Inherited Factors Play an Important Role in Breast Cancer Progression According to new Study

New research in mice and five independent collections of human breast tumors has enabled National Cancer Institute (NCI) scientists to confirm that genes for factors contributing to susceptibility for breast cancer metastasis can be inherited. The new findings support earlier results from the same laboratory and appear in the Jan. 1, 2009, issue of "Cancer Research."

The study results also show that gene activities in tumor cells and immune cells that infiltrate, or invade, tumors can contribute to the development of expression profiles, called gene signatures, that are predictive of cancer progression.

The analysis of normal mouse tissue as well as tumors transplanted into mice suggests that predictive, or prognostic, gene signatures that point to a tumor's potential for spreading throughout the body can be the result of both inherited and non-inherited factors, with inherited factors being more consistently predictive. The research team that reported these findings is from the Center for Cancer Research at NCI, which is part of the National Institutes of Health.

The researchers were able to perform their analyses by using advances in microarray technology, which allows scientists to scan vast amounts of genetic information and identify gene signatures that can be used to predict cancer outcomes. Many scientists had assumed that metastatic ability is primarily determined by somatic, or non-inherited, gene mutations in tumor tissue.

"Our earlier studies clearly established that inherited factors also play an important role in metastatic progression and can help distinguish which tumors have a propensity to metastasize," said author Kent W. Hunter, Ph.D., head of NCI's Metastasis Susceptibility Section in the Laboratory of Cancer Biology and Genetics. "Hopefully in the future we will be able to determine which women are more likely to have a tumor that would metastasize, and we could then tailor therapy specifically for them, avoiding the use of harsh treatments for those with a low probability of metastasis."

"Our study provides additional evidence of the role of inherited genes in human breast cancer progression. Therefore our next step is to improve our current understanding of the role of the epithelium and stroma in tumor progression and develop more effective therapeutic strategies based on our new knowledge," said Hunter.