Our bodies continually replace dead cells with new ones. With millions of new cells being made everyday, mistakes can and do happen, causing abnormal cells. Normally cells have ways of checking and identifying problems. Defective or abnormal cells are destroyed. If something goes wrong with this detection system, the abnormal cells are permitted to grow.
Cells grow by first increasing in size and then splitting into two.
Normally, new cells are created at the same rate as old cells die. Cancer cells do not maintain this normal balance. They divide at a faster rate than cells die, causing the cancer to grow. Normal cells do not travel to other parts of the body or the body's immune system detects and destroys them before they can grow. Most women are shocked to find out that they have had their breast cancer for years before it was discovered.