Dr Christos Sotiriou, head of the the microarray facility at the Jules Bordet Institute, Free University of Brussels, Belgium, told the conference that his multinational group had collaborated with Dr Adrian Harris (Oxford) and the National Cancer Institute (USA), to study samples from 99 patients whose clinical outcome was known. Using a microchip containing fragments of 7600 genes (a microarray) they analysed patients’ RNAs to identify which genes were related to known tumour and/or patient characteristics (such as whether the oestrogen receptor were positive or negative, tumour size and grade, lymph node involvement and menopausal status).
They found patterns of gene activity that were strongly associated with whether the oestrogen receptors were positive or negative, and moderately associated with tumour grade. It was more difficult to find genes associated with menopausal status, nodal status and tumour size.
By analysing how the entire group of genes in the study behaved, the researchers were also able to define new subgroups of patients. This may help them to characterise more successfully the nature and behaviour of the tumours.
Importantly, these subgroups were associated with sets of genes possibly predictive of the chances of a woman surviving breast cancer and surviving without a relapse.
Dr Sotiriou said: “The genes we found appear to work in a number of ways, through a variety of molecular ‘pathways’. We are still investigating these pathways and we are carrying out further investigations on a number of candidate genes associated with better clinical outcome.
“Our results need to be confirmed by looking at a different and bigger set of breast cancer tumours, so it will be several years before we might see the fruits of this research applied to patients in the clinic.”
For further information, contact Emma Mason, Margaret Willson, or Maria Maneiro at the EBCC3 press office in Barcelona, tel: +34 93 364 4487, or Emma Mason's mobile +44 (0)7711 296 986, or Margaret Willson's mobile + 44 (0)7973 853 347.