Removing Ovaries Reduces Breast Cancer Risk in Some Women

Women with BRCA1 mutations should have their ovaries removed by the age of 35, researchers said Monday.

Women with BRCA1 and BRCA2 mutations are at an increased risk of breast cancer. The latest study by the University of Toronto in Canada and colleagues found that women can lower their risk of breast cancer if they undergo preventive ovarian surgery (prophylactic oophorectomy) by age 35. The overall risk of death by the age of 70 was reduced by 77 percent in women (with BRCA mutations) who had their ovaries removed.

Although, earlier studies have shown that oophorectomy can prevent breast and ovary cancer, this is the first study to show that the procedure is also linked with greater chances of living till 70 years of age.

"To me, waiting to have oophorectomy until after 35 is too much of a chance to take," said Steven Narod, MD, professor of medicine at the University of Toronto in Canada and the study's lead author. "These data are so striking that we believe prophylactic oophorectomy by age 35 should become a universal standard for women with BRCA1 mutations."

BRCA1 and BRCA2 are human genes that code for tumor suppressor proteins. When either of the two genes carries a mutation, the protein is not produced. Cells of people with this mutation might have DNA damage that can lead to cancer, according to National Cancer Institute.

About 12 percent of women in the general population will develop breast cancer during their lifetime when compared to 55 to 65 percent of women with BRCA1 mutation and 45 percent of women with BRCA2 mutation. The risk of ovarian cancer is also higher in women with BRCA 1 or 2 mutations, NCI says.

Preventive ovarian surgery isn't an easy procedure and comes with several side-effects. The procedure essentially throws a woman into menopausal stage, CNN reports.

The procedure is recommended for women with a high risk of developing breast cancer. Removing the ovaries reduces the level of estrogen in the body. Estrogen is known to help breast cancers grow.

Data for the current study came from 5,787 enrolled in the Hereditary Ovarian Cancer Clinical Study (1995-2005). All the women had mutations of BRCA1 and BRCA2 genes.

Around 2123 women had already undergone a surgery to remove their ovaries before the study and 1,390 underwent oophorectomy during the study follow-up period. And, 2,274 did not have oophorectomy, according to a news release.

Researchers found that oophorectomy reduced the risk of ovarian cancer by 80 percent. According to the team, delaying the procedure increased chances of breast cancer.

They also showed that prophylactic oophorectomy lowered the risk of early death by 77 percent.

These results could make a real difference for women with BRCA mutations, who face tough decisions about whether and when to undergo a prophylactic oophorectomy. For women with BRCA1 mutations, these results suggest that surgery should be performed as soon as it is practical," said Don Dizon, MD, ASCO Cancer Communications Committee member, according to a news release.

Actress Angelina Jolie announced last year that she has a mutation of BRCA1 gene. She underwent preventive double mastectomy to reduce her chances of developing breast cancer, CNN reported.

The study is published in the Journal of Clinical Oncology.