About Tumor Angiogenesis
When a malignant tumor is contained within one area and has not spread to the surrounding tissue, like the one in the picture above, the medical term is “carcinoma in situ.” If this tumor does not keep growing, that means it is just lying there quietly (“dormant cancer cells“). It is not likely to cause harm unless it starts growing.
To keep growing, these tumors start to create their own blood vessels to supply them with the extra oxygen, glucose and hormones they need to survive and keep getting bigger. That process of developing a blood supply system is called angiogenesis (the growth of new blood vessels). Once a tumor does this, it can start to invade the surrounding tissue. This is called an invasive cancer, and you can see what that looks like here.
Active cancer cells can enter the bloodstream or lymphatic system and move to other parts of the body to start the process of forming a tumor all over again somewhere else (metastatic or secondary cancer)…Read more about how cancer cells grow and spread Institute for Quality and Efficiency in Health Care