Removing ovaries cuts risk of cancer death in women with BRCA gene

Watch the video above: Removing ovaries cuts risk of cancer death in women with BRCA gene. Minna Rhee reports. 

TORONTO — Opting for an ovary removal surgery can lower the risk of death by 77 per cent in women who carry a BRCA gene mutation, a new Canadian study says.

Actress Angelina Jolie shed light on the link between genetics and breast cancer after she had a double mastectomy last May. The Oscar-winning actress tested positive for the BRCA gene, which left her vulnerable to breast cancer. But the mutation also means women face a spike in risk of ovarian cancer, another aspect that’s often overlooked.

Research has already suggested that a preventive oophorectomy — or the removing of the ovaries — reduces the risk of ovarian and breast cancer in women with the BRCA1 or BRCA2 genes. But scientists haven’t looked into the best age for the surgery and its impact on mortality.

READ MORE: Breast cancer and genetics: Angelina Jolie’s double mastectomy

Lead researcher Dr. Steven Narod, of Women’s College Hospital in Toronto, says there’s three reasons why the surgery cuts death risk down so significantly.

“The first being it prevents ovarian cancer, the second thing we found is it prevents breast cancer – that has been established but not so clearly as it is now. But the third thing that was probably most surprising was women who had had breast cancer in the past benefitted just as much,” Narod told Global News.

Narod said the team expected to see the risk lowered by 40 to 50 per cent, “But certainly…77 per cent was more than we expected,” he said.

The team looked at 5,783 women with the BRCA gene who had a preventive oophorectomy in their study. The surgery was linked to:

–       an 80 per cent reduction in the risk of ovarian, fallopian and peritoneal cancer

–       a 77 per cent lower risk of death from all causes

–       a 66 per cent lower risk of death from all causes in women who already had breast cancer in the past

The risk is significantly cut if women with the BRCA gene undergo this surgery at age 35, Narod said.

READ MORE: Can a U.S. company own your genes? Patenting DNA is at the centre of US law controversy

Oophorectomies are safe procedures, but they carry complications. Premature menopause, a decline in cardiovascular health and bone health are some concerns, the doctors note.

Their next steps are to better understand these risks for women who undergo the surgery. But for now, they say their findings point to a “clear benefit” to this surgery, especially for younger women with the genetic mutation.

Narod’s findings were published Monday in the Journal of Clinical Oncology.

Narod’s colleagues at Women’s College Hospital recently published another study on the BRCA gene and a double mastectomy. That research suggested that for women with breast cancer and the BRCA mutation, a double mastectomy could cut the risk of dying from their sickness in half.

READ MORE: Double mastectomy could save the lives of women with BRCA gene: study

Most women tend to go for a lumpectomy and radiation or a single mastectomy. But for women with the BRCA gene, the cancer typically returned in their opposite breast. In that scenario, the risk of dying doubled.

What is the BRCA mutation?

There are two types of BRCA – or breast cancer susceptibility gene. They’re called BRCA1 and BRCA2. The pair are tumour-suppressing genes, according to the National Cancer Institute. They’re meant to stabilize the cell’s DNA and prevent uncontrollable cell growth. But if they mutate, the BRCA genes can lead to breast cancer or ovarian cancer.

One in 250 women have the BRCA1 or BRCA2 genes in Canada. The average woman has an 11 per cent risk of breast cancer.

But if a woman has one of these harmful genes, their risk increases by 80 per cent. They also face an elevated risk of ovarian cancer. The typical woman has a one per cent risk of ovarian cancer – with BRCA1, that risk jumps to 60 per cent. With BRCA2, the risk is 40 per cent.

carmen.chai@globalnews.ca

Follow @Carmen_Chai