Gene increases risk of breast cancer to 1 in 3 by age seventy

Aug. 11, 2014

Research published last week in the New England Journal of Medicine provides evidence that another gene besides the BRCA 1 / 2 genes is associated with increased risk of breast cancer. Women with mutations in the PALB2 gene have on average a one-in-three chance of developing breast cancer by the age of seventy.

In a study run through the international PALB2 Interest Group a team of researchers from 17 centers in eight countries, led by the University of Cambridge, analyzed data from 154 families without BRCA1 or BRCA2 mutations. The study included 362 family members with PALB2 gene mutations. Women who carried rare mutations in PALB2 were found to have on average a 35% chance of developing breast cancer by the age of seventy. However, the risks were highly dependent on family history of breast cancer; carriers with more relatives affected by breast cancer were at higher risk. Only a very small proportion of women worldwide carry such mutations, and the researchers point out that additional studies are required to obtain precise estimates of mutation carrier frequency in the population.

PALB2 is known to interact with both the BRCA1 and BRCA2 and was first linked with breast cancer in 2007. As is the case for women who carry mutations in BRCA1 or BRCA2, women with PALB2 mutations who were born more recently tended to be at a higher risk of developing breast cancer than those born earlier. The reason why is unclear, but the researchers speculate that it may be related to factors such as later age at first childbirth, smaller families, and better surveillance leading to earlier age of diagnosis. Read the article preview.

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