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Ovarian Cancer: Overview and Risk Factors

Ovarian cancer is the second most common gynecologic cancer (after cervical cancer) and the leading cause of death from gynecologic cancer in the United States. It generally affects women aged 40 to 65.

The ovary is composed of epithelial cells (along the surface), germ (egg–producing) cells, and sex cord stroma (connective tissue surrounding the ovary). These cell types, each of which has the potential for malignant transformation, constitute the main types of primary ovarian cancer. In addition, metastatic breast and gastrointestinal cancers commonly affect the ovaries. The most common ovarian malignancy is epithelial carcinoma (approximately 90% of cases), which is the focus of this chapter.

In the early stages, ovarian cancer usually exhibits subtle and nonspecific symptoms that rarely prompt a woman to seek medical attention. More severe symptoms caused by ovarian torsion or rupture are rare. As a result, only about 20% of cases are diagnosed at an early stage.

Nonspecific symptoms may include:

  • Anorexia and fatigue.
  • Low abdominal discomfort (eg, pressure, swelling, cramps, bloating, flatus).
  • Low back pain.
  • Early satiety and maldigestion.
  • Nausea, diarrhea, and constipation.
  • Frequent urination.
  • Weight gain or loss.
  • Irregular or abnormal vaginal bleeding, and dyspareunia.
  • Unilateral or bilateral lower extremity edema.

Risk Factors

Possible risk factors are listed below, although the exact mechanism of induction or protection in ovarian cancer is not clearly understood.

Nulliparity or infertility.

Age. Most ovarian cancers occur in women over 50 years, with the highest risk for those over 60.

Family history. Women who have relatives with ovarian cancer have an approximately 3–fold increased risk, with multiple affected relatives raising the risk further.

BRCA gene mutation. Women with a BRCA1 or BRCA2 mutation have a 25% to 45% lifetime risk of ovarian malignancy, with BRCA1 generally presenting a higher risk.

Race. White women have higher rates of ovarian cancer than black women.1

Previous cancer. Women with a history of breast or colon cancer may have an increased risk.


Diet. See Nutritional Considerations.

In addition, estrogen–replacement therapy, smoking, and obesity may be risk factors. Breast–feeding, previous pregnancy (and especially multiparity), oral contraceptive use, tubal ligation, and hysterectomy may reduce risk for ovarian cancer.


Ovarian Cancer: Diagnosis and Treatment >>