By detecting cancer at an early stage, or even predicting who has an increased risk of being affected, the possibilities to treat the disease can be radically improved. In an international study led from Uppsala University the researchers have discovered that apparently healthy breast cells contain genetic aberrations that can be associated with an increased risk for non-familial breast cancer. The results have been published in the journal Genome Research.

In the Western world, approximately one out of ten women will develop breast cancer at some point in life. In most cases the disease is sporadic, i.e. it is not hereditary and is caused by mutations that have accumulated during the woman's lifetime.

Early detection is essential to successful treatment of tumours. Sporadic breast cancer is usually detected by the woman herself as a lump in the breast, or at a mammography examination. In contrast to familial breast cancer, where a few genes can be analysed and related to disease development, there is presently no reliable method to predict which women are at higher risk for developing sporadic breast cancer later in life.

New findings from an international research group, led by Professor Jan Dumanski at Uppsala University, show that genetic alterations in apparently healthy breast cells can be associated with an increased risk for sporadic breast cancer.

'We examined tissue samples that were located far away from the tumour and had been taken at the same time as a breast tumour had been removed. The tissues did not contain any tumour cells and looked like completely normal breast tissue. But when we analysed the DNA in these tissues we found that they contained genetic aberrations in well-known cancer genes, even though they appeared normal in the microscope', says Jan Dumanski, Department of Immunology, Genetics and Pathology.

The study shows that the development of sporadic breast cancer is a progressive process over many years, eventually producing a tumour. The genetic aberrations in the healthy cells make up a genetic "signature" that indicates an increases risk for developing non-familial breast cancer. This knowledge can be used for future improvements in diagnostics.

'The mutated genes create an altered protein pattern on the cells' surface, which could be used to detect those particular cells. This opens up possibilities to develop diagnostic methods that could identify women who are at risk for developing breast cancer, before the tumour is formed and much earlier than it can be detected by e.g. mammography', says Jan Dumanski.