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For the first time in Canada, Jewish women will be offered the chance to alter their genetic destiny by taking a test – at no cost to them – that will determine whether they are at high risk of developing breast and ovarian cancers.

By screening for three inherited breast cancer gene mutations common to those of Ashkenazi Jewish ancestry, Women's College Research Institute scientists have an ambitious goal: to prevent the dreaded disease before it strikes.

They plan to do that by offering adult Jewish women in Ontario, with no known family history of breast or ovarian cancer, the blood test to screen for three specific mutations of the BRCA1 and BRCA2 genes, beginning this Thursday. Jewish women with a family history of breast or ovarian cancer who have never been tested are also eligible.

If expanding genetic testing to this group proves worthwhile, it could alter the way the testing is offered across Canada by recognizing one's inherent risk of cancer, simply due to ancestry.

The goal of the test is “to prevent cancer,” said Steven Narod, director of the familial breast cancer research unit at Women's College Research Institute in Toronto. One in 44 Ashkenazi Jewish people carry the mutation, he noted; in the general population, an estimated one in 400 individuals carries a mutation in BRCA1 or BRCA2.

For Ashkenazi women, a group with mainly Central and Eastern European ancestry, the test could reveal a risk they never knew they had. Sarah Neumin, a 44-year-old psychotherapist in Toronto, said there was no breast cancer in her family – until her sister was diagnosed with it three years ago. Ms. Neumin has since tested positive for a mutation of the BRCA1 gene that she inherited from her father.

“We had no cancer at all in the family,” said Ms. Neumin, who now undergoes regular screening for breast and ovarian cancer. “We didn't have a lot of females in our extended family who didn't die in the Holocaust. You can't really do a family tree because a lot of people really didn't live that long.”

Canada's Jewish population is overwhelmingly Ashkenazi: 327,360 out of a total of 370,055, according to figures from Charles Shahar, chief researcher of the national census project for UIA Federations Canada. And about half of the Ashkenazi Jewish population – 165,175 – live in Toronto.

Based on the one-in-44 risk factor, 7,440 Ashkenazi Jewish Canadians are unwitting carriers of BRCA1 or BRCA2 genetic mutations.

Until now, Jewish ancestry was not enough to warrant testing for hereditary breast and ovarian cancer anywhere in Canada; nor is there any known organized population screening of Jewish women in the United States. Several years ago, Dr. Narod, who is also a University of Toronto professor, did a trial for recurring mutations among Polish women similar to the one on Jewish women starting next week.

Rabbi Jennifer Gorman, who is also director of youth activities for the United Synagogue of Conservative Judaism, Eastern Canada region, said she can see the test one day being offered the way screening for Tay-Sachs, a fatal genetic lipid storage disorder, is to couples of Jewish ancestry.

“The rate of this gene is so high,” she said. “It will be one of the tests that is normally done.”

A genetic crystal ball

The test is for three genetic mutations that recur in the Jewish population, due to the so-called founder effect, which occurs when a new colony is started by a few members of the original population, often due to geographic or religious isolation.

According to researchers, 40 per cent of today's Ashkenazi Jewish population arose from a group of four founding mothers, who lived somewhere in Europe within the past 2,000 years.

With the marvels of science, their female descendants are being offered the opportunity to peek into the genetic version of a crystal ball. The test has implications for a woman's family: If she tests positive, she must have inherited the genetic mutation from a parent. Her children run a 50-per-cent chance of carrying the gene, as do her siblings. Testing may have implications for those seeking life or critical care insurance, although policies already in place are typically not affected.

Not seeking an answer, however, also carries a steep cost.

About 70 per cent of women who are BRCA1 mutation carriers will develop breast cancer by age 70; about 40 per cent will develop ovarian cancer by the same age. Those who carry the BRCA2 genetic mutation face the same breast cancer risk as those BRCA1 mutation carriers, but their risk of developing ovarian cancer is lower than the BRCA1 group – between 15 and 20 per cent by age 70, according to Dr. Narod's group.

“It empowers women, as far as I'm concerned, to make choices for themselves,” said Rebecca Dent, a medical oncologist at Sunnybrook Health Sciences Centre in Toronto, who works closely with Dr. Narod.

Women who test positive can be referred to specialized screening. Some of that screening includes magnetic resonance imaging scans of the breasts, pelvic exams, transvaginal ultrasounds and the CA-125 blood test, which measures a protein found in greater concentration in ovarian cancer cells than in other cells, according to the Jewish Population Screening Study paper done by Dr. Narod's research unit.

As well, there are ways to prevent cancer, including drug therapies such as tamoxifen and oral contraceptives. There are also surgical options such as removal of the breasts and ovaries.

By being hooked into a system where the women are followed more closely, there is more opportunity to participate in new drug or screening techniques as they become available, Dr. Dent said.

Dr. Narod, who holds the Canada Research Chair in breast cancer, said the testing is also a good investment: Focusing on those three recurring mutations in the Jewish community means the test is relatively easy to do as the entire genome does not require sequencing.

With the blood test costing about $25 a patient, to be paid for through his research grant, he expects to find a mutation for BRCA1 and BRCA2 in about one in 50 Jewish women. If that turns out to be the case, he estimates it will cost only $1,250 to find someone at high risk of developing breast and ovarian cancer. (Those figures do not include added costs of genetic counselling, laboratory technician time and doctor consultation times.) And finding one patient actually means finding many more – as it leads to the identification and testing of other family members.

Eligible Ontario patients must be willing to travel to Toronto for the test, which is being offered to 1,000 women as part of a research study, at which point it will be re-evaluated.

“If we see 1,000 women with no family history of breast cancer and find no mutation, that tells us the criteria will stay the same,” said Kelly Metcalfe, clinician scientist at Women's College Research Institute. “If we are finding mutations, that suggests the criteria should change, that we should be offering general [Jewish women] population screening to any Ashkenazi Jewish woman who is interested in the test.”

‘No-brainer' testing

Melissa Lieberman-Moses was 32 and in her last trimester of a twin-girl pregnancy in late 2003 when she found a pea-sized lump in her left breast. She had no family history of breast or ovarian cancer, and while doctors thought the lump was probably nothing to worry about, they sent her for an ultrasound, then a biopsy.

It revealed an early-stage breast cancer. She later tested positive for a BRCA1 mutation. As it turned out, that family history hadn't yet revealed itself because her father was the carrier of the genetic mutation.

She underwent a double mastectomy – as well as an oophorectomy, which is removal of the ovaries.

Having the genetic testing, Dr. Lieberman-Moses feels, has saved the lives of some of her family members, who now know what they may face in the future. But she does worry about her children, twins, Aviva and Talia, and son, Sammy, all of whom could be carriers.

“It was worth doing every single measure I could, the most aggressive things I could,” said the 37-year-old Toronto psychologist. “I wanted to live to see my kids get older.” She thinks it's a “good idea for every Jewish woman to get tested so she can take steps to prevent this horrible disease.”

Aletta Poll, genetic counsellor for the familial breast cancer research unit of the Women's College Research Institute, cautioned this test is appropriate only for the Jewish population.

“We're just looking at three specific mutations of these two genes,” Ms. Poll said. “If you are not Jewish and you take this test, it doesn't really mean much. If you are Jewish, you can still have another mutation in these two genes but it's not that likely.”

In a telephone interview, Reform Rabbi Michal Shekel, executive director of the Toronto Board of Rabbis, described the genetic testing as a “no-brainer,” adding that Jewish law – Halacha – insists one is obligated to take care of oneself.

Likewise, Conservative Rabbi Gorman said she can see the testing being talked about among couples the way other genetic diseases are discussed.

“If we know we can reduce our risk and we know we can save lives, then we have to look into the future and say where are we going to go with this,” she said. “… The more education we put out there, the more likely we can conquer this disease. And now, this is one more piece of it.”