What Is Ovarian Cancer?

Ovarian cancer is cancer that starts in the ovaries, the female reproductive organs that produce eggs.

Ovarian cancer is the seventh most common cancer among women and causes more deaths than any other type of female reproductive cancer. It is the fifth highest cause of all cancer deaths in women.

The cause of ovarian cancer is not yet known.

What Are the Risk Factors for Ovarian Cancer?

All women are at risk of developing ovarian cancer. Most ovarian cancers are found in women older than 60 and are more often found in white than African-American women. Some factors that may increase the risk of ovarian cancer include:

  • Family or personal history. Women who have a mother, daughter or sister with ovarian cancer are at a higher risk; women with a family or personal history of breast, uterus, colon, or rectum cancer are also at increased risk of ovarian cancer.
  • Postmenopausal
  • Never been pregnant
  • Hormone replacement therapy

What Are the Symptoms of Ovarian Cancer?

The symptoms of ovarian cancer are vague and often go unnoticed until the disease has spread beyond the ovaries. More than 70 percent of patients are not diagnosed until ovarian cancer is at an advanced stage.

Women who have any of the following symptoms on a daily basis for more than two to three weeks should see their gynecologist immediately, particularly if they have not had these problems before:

  • Bloating
  • Pelvic or abdominal pain
  • Difficulty eating or feeling full quickly
  • Change in bowel habits
  • Urinary urgency or frequency
  • Sudden unusual weight loss or weight gain

How Is Ovarian Cancer Diagnosed?

Diagnosis starts with a thorough medical history and physical exam, including a pelvic exam.

Additional testing may include:

  • Imaging tests - such as ultrasound, computed tomography (CT) scan, x-ray, MRI or colonoscopy to identify tumors and determine if the cancer has spread to other areas
  • Blood tests - to measure, among other things, levels of CA-125, a protein in the blood that may be higher than normal in women with ovarian cancer
  • Biopsy - the removal of a tissue sample or fluid for examination under a microscope to see if cancer cells are present
  • Surgical procedures - such as a laparotomy or pelvic laparoscopy to view the ovaries and other pelvic organs, do a biopsy, or determine whether the cancer has spread

Types of Ovarian Cancer

When diagnosed early, ovarian cancer can be limited only to the ovaries, but at later stages, ovarian cancer will have metastasized or spread to other parts of the body. There are three main categories of ovarian cancer:

Epithelial. This is the most common type of ovarian cancer and includes about 90 percent of diagnosed cases. The tumor typically starts in the epithelial tissue or outside lining of the ovaries and is usually diagnosed in older patients. The risk of epithelial ovarian cancer increases with age with the average patient age around 63.

Germ cell. Germ cell tumors occur in only five percent of ovarian cancer cases and starts in the egg-producing cells of the ovaries. They can occur at any age but are more commonly found in patients under 30 years old.

Sex cord stromal. These tumors are also rare and occur in only five percent of ovarian cancers. They start from the ovarian stromal tissue (supporting cells of the ovary) and usually are associated with increased hormone levels, including estrogen, progesterone, and testosterone. Sex cord stromal tumors occur in young and older women.

Similar Cancers

Fallopian tube cancer and primary peritoneal cancer are two other gynecologic cancers which behave like ovarian cancer. Their symptoms and treatment are similar to ovarian cancer.

  • Fallopian tube cancer is a rare cancer that starts from the fallopian tubes or oviducts (tubes which allow the egg to pass from the ovaries to the uterus).
  • Primary peritoneal cancer is a cancer that starts in the tissue which lines the abdomen and pelvis. Although rare, women can still develop this cancer after their ovaries have been removed.

Can Ovarian Cancer Be Prevented?

Unfortunately, no screening tests for ovarian cancer are available or recommended at this time. However, patients who have a strong family history of breast or ovarian cancer or who may have a genetic predisposition to ovarian cancer should be seen by a gynecologic oncologist and followed closely. While it is not yet known how to prevent ovarian cancer, research suggests women may be able to reduce their risk through:

  • Birth control pills - taken for five years or more; however, oral contraceptives may increase the risk of developing breast cancer, so weigh the risks and benefits with your gynecologist.
  • Pregnancy and breast feeding
  • Genetic testing and surgical prevention - Women with a family or personal history of certain cancers may consider genetic testing to determine if they carry genetic mutations that place them at higher risk.*

*In high-risk cases, or when a hysterectomy is being performed for other medical reasons, removal of both ovaries and fallopian tubes may be considered.