New Breast Cancer Genes

Breast cancer starts as a tumor in the breast and as the tumors grow, they begin to shed cancerous cells that metastasize or travel to other parts of the body, such as the lymph nodes, bones of the pelvis, spine, legs, ribs, and skull, liver, lungs, and brain. (Breast Cancer Metastasis in Women, University of Michigan Comprehensive Cancer Center)

Researchers at Memorial Sloan-Kettering Cancer Center in New York have identified a panel of genes out of 22,000 (can’t seem to find the names of the genes in either the news releases or the abstract of the original research paper) that appears to predict breast cancer’s severity and its ability to spread specifically to the lungs. (Dr. Koop, July 27, 2005)

Last month, the EN2 gene was found to be active in cell lines derived from human breast tumours. (Oncogene, June 20, 2005) Mouse mammary cells genetically engineered to carry the EN2 gene also caused tumors. Unlike BRCA1 or BRCA2 which increase the risk of breast cancer mostly in people with a family history, the EN2 gene may be involved in the more common sporadic form found in people with no known affected relatives.

Identifying the types of genes involved in breast and other cancers (aka oncogenes) not only helps us understand how and why cancers develop, it could eventually lead to predictive tests and targeted treatments.

“Metastasis, particularly to visceral organs such as the lung, accounts for the majority of breast cancer related mortality,” said Andy J. Minn, MD, PhD, a radiation oncologist at MSKCC, and first author of the Nature paper. The new research “may provide genetic markers to aid oncologists in clinical management, offer potential therapeutic targets to develop drugs against metastasis, and give basic researchers a paradigm to understand how metastatic ability is acquired,” Dr. Minn said.