Breast cancer risks for one of potentially the most important genes associated with breast cancer after the BRCA1/2 genes have been reported in the New England Journal of Medicine (August 7th 2014).
A collaborative group of 17 centres in eight countries analysed data from 154 families without BRCA1 or BRCA2 mutations which included 362 family members with PALB2 gene mutations. The study was led by two researchers from the University of Cambridge, Dr Marc Tischkowitz, (Department of Medical Genetics) and Dr Antonis Antoniou (Department of Public Health and Primary Care).
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 where 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.
Dr Marc Tischkowitz says: “Since the BRCA1 and BRCA2 mutations were discovered in the mid-90s, no other genes of similar importance have been found and the consensus in the scientific community if more exist we would have found them by now. PALB2 is a potential candidate to be ‘BRCA3’. As mutations in this gene are uncommon, obtaining accurate risk figures is only possible through large international collaborations like this.
“Now that we have better risk figures for this gene, we are in a position to provide genetic counselling and advice. If a woman is found to carry this mutation, we would recommend additional surveillance, such as MRI breast screening.”
The Study was funded by the European Research Council, Cancer Research UK and multiple other international sources: