The researchers said that the genes are more than markers that identify the presence of metastatic cancer. These genes are mediators that enable fragments of breast cancer tumors to take root in the lungs.
The scientists are hopeful that their research will give clinicians a new set of molecular tools to test tumor biopsies for the activity of these specific genes. This, in turn, should help guide treatment by permitting the early diagnosis of breast cancers that will ultimately metastasize to the lung.
The genes that have been identified produce proteins that may move to the top of the "most wanted list" of prime targets for therapies to thwart metastasis, said the study's senior author Joan Massagu, a Howard Hughes Medical Institute investigator at Memorial Sloan-Kettering Cancer Center. Massagu and his colleagues are optimistic that their technique can be extended to other types of metastatic cancer, where it should aid in identifying genetic characteristics of metastatic tumors to aid diagnosis and treatment.
Massagu, postdoctoral fellow Andy J. Minn, and graduate student Gaorav P. Gupta, led the research team that published its findings in the July 28, 2005, issue of the journal Nature.
Until now, researchers had taken a largely ad hoc approach to identifying genes that might influence how breast cancer spreads. Such studies usually involved overactivating individual candidate genes and observing whether that change in activity affected the cancer's ability to spread. Such piecemeal studies did not yield a comprehensive, unbiased picture of the broad genetic changes that drive metastasis, according to Massagu.