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MONTREAL, Aug. 9 2001: A team of Quebec researchers, led by Dr. François Rousseau of the Human and Molecular Genetic Research Department (HMGRD), Hôpital Saint-François d'Assise Research Centre, Centre hospitalier universitaire de Québec (CHUQ), has made a major breakthrough in the field of breast cancer by identifying a gene that protects against this disease.
This discovery is reported in the August 2001 issue of the prestigious scientific journal Cancer Research, a reference publication for this field. The gene identified by Dr. Rousseau's team is AR, an androgen receptor coding gene. Along with other genes, AR is part of the genetic baggage of all human beings, both men and women. However, this gene can present in different forms, called variants. The researchers have succeeded in identifying certain variants of this gene which provide women with greater protection against breast cancer. Approximately 15% of women present with a form of AR that is associated with a 50% decrease in their risk of developing breast cancer. Conversely, 85% of women present with the other form of AR that makes them twice as susceptible to developing breast cancer than women with the protective variant. "These results are of great interest as they indicate that a gene involved in the action of androgen, a hormone of well-known importance in men, plays a significant role in women's risk of developing breast cancer. Given that 85% of women carry the non-protective variant of the AR gene, this discovery could benefit a large number of women," explains Dr. François Rousseau, Associate Professor at Université Laval's Faculty of Medicine and Director of this research at the Hôpital Saint-François d'Assise Research Centre. "This breakthrough is all the more significant as it enables a better understanding of sporadic breast cancers, i.e. non-hereditary." Sporadic breast cancers represent 90% of all cases of breast cancer.
Source: Canadian News Wire
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Montreal - December 21, 1995: An international team of researchers including Dr. Steven Narod, of Women's College Hospital at the University of Toronto and Dr. Patricia Tonin of the Division of Medical Genetics of the Department of Medicine at McGill University, have discovered a second gene for hereditary breast cancer, BRCA2. Both investigators were part of the team which discovered the breast cancer susceptibility BRCA1 gene in September 1994.
Dr. Narod is holder of the Canadian Breast Cancer Foundation (Ontario Chapter) Chair in Breast Cancer Research and a member of the Canadian Genetic Diseases Network. Dr. Tonin is an Assistant Professor of Medicine at McGill and a Cancer Research Society/Medical Research Council of Canada Scholar.
The BRCA2 discovery was led by British scientists who worked collaboratively with researchers in Canada, Iceland, Holland, France, and the United States. In the findings of the research team, to be published in the December 21 edition of the British journal Nature, BRCA2 mutations were found in six families with multiple cases of breast cancer. Four of these families were followed by Dr. Narod and Dr. Tonin at McGill University.
"As with BRCA1", said Dr. Narod, "we expect that women who inherit the BRCA2 gene may have up to an 85% chance of developing breast cancer. Members of families with the BRCA2 gene also seem to be at greater risk for several other cancers, including ovarian cancer, prostate cancer, male breast cancer, and throat cancer."
While the BRCA1 gene took four years to clone, the BRCA2 gene took only one year. "Recent advances in molecular biology and the willingness of diverse groups to collaborate have really made a difference", said Dr. Tonin.
BRCA1 and BRCA2 genes together account for over 80% of families in Canada which are considered 'high risk' for breast cancer, i.e. where four or more cases have been recorded. Recent estimates of deaths resulting from breast and ovarian cancer in Canada are 1,700 in 1994. Genetic factors are responsible for up to 5% of breast cancer patients and 10% of ovarian cancer patients.
Said Dr. Michael Hayden, Scientific Director of the Canadian Genetic Diseases Network which partly funded Dr. Narod's research, "We are delighted that seed funding through the federal Networks of Centres of Excellence program, via the Medical Research Council of Canada, has contributed to both the BRCA1 and BRCA2 discoveries." He added, "The Network's facilities and collaborations across Canada will play an important part in the rapid progress of Dr. Narod's on-going research and eventual development of new diagnostics and therapies for these cancers."
The Canadian Genetic Diseases Network is a consortium of 38 of Canada's leading geneticists who are linked with twelve universities and hospitals across Canada, 10 core technology facilities, and 8 industrial partners to form an "institute without walls". The Network carries a mandate under the federal government's Networks of Centres of Excellence Program to perform leading-edge research and to create new commercial opportunities.
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CANADIAN SCIENTIST IS MEMBER OF TEAM DISCOVERING GENE FOR BREAST & OVARIAN CANCER
Montreal - October 7, 1994: Network scientist, Dr. Steven Narod, based at McGill's Montreal General Hospital heads a team of Canadian researchers who have contributed to isolating the gene that causes inherited forms of breast and ovarian cancer.
Working with other Network scientists, together with colleagues in Canada and the U.S., Dr. Narod directed the Canadian project for the cloning of the gene responsible for the cancer (BRCA1). The work has been continuing at a hectic pace for the last four years.
The findings of the Canadian and U.S. research teams were published in the October 7 edition of the journal SCIENCE.
Carriers of the gene that have the mutation are at increased risk of developing early onset breast and ovarian cancer. This latest breakthough is an important step towards the goal of the Canadian team to develop treatments or prevent the devastating disease.
Recent estimates of deaths resulting from breast and ovarian cancer in Canada are 1,700 in 1994. Genetic factors are responsible for up to 5% of breast cancer patients and 10% of ovarian cancer patients.
Network Scientific Director, Dr. Michael Hayden, commented "The Network's facilities and collaborations across Canada will be crucial to the rapid progress of Dr. Narod's on-going research and the eventual development of new diagnostics and therapies for these cancers."
Added Dr. David Shindler, Network Managing Director, "An additional outcome of these developments will be the clinical applications which will benefit Canadian women."
The Canadian Genetic Diseases Network is a consortium of 37 of Canada's leading geneticists who are linked with nine universities across Canada and 10 core technology facilities to form an "institute without walls". The network carries a mandate under the federal government's Networks of Centres of Excellence Program to perform leading-edge research and to work with industry partners on detection and treatment of genetically-transmitted disease.