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Breast Cancer Genetics: Questions and Answers |
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Written by Theresa Maher
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Monday, 28 May 2007 |
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Ever since the discovery that mutations in BRCA1 and BRCA2 genes heighten the risk of breast cancer, scientists have evinced a keen interest in breast cancer genetics. Although these genes were discovered in 1994, there have been no other significant genes linked to the development of the leading cancer in women. Until now that is. Several teams of researchers have discovered a bunch of genes that may play a crucial role in increasing the risk of breast cancer in women.
Breast cancer is one of the most common cancers in women, particularly in the developed countries. Over a million women are diagnosed worldwide every year, according to the International Agency for Research on Cancer (IARC) in Lyon, France. The American Cancer Society says that 200,000 women are diagnosed with the condition each year and 40,000 succumb to it.
The National Cancer Institute estimates that at least 13.2 percent of the women born today will be diagnosed with breast cancer at some point in their lives. In such a situation scientists say that if genes or genetic markers for breast cancer are detected early enough, chances of survival might increase significantly. The newly discovered genes hold out hope for a simple test in future that can accurately predict the risk of breast cancer in women.
Below are some questions and answers regarding breast cancer genetics and the latest news regarding the newly discovered genes and genetic markers.
What is all the furor of new genes implicated in breast cancer risk?
Three studies have discovered a clutch of genes and genetic markers that predispose women for developing breast cancer in later life. The studies appear in the latest issue of the journal Nature and Nature Genetics.
How many genes are now thought to increase breast cancer risk?
A study by Cancer Research UK's Cambridge Research Institute has discovered four new genes as being responsible for increasing the risk of breast cancer. Reporting in the journal Nature, the researchers said they used a new technique that potentially speeds up gene identification.
This technique compares the DNA from a breast cancer sufferer with that of a healthy patient and theorizes that the differences are mostly likely linked to genes causing breast cancer. In the current study, researchers studied 50,000 women; half of whom had breast cancer and half of whom were healthy.
Researchers identified four genes called FGFR2, TNRC9, MAP3K1 and LSP1 as increasing risk of breast cancer.
What is the significance of the UK study?
Researchers say BRCA1 and BRCA2 are very rare among the general population. However the newly identified genes are found in one in six and one in 16 women thereby increasing the chances of early detection and thus prevention of future breast cancer.
The researchers also found five regions of DNA that were present more often in breast cancer patients indicating that these regions may have variations linked to the eventual development of the cancer.
What are the findings of the CGEMS project?
The Cancer Genetic Markers of Susceptibility or CGEMS is collaboration between National Cancer Institute and Harvard. According to the NCI the initiative "is a three-year study designed to identify common genetic variations associated with risk for prostate and breast cancer."
Researchers found that genetic variations of FGFR2 gene were linked to increased risk of breast cancer. European women and their descendants had a 20 percent increased risk of cancer if they carried one faulty copy of the FGFR2 gene. Two mutations in this gene increased the risk of breast cancer by 40 to 60 percent. This study appeared in nature Genetics.
What are the findings of the third study?
Reporting in Nature Genetics, researchers said genetic variants on chromosome 2 and on chromosome 16 may increase the risk of estrogen-receptor-positive breast cancer. One gene variant in this study was present close to TNRC9, which is also confirmed by the UK study.
What should consumers read into the above studies?
With the identification of more genes, researchers hope to be able to formulate a simple test that can detect genetic variants. If the test becomes possible, then consumers, particularly women can look forward to early detection of breast cancer risk and start treatment accordingly.
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Last Updated ( Monday, 28 May 2007 )
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