Breast cancer is a cancer that starts in the cells of the breast. Worldwide, breast cancer is the second most common type of cancer after lung cancer (10.4% of all cancer incidence, both sexes counted) and the fifth most common cause of cancer death. Breast cancer is a cancer that starts in the cells of the breast.
Cancer begins in cells, the building blocks that make up tissues. Tissues make up the organs of the body.Normally, cells grow and divide to form new cells as the body needs them. When cells grow old, they die, and new cells take their place. Sometimes, this orderly process goes wrong. New cells form when the body does not need them, and old cells do not die when they should. These extra cells can form a mass of tissue called a growth or tumor.
• Benign tumors are not cancer: Benign tumors are rarely life-threatening and generally, benign tumors do not grow back when they are removed. Cells from benign tumors do not invade the tissues around them, and do not spread to other parts of the body.
•Malignant tumors are cancer: Malignant tumors are generally more serious than benign tumors. They may be life-threatening. Malignant tumors often can be removed, but sometimes they grow back. Cells from malignant tumors spread by breaking away from the original (primary) tumor and entering the bloodstream or lymphatic system. The cells invade other organs and form new tumors that damage these organs.
When breast cancer cells spread, the cancer cells are often found in lymph nodes near the breast. Also, breast cancer can spread to almost any other part of the body. The most common are the bones, liver, lungs, and brain. The new tumor has the same kind of abnormal cells and the same name as the primary tumor. For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer. For that reason, it is treated as breast cancer, not bone cancer....