(adapted from an article by Lisa Priest, Globe & Mail, May 24, 2008)

Because one in 44 Ashkenazi Jewish persons carries a mutation putting a woman at increased risk of breast cancer, Women's College Research Institute in Toronto is conducting a research study offering free testing to Ontario residents. Screening for three inherited breast cancer gene mutations has been available since late May to one thousand Jewish women with no known history of breast or ovarian cancer, as well as to those women who have such a history but who have never been tested.

Ashkenazi Jews, of Central and Eastern European ancestry, constitute nearly 90% of Jews in Canada – and half live in the Toronto area. It is estimated that only one person in 400 in the non-Ashkenazi-Jewish population carries similar mutations (BRCA1 and BRCA2).

The test has many implications: If a woman tests positive, she must have inherited the mutation from a parent. Her children have a 50% chance of carrying the gene, as do her siblings. It is estimated that about 70% of BRCA1 and BRCA2 carriers develop breast cancer by age 70. In addition, about 40% of BRCA1 carriers develop ovarian cancer by age 70, and about 15-20% of BRCA2 carriers.

Women who test positive will be referred to specialized screening – MRIs, pelvic exams, vaginal ultrasounds and blood tests. They may also receive prescriptions for tamoxifen or oral contraceptives. Some women who test positive may opt for a bilateral mastectomy or oophorectomy (removal of the ovaries).

If this study proves worthwhile, it could alter the way testing is offered across Canada by recognizing a woman's inherent risk of cancer, due to her ancestry.