What Is Ovarian Cancer?

When cancer forms in the ovaries it is called ovarian cancer. The ovaries are reproductive glands in women where eggs form. One ovary is located on each side of the uterus. The hormones estrogen and progesterone are also made in the ovaries.1

Cancer is a condition in which cells undergo biological changes and begin to grow and multiply in an uncontrolled way. Cancer can form in nearly any organ in the body and spread to other parts of the body.

What is ovarian cancer?

Cancer that begins in the ovaries is called ovarian cancer. The ovaries are a pair of female reproductive glands where the ova (eggs) are formed. Research shows that many ovarian cancers may start in the far end of the fallopian tubes. The ovaries are mainly made up of 3 different kinds of cells. Each type of cell can become a different kind of tumor:1

  • Epithelial tumors begin from the cells on the outer layer of the ovary. This is the most common type of ovarian tumor.
  • Germ cell tumors begin in the cells that produce the eggs.
  • Stromal tumors start from cells that are part of the tissue that holds the ovary together. These tumors also make the hormones estrogen and progesterone.

Ovarian cancer, like other types of cancer, can spread (metastasize) to other parts and organs of the body.

Figure 1. Female reproductive system

Female reproductive organs include the fallopian tubes, ovaries, uterus, cervix, endocervix, exocervix, and vagina.

What is advanced ovarian cancer?

Advanced ovarian cancer is generally defined as cancer that has spread outside the ovary. This means the cancer has spread to other places within the pelvis or abdomen. It may also spread further away to other areas or organs of the body.2

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Ovarian cancer may already be advanced when it is first diagnosed. In other cases, it may be diagnosed as advanced ovarian cancer following treatment.2

Like other cancers, ovarian cancer is classified into stages. In most cases, advanced ovarian cancer includes stages II through IV. Staging is based on several factors, including:3

  • Size of the tumor
  • Whether it has spread to nearby lymph nodes
  • Whether it has spread to other areas or organs

The stage is usually based on lab results from tissue samples taken during surgery and the features the doctor sees during surgery. If surgery is not done right away, the cancer will be given a clinical stage. This is based on a physical exam, biopsy, and other tests like imaging tests done before surgery.3

What are the risk factors for ovarian cancer?

Anyone with ovaries can develop ovarian cancer. However, there are some factors that can increase your risk of developing the disease. Risk factors for ovarian cancer include:4

  • Inherited gene mutations – The breast cancer genes BRCA1 and BRCA2 increase the risk of both breast cancer and ovarian cancer. There are also other gene mutations that can increase ovarian cancer risk.
  • Family history of ovarian cancer – Those with 2 or more close relatives with the disease have an increased risk.
  • Estrogen hormone replacement therapy, especially large doses or long-term use.
  • Earlier menstruation and/or later menopause.

It is important to remember that risk factors do not always mean you will develop the disease.

What are the signs and symptoms of ovarian cancer?

Early-stage ovarian cancer rarely causes any symptoms. As ovarian cancer becomes more advanced, symptoms may start appearing. These symptoms can be nonspecific and general. This means they can go unrecognized as ovarian cancer or mistaken for other conditions.4,5

Signs and symptoms of ovarian cancer can include:4,5

  • Abdominal bloating or swelling
  • Feeling full when eating, especially after eating a small amount
  • Weight loss
  • Pelvic discomfort
  • Changes in bowel habits
  • Frequent need to urinate
  • Upset stomach
  • Back pain
  • Pain during sex
  • Changes in menstruation, such as irregular bleeding or heavier periods
  • Feeling very tired

These symptoms do not necessarily mean you have ovarian cancer. However, if you are experiencing symptoms that are different from how you normally feel, are persistent, or get worse, talk with your doctor. It can be helpful to keep a symptom log so you can show your doctor the pattern or how often you have symptoms.

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Written by: Jaime Herndon | Last reviewed: May 2021