Preventive removal of the ovaries and Fallopian tubes can be life-saving for a small group of women who have inherited mutations in two genes related to breast cancer, a new international study suggests.

The BRCA1 and BRCA2 genetic mutations are associated with five to 10 per cent of cases of breast cancer, generally aggressive with a poor prognosis. Women who carry the BRCA 1 or BRCA 2 mutations have good screening options, doctors say. (Yannis Behrakis/Reuters)

Dr. Susan Domchek of the University of Pennsylvania school of medicine and her colleagues surveyed 2,482 women in North America and Europe with the mutations who had preventive cancer surgery — removal of both healthy breasts, both ovaries and both of the Fallopian tubes, which carry eggs from the ovaries to the uterus — before any tumours developed.

Removing ovaries and Fallopian tubes, a procedure known as salpingo-oophorectomy, was associated with better survival, the researchers reported in the Journal of the American Medical Association.

"Compared with women who did not undergo risk-reducing salpingo-oophorectomy, undergoing salpingo-oophorectomy was associated with lower all-cause mortality (10 per cent versus three per cent), breast cancer-specific mortality (six per cent versus two per cent), and ovarian cancer-specific mortality (three per cent versus 0.4 per cent)," the researchers wrote.

The findings clearly show that the reduction in risk translates into women living longer, Domchek said.

The BRCA mutations were determined between 1974 and 2008. Women in the study were followed until the end of 2009.

The study also found preventive mastectomy lowered the risk of breast cancer. No breast cancers were seen in the remaining tissue among women who had their breasts removed. However, since the study was observational in nature, it does not prove one choice is better, as other factors could have influenced cancer rates.

Difficult choice

Asking women to think about removing both healthy breasts and both healthy ovaries is a difficult decision, said Kelly Metcalfe, an associate professor of nursing who works on breast cancer prevention in BRCA1 and BRCA2 mutation carriers at Women's College Research Institute in Toronto.

"To be able to tell them that we now know — or this one study has shown, anyways — that we can increase your chances of survival, I think that this will be great information for women trying to make these difficult decisions," Metcalfe said.

There are good breast cancer screening options for women who carry the mutations, such as MRI. But for ovarian cancer, clinicians strongly suggest ovarian removal after a women no longer plans to have more children, since screening for ovarian cancer is poor and the lifetime risk of ovarian cancer among mutation carriers is so high, said Metcalfe.

Preventive mastectomy differs from the surgery in people who have breast cancer, Metcalfe noted. In the preventive surgery, the lymph nodes aren't removed, reconstructive surgery is often done at the same time, and women generally do well afterwards without body image issues.

Joanna Rudnick, a 36-year-old Los Angeles filmmaker, has known for nine years that she carries a mutation. Rudnick said she was glad to hear ovary removal may reduce her risk of breast and ovarian cancer

"This is one of the rare silver linings that has been learned from these prospective studies," said Rudnick, who plans to have her breasts and ovaries removed when she's 40.

About one to two per cent of Ashkenazi Jewish women are thought to carry one of the mutations, as do an estimated one in 300 Caucasians.

The test for the mutations costs about $3,000. All provinces and the U.S. have guidelines about who should be screened, based on ethnicity and family history of breast and ovarian cancer.

With files from The Associated Press