Genes hold cancer risk

KELLEY KORBIN

Your grandmother may have passed down more than just her Sabbath candlesticks. Generations of Ashkenazi Jews, with little intermarriage, have created what British Columbia Cancer Agency genetic counsellor Jenna Scott describes as a "contained gene pool." That's both good news and bad news.

The bad news is that Ashkenazi women have a two to three per cent chance of carrying one of three genetic mutations for breast and ovarian cancers. In fact, about 40 per cent of ovarian cancers and 12 per cent of breast cancers in Jewish women are a result of one of these three mutations – and 80 per cent of carriers will develop cancer without preventative treatment.

The good news is that because of the work of leading Canadian researchers like Dr. Steven Narod, Canada research chair in breast cancer and professor of public health sciences at the University of Toronto and director of the family breast program at Women's College Hospital, the specific gene mutations have been isolated, making genetic testing for these mutations fairly routine.

Normally, only women with risk factors, specifically a relative who had breast or ovarian cancer, would qualify for the genetic testing. However, Narod suspects that these defects may exist in Jewish women who have no family history. Therefore, he is currently leading a study in Ontario to offer free genetic screening for any Ashkenazi Jewish women. Narod told the Independent he believes that many women with a hereditary predisposition to these cancers simply aren't being referred for testing, often because family doctors don't get an adequate history from their patients.

For women who do test positive, Narod and his team will offer psychological counselling and preventative treatments that include drugs like tamoxifen for breast cancer and birth control pills for ovarian cancer or the more invasive mastectomy or ovarectomy, removing the organs at risk. Historically, 60 per cent of women who test positive opt for ovarectomy, while one-quarter opt for mastectomy.

The study is only available to Jewish women in Ontario. Ashkenazi Jewish women who would like to be tested in British Columbia must qualify by having a family history of breast or ovarian cancer. Narod said, "B.C. is notorious for having the slowest genetic testing turnaround. I suppose if you phoned for an appointment today you might get one in a year, whereas at my hospital we tend to book them within three weeks. I can't comment on that specifically but my experience with B.C. is that, while they offer an elaborate genetic testing with a lot of pre- and post-test counselling, in order to provide that intensity of service, they restrict the coverage by having more narrow criteria for testing and they also restrict the coverage by having inordinately long testing waiting times."

Narod continued in his condemnation of the B.C. process, criticizing what he called "archaic practices" that include counselling women about a disease before testing when, in the majority of cases, the women will test negative. In his opinion, the counselling should come only after a positive result.

Scott said that waiting lists for these tests in British Columbia range from six to eight months, with results about two months later. She agreed that B.C. coverage is more limited than Ontario's, but said service here is comparable to most other provinces. The discrepancy with Ontario is mainly due to budget and staffing limitations, where British Columbia has half the genetic counsellors by population ratio than Ontario, she explained. Nevertheless, she said she is "proud of the quality of service" her department provides and takes issue with Narod's criticism of her department's protocol. She stated, "I feel the genetic counselling is a very important part of the genetic testing process ... the philosophy, which is consistent throughout North America and Europe is ... to ensure people make an informed choice and are aware of the implications of the results for both themselves and their families [before testing]."

Local community member Alisa Bowman is fighting ovarian cancer. She has two sisters who both have daughters of their own.

Bowman said, "The B.C. Cancer Agency has a whole process that goes with the testing. They will meet with me and whoever else I want to be there, i.e. siblings, parent. We will have a counselling session, talk about the implications. I want to get tested. What I have realized about ovarian cancer is that it really is the silent killer. There is so much education on breast cancer and how it can be detected early through self-examination or mammograms, but women don't realize what the signs are for ovarian cancer. If I can help my family by being tested, then hopefully they will become educated in the possible signs of ovarian cancer."

Scott urges any Jewish women with a family history of breast or ovarian cancer to visit www.bccancer.ca and speak to their family doctor about their risk factors.

Kelley Korbin is a Vancouver freelance writer living in Vancouver.

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