A new study led by a UK scientist has discovered a gene variant that could reduce risk of breast cancer.
The study is published in the journal Nature Genetics.
Led by Dr Angela Cox of Sheffield University’s Medical School, the large international team of researchers found that a particular variant of a gene known as CASP8 is likely to reduce a woman’s risk of developing breast cancer by nearly 10 per cent.
The researchers were working under the auspices of the Breast Cancer Association Consortium (BCAC) which was established to carry out case controlled studies on very large cohorts so that small sensitivities can be picked up using statistical methods.
The researchers examined data from 14 different studies covering 33,000 women who were mostly of European descent.
Evidence already exists of gene variations increasing risk of breast cancer. This is the first study however that suggests a gene variation reducing the risk of breast cancer.
The scientists genotyped nine different single-nucleotide polymorphisms (SNPs) or DNA sequence variations which previous research had already discovered had possible links with breast cancer. The one that showed significant reduction in risk was CASP8 D302H.
The researchers suspect that CASP8 plays a role in triggering cell suicide (apoptosis) in cancerous or damaged cells.
The body is full of cells that become damaged or develop abnormally and have their cell death programme activated genetically. Cancer is thought to occur when these suicide programmes are interrupted or just don’t happen for some reason.
This study’s main conclusion is that with sufficient numbers of cases it is possible to calculate the small contribution that genes make to breast cancer risk.
Other research has found links between gene variations and breast cancer risk, for example the genes BRCA1 and BRCA2.
BRCA1 and BRCA2 are tumour suppressors that stops cells from growing too fast and the proteins that they code repair damaged DNA. Over 600 mutations of BRCA1 and 450 of BRCA2 have been found, many of which are linked to increased breast cancer risk.
Another recent international study conducted by scientists from the Dana Faber Cancer Institute and Harvard Medical School identified another gene, PALB2. They found this contributed to 1 per cent of increased risk in breast cancer in a Finnish population. PABL2 is thought to work with BRCA2 in switching genes on and off.
“A common coding variant in CASP8 is associated with breast cancer risk.”
Angela Cox, Alison M Dunning, Montserrat Garcia-Closas et al.
Nature Genetics Published online: 11 February 2007, doi:10.1038/ng1981
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Written by: Catharine Paddock
Writer: Medical News Today