Causes, incidence, and risk factors

Ovarian cancer is the fifth most common cancer among women, and it causes more deaths than any other type of female reproductive cancer.

The cause is unknown.

The risk for developing ovarian cancer appears to be affected by several factors. The more children a woman has and the earlier in life she gives birth, the lower her risk for ovarian cancer. Certain genes defects (BRCA1 and BRCA2) are responsible for a small number of ovarian cancer cases. Women with a personal history of breast cancer or a family history of breast or ovarian cancer have an increased risk for ovarian cancer.

Women who take estrogen replacement only (not with progesterone) for 5 years or more seem to have a higher risk of ovarian cancer. Birth control pills, however, decrease the risk of ovarian cancer.

Studies suggest that fertility drugs do not increase the risk for ovarian cancer.

Older women are at highest risk for developing ovarian cancer. Most deaths from ovarian cancer occur in women age 55 and older.

Symptoms

Ovarian cancer symptoms are often vague. Women and their doctors often blame the symptoms on other, more common conditions. By the time the cancer is diagnosed, the tumor has often spread beyond the ovaries.

You should see your doctor if you have the following symptoms on a daily basis for more than a few weeks:

• Bloating or swollen belly area

• Difficulty eating or feeling full quickly

• Pelvic or lower abdominal pain; the area may feel "heavy" to you (pelvic heaviness)

Other symptoms are also seen with ovarian cancer. However, these symptoms are also common in women who do not have cancer:

• Abnormal menstrual cycles

• Digestive symptoms:

  • Constipation

  • Increased gas

  • Indigestion

  • Lack of appetite

  • Nausea and vomiting

• Unexplained back pain that worsens over time

• Vaginal bleeding that occurs in between periods

• Weight gain or loss

Other symptoms that can occur with this disease:

• Excessive hair growth that is coarse and dark

• Sudden urge to urinate

• Needing to urinate more often than usual (See: Increased urinary frequency or urgency )

Signs and tests

A physical examination is often normal. However, if you have advanced ovarian cancer, it may reveal a swollen belly area and fluid in the area (called ascites).

A pelvic examination may reveal an ovarian or abdominal mass.

A CA-125 blood test is not considered a good screening test for ovarian cancer. However, it may be done if a woman:

• Has symptoms of ovarian cancer

• Has already been diagnosed with ovarian cancer to determine how well treatment is working

Other tests that may be done include:

• Complete blood count and blood chemistry

• Pregnancy test (serum HCG)

• CT or MRI of the pelvis or abdomen

• Ultrasound of the pelvis

Surgery such as a pelvic laparoscopy or exploratory laparotomy may be done to evaluate symptoms and perform a biopsy to help make the diagnosis.

No lab or imaging test has ever been shown to be able to screen for or diagnose ovarian cancer in its early stages.

Treatment

Surgery is used to treat all stages of ovarian cancer. For earlier stage ovarian cancer, it may be the only treatment. Surgery involves:

• Removal of the uterus (total hysterectomy)

• Removal of both ovaries and fallopian tubes (bilateral salpingo-oophorectomy)

• Partial or complete removal of the omentum, the fatty layer that covers and pads organs in the abdomen

• Examination, biopsy, or removal of the lymph nodes and other tissues in the pelvis and abdomen

Surgery performed by a specialist in female reproductive cancer has been shown to result in a higher success rate.

Chemotherapy is used after surgery to treat any remaining disease. Chemotherapy can also be used if the cancer comes back. Chemotherapy may be given into the veins, or sometimes directly into the abdominal cavity (intraperitoneal).

Radiation therapy is rarely used in ovarian cancer in the United States.

After surgery and chemotherapy, patients should have:

• A physical exam (including pelvic exam) every 2 - 4 months for the first 2 years, followed by every 6 months for 3 years, and then annually

• A CA-125 blood test at each visit if the level was initially high

• Your doctor may also order a computed tomography (CT) scan of your chest, abdomen, and pelvic area and a chest x-ray.

Support Groups

For additional information and resources, see cancer support group.

Expectations (prognosis)

Ovarian cancer is rarely diagnosed in its early stages. It is usually quite advanced by the time diagnosis is made

• About 3 out of 4 women with ovarian cancer survive 1 year after diagnosis.

• Nearly half of women live longer than 5 years after diagnosis.

• If diagnosis is made early in the disease and treatment is received before the cancer spreads outside the ovary, the 5-year survival rate is very high

Complications

• Spread of the cancer to other organs

• Loss of organ function

• Fluid in the abdomen (ascites)

• Blockage of the intestines

Calling your health care provider

Call for an appointment with your health care provider if you are a woman over 40 years old who has not recently had a pelvic examination. Routine pelvic examinations are recommended for all women over 20 years old.

Call for an appointment with your provider if you have symptoms of ovarian cancer.

Prevention

There are no standard recommendations for screening for ovarian cancer. Screening women with pelvic ultrasound or blood tests, such as the Ca-125 has not been found to be effective and is not recommended.

BRCA testing may be done in women at high risk for ovarian cancer.

Removal of the ovaries and tubes in women who have a mutation in the BRCA1 and BRCA2 genes may reduce the risk of developing ovarian cancer, although ovarian cancer may still develop in other areas of the pelvis.

References

1. Mørch LS, Løkkegaard E, Andreasen AH, Krüger-Kjaer S, Lidegaard O. Hormone therapy and ovarian cancer. JAMA. 2009;302:298-305.
2. National Comprehensive Cancer Network. National Comprehensive Cancer Network Clinical Practice Guidelines in Oncology: Ovarian Cancer. 2009;v.2.
3. Jensen A, Sharif H, Frederiksen K, Kjaer SK. Use of fertility drugs and risk of ovarian cancer: Danish population based cohort study. BMJ. 2009;338:b249.
4. Berek JS, Chalas E, Edelson M, Moore DH, Burke WM, Cliby WA, et al. Prophylactic and risk-reducing bilateral salpingo-oophorectomy: recommendations based on risk of ovarian cancer. Obstet Gynecol. 2010 Sep;116(3):733-43.

Review Date: 12/15/2011.

Reviewed by: Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.