We will discuss the meaning for metastatic breast cancer in order to understand metastatic breast cancer vs. breast cancer. Metastasis is the process that results in cancer cells expanding. It's when cancer spreads (metastasized) out of the breast area to another component, such as breast cancer in the liver lung, the bone, or brain. It is caused when the breast cancer cells degrade the tumor in the breast and then travel through the body via the lymph system or bloodstream. Metastasis can also occur when cancer cells separate from the breast tumor in its original location and spread to other organs. The cancer cells also move via the lymphatic system, or bloodstream (the lymph nodes network as well as vessels that remove viruses, bacteria, and cell waste) Source url:- metastatic breast cancer vs. breast cancer