in patients with primary operable breast cancer, and to evaluate the detection methods of vessel invasion. A systematic review of data published from 1964 to 2012 was undertaken according to a pre-defined protocol. There is robust evidence that general LBVI and LVI are independent prognostic factors of poorer survival. The prognostic role of BVI remains unclear. Most studies detected LBVI using H&E stained sections. The overall weighted average of the LBVI rate using immunostaining was higher (35%) than H&E (24%). The LBVI rate using H&E was variable (9-50%) and less variable using immunostaining (32-41%). The overall weighted average of the LVI rate was similar using H&E and immunostaining (33% vs. 25%). The LVI rate using H&E was variable (10-49%) and less variable using immunostaining (21-42%). The overall weighted average of the BVI rate was similar using H&E and/or classical staining and immunostaining (16% vs. 10%). The BVI rates using H&E and/or classical staining approach (4-46%) and immunostaining (1-29%) were both variable. The LBVI and LVI are powerful prognostic factors in primary operable breast cancer. However, BVI was rarely specifically examined and its role in predicting survival is not clear. Further work is required using reliable specific staining to establish the routine use of LVI and BVI in the prediction of outcome in patients with primary operable breast cancer.