Ovarian cancer

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

Causes, incidence, and risk factors

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

The cause is unknown.

Risk of developing ovarian cancer may be due to:

• The fewer children a woman has and the later in life she gives birth, the higher her risk of ovarian cancer.
• Certain gene problems (defects in the BRCA1 or BRCA2 genes) are responsible for a small number of ovarian cancer cases.
• Women who have had breast cancer or have a family history of breast or ovarian cancer have an increased risk of ovarian cancer.
• Women who take estrogen replacement only (not with progesterone) for 5 years or more may have a high risk of ovarian cancer. Birth control pills, however, decrease the risk of ovarian cancer.
• Fertility drugs probably do not increase the risk of ovarian cancer.
• Older women are at highest risk of 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.

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 possiblewith ovarian cancer. But 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
  
  
• Back pain for unknown reasons that worsens over time
• Vaginal bleeding that occurs 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 (increased urinary frequency or urgency )

Signs and tests

A physical exam is often normal. With have advanced ovarian cancer, the doctor may find a swollen abdomen often due to collection (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 is often done to find the cause of symptoms. A biopsy will be done 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 early stages surgery 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 done by a specialist in female organ cancers has been shown to result in a higher success rate.

Chemotherapy is used after surgery to treat any cancer that remains. Chemotherapy can also be used if the cancer comes back. Chemotherapy is most often given into the veins. Sometimes it is given directly into the abdominal cavity (intraperitoneal).

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

After surgery and chemotherapy, patients should be followed up closely:

• A physical exam (including pelvic exam) every 2 - 4 months for the first 2 years. This is followed by every 6 months for 3 years, and then each year. 
• A CA-125 blood test at each visit if the level started out high.
• The doctor may also order periodic computed tomography (CT) scans of your chest, abdomen, and pelvic area.

Support Groups

You can ease the stress of illness by joining a cancer support group. Sharing with others who have common experiences and problems can help you not feel alone.

Expectations (prognosis)

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

• About 3 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
• Fluid in the abdomen (ascites)
• Blockage of the intestines

Calling your health care provider

Contact your health care provider if you are a woman over 40 years old who has not recently had a pelvic exam. Routine pelvic exams 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. Pelvic ultrasound or blood tests, such as the CA-125 has not been found to be effective and is not recommended.

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

Removing the ovaries and tubes in women who have a problem in the BRCA1 or BRCA2 gene may reduce the risk of developing ovarian cancer. But ovarian cancer may still develop in other areas of the pelvis.

References

1. Armstrong D. Ovaries and fallopian tubes. In: Abeloff MD, Armitage JO, Niederhuber JE, et al. eds. Abeloff’s Clinical Oncology. 4th ed. Philadelphia, PA: Elsevier Churchill-Livingstone; 2008:chap 93.  
2. 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.
3. Coleman RL, Ramirez PT, Gershenson DM. Neoplastic diseases of the ovary: screening, benign and malignant epithelial and germ cell neoplasms, sex-cord stromal tumors. In: Lentz GM, Lobo RA, Gershenson DM, Katz VL, eds.Comprehensive Gynecology. 6th ed. Philadelphia, PA: Elsevier Mosby; 2012:chap 33.
4. National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines): Ovarian cancer: including fallopian tube cancer and primary peritoneal cancer. Version 1.2013. Available at: http://www.nccn.org/professionals/physician_gls/pdf/ovarian.pdf. Accessed November 16, 2012.