Newly Identified Gene Mutation Could Help Explain How Breast Cancer Spreads

A newly identified genetic mutation could shed more light on how breast cancer spreads and possibly guide treatment for women with the disease, according to a study from Magee-Womens Research Institute and the University of Pittsburgh Cancer Institute.

The research represents the most comprehensive analysis to date of the genomic changes that occur in breast cancer progression. The findings were presented last month at the 2014 San Antonio Breast Cancer Symposium.

Researchers from Magee-Womens Research Institute and the Pitt Cancer Institute sequenced frozen breast tumor samples from six patients, beginning with the primary tumor when the cancer was first diagnosed through the cancer’s progression to metastatic disease. Using multiple sequencing techniques, the team identified a new gene created by two separate genes that fused together as a result of unstable DNA. This fusion gene was identified in a metastatic tumor sample and is believed to play a part in the spread of the original breast cancer.

“We applied all of our sequencing technologies to the tumors in order to understand the changes that occur between the first breast cancer occurrence and late-stage disease,” said Ryan Hartmaier, a research instructor at the Magee Women’s Research Institute and the study’s lead author.

Because several types of breast cancer are fueled by the hormone estrogen, estrogen-blocking treatment is often recommended to prevent the disease from spreading. However, the fusion gene did not respond to estrogen-blocking treatment, contributing to the breast cancer’s spread.

“This research helps us further understand the genomic landscape of metastatic breast cancer,” said Adrian Lee, the study’s senior author and director of the Women’s Cancer Research Center, which is a collaboration between the University of Pittsburgh Cancer Center and the Magee-Womens Research Institute.

“The new class of genetic changes takes us another step further in personalized medicine—and could change the way we treat certain patients if we are able to identify who will develop this genetic mutation,” added Lee, who is also a professor of pharmacology and chemical biology in the Pitt School of Medicine.