Angelina Jolie's decision to have her ovaries and fallopian tubes removed given her family history of cancer greatly reduces her risk of developing ovarian cancer, say experts who welcome the awareness she's raised.

Jolie revealed Tuesday she had a laparoscopic bilateral salpingo-oophorectomy last week after a marker on a blood test signalled what could be a sign of early cancer. She previously had a preventative mastectomy after her French-Canadian mother, Marcheline Bertrand, died of ovarian cancer. Her maternal grandmother also had the disease and an aunt died of  breast cancer.

'The medical community thanks Angelina Jolie for doing what she has done.' - Dr. Marcus Bernardini, surgical oncologist

BRCA mutations account for about five per cent of all breast cancers and four to 11 per cent of all ovarian cancers, according to the Canadian Cancer Society.

The average woman has a 12 per cent risk of developing breast cancer sometime during her life. Jolie carries the BRCA1 mutation, which bumps the lifetime risk for breast cancer about five times higher.

In the general population, the lifetime risk for ovarian cancer is one per cent. For women with the BRCA 1 or BRCA 2 mutation, the lifetime risk of ovarian cancer can be as high as 60 per cent.

Unlike breast cancer, ovarian cancer is often diagnosed at a late stage when the chance of surviving is low.

Ovary removal has benefits

"It's definitely a recommendation that we give women with a BRCA 1 or 2 mutation that they should strongly consider having their ovaries removed between the ages of 35 and 40 or after they've completed child bearing. It's the option available to women that's going to reduce their risk of developing ovarian cancer as most as we possibly can," said Kelly Metcalfe, a nursing professor at the University of Toronto and an adjunct scientist at Women's College Hospital.

"It's a huge benefit to these women to have their ovaries out."

Jolie's 2013 decision to have a preventive double mastectomy increased demand for genetic testing, known as the "Angelina effect."

Canadian research suggested the Angelina effect increased awareness and referral among women truly at high risk for hereditary breast cancer who may have put testing on the back burner until then.

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Angelina Jolie's decision to publicize her surgeries to prevent cancer has helped raise awareness of BRCA 1 and 2 mutation testing and options. (Michael Sohn/Associated Press)

In Canada, BRCA testing is available to women who meet certain risk criteria, including family history of breast cancer and ethnicity.

Some gynecological specialists applauded Jolie's decision to go public.

"The medical community thanks Angelina Jolie for doing what she has done because it does increase awareness. Ovarian cancer is a terrible disease," said Dr. Marcus Bernardini, a surgical oncologist at Toronto's Princess Margaret Cancer Centre.

"The most important message that needs to get out there is there is no effective screening for the type of ovarian cancer that she was at risk for."

Symptoms associated with ovarian cancer tend to be vague, such as bloating or urinary changes. Ovarian Cancer Canada advises women to see a doctor if symptoms are frequent, persistent or new. The most common and most serious form of ovarian cancer is now thought to originate in the fallopian tubes.

Other options include birth control pills and frequent checks, such as with the CA-125 blood test Jolie had yearly because of her family history. Unfortunately, Metcalfe said, the CA-125 marker doesn't always provide useful information and ovarian cancer can develop without any warning signs.

Transvaginal ultrasounds are also offered to women at high risk, Metcalfe said, but they may also fail to pick up early ovarian cancer.

Procedure likely to have side-effects

Jolie wrote about how she prepared herself to enter menopause and mapped out her estrogen and progesterone replacement options.

The decision to pursue a preventive salpingo-oophorectomy comes with side-effect risks. In the short-term, these include hot flashes and sexual dysfunction. Longer term, Metcalfe said, preliminary evidence suggests there can be effects on the bones, heart function and cognitive function.

Women who have the surgery are monitored and the longer-term effects are being studied to try to develop better interventions.

The Canadian Cancer Society estimates 2,700 women are diagnosed with ovarian cancer every year and 1,750 women  die from it annually. 

With files from CBC's Amina Zafar and Melanie Glanz