The study, funded by Cancer Research UK, showed that before becoming cancerous, breast cells with the BRCA1 gene mutation undergo changes similar to those normally seen in late pregnancy.
Although this is early research, in the future doctors could screen women with BRCA1 mutations to monitor changes to their breast cells, which could help inform who might benefit from preventative surgery, and to give reassurance to those who can wait.
BRCA1 mutations significantly increase the risk of developing breast cancer at a younger age. Many women who discover they carry the faulty gene choose to have a preventative mastectomy. This involves surgically removing some or all of the healthy breast tissue, which can reduce but not eradicate the risk of developing breast cancer.
Not all women who have BRCA1 mutations will go on to develop cancer so for some, this life-changing surgery may be unnecessary, or could at least be delayed until early warning signs are spotted.
Researchers led by Karsten Bach and Dr Sara Pensa at the University of Cambridge wanted to develop a method to detect the early changes occurring in BRCA1-affected breast cells indicating that they are progressing towards breast cancer.
The team analysed the mammary tissue of 15 mice at various ages carrying the BRCA1 mutation to look for changes in the tissue that were happening before the mice developed tumours.
The researchers found that having a BRCA1 mutation triggered certain pathways to be switched on in a type of stem cell called a luminal progenitor breast cell that are only activated during pregnancy. These messages tell the progenitor cell to turn into alveolar cells, which make up the chambers in the breast where milk-production takes place during late pregnancy.
Image: Mammogram image
Credit: slgckgc on Flickr
Reproduced courtesy of the University of Cambridge