A gene 'thumbprint' was found in a group of 82 early stage breast tumors removed from patients. More than half of the patients whose primary tumors showed the genetic thumbprint went on to develop lung metastases, compared with only 10 percent of those whose primary tumors did not carry the gene set.

The findings shed new light on the biology of breast-cancer metastasis, and could lead to a possible prognostic tool and new targets for treatment, say the researchers at Memorial Sloan-Kettering Cancer Center (MSKCC) who identified the genes.

"Our work shows that the ability of a tumor to form metastases depends on the combined action of multiple genes -- and a different set of genes is required for each organ the tumor spreads to," said Joan Massagu