Booklet: What You Need to Know about Ovarian Cancer

The Ovaries

The ovaries are a pair of female reproductive organs. They are located in the pelvis, one on each side of the uterus. Each ovary is about the size and shape of an almond. The ovaries have two functions: they produce eggs and female hormones.

Each month, during the menstrual cycle, an egg is released from one ovary. The egg travels from the ovary through a fallopian tube to the uterus.

The ovaries are the main source of female hormones (estrogen and progesterone). These hormones control the development of female body characteristics, such as the breasts, body shape, and body hair. They also regulate the menstrual cycle and pregnancy.

What Is Cancer?

Cancer is a group of more than 100 different diseases. They all affect the body's basic unit, the cell. Cancer occurs when cells become abnormal and keep dividing and forming more cells without control or order.

Like all other organs of the body, the ovaries are made up of many types of cells. Normally, cells divide to produce more cells only when the body needs them. This orderly process helps keep us healthy.

If cells keep dividing when new cells are not needed, a mass of tissue forms. This mass of extra tissue, called a growth, or tumor, can be benign or malignant.

• Benign tumors are not cancer. They can usually be removed and, in most cases, they do not come back. Most important, cells from benign tumors do not invade nearby tissues and do not spread to other parts of the body. Benign tumors are rarely life threatening.

  In women under age 30, most ovarian growths are benign, fluid-filled sacs called cysts. Cysts may occur during a women's monthly cycle and often go away without any treatment. If a cyst does not go away, the doctor may suggest removing it, especially if it is causing problems or seems to be changing. In some cases, the doctor may decide to wait and watch for changes with ultrasonography or other tests.

• Malignant tumors are cancer. Cancer cells can invade and damage tissues and organs near the tumor. Also, cancer cells can break away from a malignant tumor in the ovary and spread to other organs in the abdomen and form new tumors. Ovarian cancer spreads most often to the colon, the stomach, and the diaphragm. The cancer cells also can enter the lymphatic system or the bloodstream and spread to other parts of the body. The spread of cancer is called metastasis.

There are several types of ovarian cancer. Most ovarian cancers are epithelial carcinomas, which begin in the lining of the ovary. (Other types of ovarian cancer are rare and are not discussed in this booklet.)

When cancer spreads, the new tumor has the same kind of abnormal cells and the same name as the original (primary) tumor. For example, ovarian cancer that spreads to the colon is metastatic ovarian cancer. It is not colon cancer, even though the new tumor is in the colon.