Too much tissue is made, and tumors are formed. Tumors can be benign or malignant . Benign tumors are not cancer. They do not spread to other parts of the body and are seldom a threat to life. Often, benign tumors can be taken out by surgery, and they are not likely to return.
Malignant tumors are cancer.
They can invade and destroy nearby healthy tissues and organs. Cancer cells can also break away from the tumor and enter the bloodstream or lymphatic system . Thatis how cancer can spread to other parts of the body. This spread is called metastasis . Even if cancer is removed from the breast, the disease sometimes returns because cancer cells already may have spread.