Though many of the risk factors are out of a woman's control, there are ways to reduce women's risk of getting the disease. Researchers theorize that each ovulation creates an opportunity for a cancer-causing mutation to occur, thus mechanisms to reduce these opportunities in effect reduce risk. At this time, it is impossible to completely eliminate a woman's risk for ovarian cancer, but experts have established that the following can reduce risk of ovarian cancer:

• Oral contraceptives: Regular use of oral contraceptives reduces risk of ovarian cancer by 40 to 50 percent when taken for at least 5 years. Researchers attribute the reduction in risk to a protective effect of raised progestin levels, breaks in the ovulation cycle, or a combination of both. Additionally, several clinical studies have reported that the effects last for years after pill use has ceased.

A comparable reduction for "high risk" women is not as definitive. Recent studies surrounding the risk reduction value of oral contraceptive use in women who carry the BRCA1 or BRCA2 gene mutation have published conflicting results. While a 1998 study reports that oral contraceptives reduce risk for women with BRCA1 or BRCA2 genetic mutations, a study published in July 2001 found that oral contraceptives do little to reduce risk in these women. Further research is required to determine the effect of oral contraceptives on women with BRCA1or BRCA2 mutations.

• Pregnancy & breast-feeding: Pregnancy and prolonged breast-feeding have been found to significantly reduce the risk of ovarian cancer. Although it is unclear at this time whether the protective effect of pregnancy relates to hormonal factors or to the suppression of ovulation, studies show a 40 percent reduction in risk for women who bear at least one child. There is an additional 10 to 15 percent risk reduction with each successive term pregnancy, though reduction does not appear to extend beyond the fourth pregnancy.
  
  
• Tubal ligation: A recent study found tubal ligation to be particularly effective in women who carry the BRCA1 gene mutation. The method by which the procedure protects women is not yet known. Some studies suggest that tubal ligation moderately disrupts blood flow to the ovary, in turn, diminishing the number of menstrual cycles. Other studies propose that the procedure blocks the passage of cancer-causing materials from the vagina to the ovaries.
  
  
• Hysterectomy: Hysterectomy has also been found to reduce risk of developing ovarian cancer. The reason for its protective effect is thought to be similar to that of tubal ligation.
  
  
• Removal of the ovaries [prophylactic oophorectomy]: It has been shown that prophylactic oophorectomy reduces incidence of ovarian cancer. This procedure is usually suggested only for women at very high risk - those with two or more first-degree relatives with ovarian cancer [or ovarian and breast cancer] or those who have been genetically determined to carry a BRCA1 or BRCA2 gene mutation - and past their childbearing years. However, even after oophorectomy, women [including those with BRCA1 and 2 gene mutations] still have an approximate 1.8 percent risk of developing cancer in the peritoneum, a close relative of ovarian cancer.

Clearly these methods are not appropriate for all women. Each individual must assess the risks and benefits of these factors with the assistance of her health care professional to determine if she should take action.

Increase Risk	Decrease Risk
Age	Oral Contraceptive Use
Family History	Pregnancy And Breastfeeding
Not Bearing Children	Tubal Ligation
Personal History Of Cancer	Hysterectomy/Removal Of Ovaries

Note: Statistics may vary slightly from article to article based on the source and timing of the data.