Cancer is a group of many related diseases. All cancers begin in cells
, the body's basic unit of life. Cells make up tissues, and 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 and die, 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
Tumors can be benign or malignant.
Benign tumors are not cancer.
Usually, doctors can remove them. Cells from benign tumors do not spread to other parts of the body. In most cases, benign tumors do not come back after they are removed. Most important, benign tumors are rarely a threat to life.
Malignant tumors are cancer.
They are generally more serious. Cancer cells can invade and damage nearby tissues and organs. Also, cancer cells can break away from a malignant tumor and enter the bloodstream or the lymphatic system. That is how cancer cells spread from the original (primary
) tumor to form new tumors in other organs. The spread of cancer is called metastasis
Endometrial cancer, or cancer that forms in the tissue lining the uterus, is one of the most common cancers in American women. It is sometimes called uterine cancer
, but there are other cells in the uterus that can become cancerous, including muscle or myometrial cells. These become sarcomas, which are less common. Most endometrial cancers are adenocarcinomas
, or cancers that start in cells that make mucus and other fluids.
Women who use estrogen without progesterone, especially for long periods of time, are at an increased risk for endometrial cancer. Women taking the drug tamoxifen to prevent or treat breast cancer also have an increased risk. Obese women have higher levels of estrogen in their bodies, which also puts them at higher risk for this disease. Women who have had an inherited form of colorectal cancer have a higher risk of developing uterine cancer than other women.