Researchers believe they have made a significant discovery in the battle against breast cancer. Several teams working in collaboration around the world have identified changes in four genes that significantly raise the risk of breast cancer.
The researchers, led by Cancer Research UK's Cambridge Research Institute, said the discoveries are the most important genes associated with breast cancer since BRCA1 and BRCA2 were identified two years ago.
One of the newly identified genes, called FGFR2, appears to significantly raise the risk of breast cancer, making it the first truly common breast cancer susceptibility gene, according to the research published in the journals Nature and Nature Genetics.
Women who have two copies of the high-risk version of FGFR2, which stands for fibroblast growth factor receptor 2, have a 60 per cent greater chance of developing breast cancer than do those with no copies of the gene. Close to 60 per cent of the women they studied carried at least one copy.
Douglas Easton of the University of Cambridge led a team of researchers as they compared the genomes of some 4,400 women with breast cancer with those of about 4,300 who did not have the disease. They identified 30 differences in single DNA bases that seemed to be linked to the disease. These were then compared in more than 20,000 women with breast cancer and in a similar number of controls.
They found mutations in four genes that were more common in the people with breast cancer -- FGFR2, TNRC9, MAP3K1 and LSP1. Three of the newly discovered genes are involved in controlling the growth of cells.
Scientists already know that women with faulty copies of BRCA1 or BRCA2 have a 50 per cent to 85 per cent chance of getting breast cancer in their lifetimes. But they are rare genes, and account for only five per cent to possibly 10 per cent of breast cancer cases.
Researchers have been testing women for other genes associated with breast cancer, to find its causes, to understand how and why it develops, and to make more effective treatments.
For now, these latest findings will not lead to any changes in screening for breast cancer, since scanning these newly discovered genes would tell little about a woman's cancer risk. But as more and more genetic risk factors are uncovered, genetic profiling could one day give doctors a fine-grained picture of individual risk.
"As more genes are identified, tests will become more predictive," says Easton. "I wouldn't be at all surprised if there were dozens or hundred of genes involved."
Breast cancer is the most common cancer in Canadian women. It can also be found in men though this is very rare. One in nine Canadian women is expected to develop breast cancer during her lifetime. One in 27 will die of it.
Increasing age is the most important known risk factor. The risk of breast cancer increases throughout a woman's life.
Breast cancer death rates have declined in Canada in every age group since the mid-1990s because of better diagnosis and treatment techniques.
Source : www.ctv.ca
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