Researchers at the University of Gothenburg, Sweden, have for the first time identified 12 genes that could be associated with aggressive breast tumors. The discovery could result in more reliable prognoses and better treatment strategies for patients.
The results, published in the journal Clinical Cancer Research, are based on analyses of breast tumors from 97 female breast cancer patients. Half of these patients died within eight years of diagnosis, while the remainder survived for more than eight years.
Breast tumors consist of a heterogeneous mix of tumor cells which are markedly different in terms of their genes (DNA) and biological properties. The researchers used microarray techniques to study the overall picture of the tumors by measuring the amount of DNA and gene products (RNA) in each tumor. This enabled them to investigate the relationship between genetic changes and clinical parameters such as tumor properties and response to treatment.
"We've managed to identify 12 genes whose expression is associated with an aggressive form of breast cancer," says Toshima Parris, a PhD student at the Department of Oncology. "These 12 genes were much more prominent in patients who died within eight years than in those who survived."
Three of these 12 gene products were represented in much higher levels in aggressive breast tumors than in less aggressive tumors, whereas the nine remaining genes were found in lower levels in aggressive tumors.
These findings suggest that the activity of these genes could have an effect on tumor progression by impacting cell growth, motility and development. According to Parris, it may one day be possible to test for these markers in blood samples containing circulating tumor cells and/or tumor tissue from breast cancer patients in order to ascertain whether the patient may benefit from a particular treatment or drug to counteract this change in the genes' activity.
"We hope that diagnostics focusing on these genes at an early stage will result in more reliable prognoses, which could lead to more effective treatment regimens for patients with aggressive tumors," says Parris.
Clinical Cancer Research, August 1, 2010
University of Gothenburg (http://www.gu.se)