Boston Children’s Hospital Studying ‘Triple-Negative’ Breast Cancers

Researchers are studying how to treat the 'most aggressive' form of breast cancer.

Triple-negative breast cancer is a subtype of breast cancer occurring in less than 15 percent of cases. It is also the most aggressive and most difficult breast cancer to treat, says Dr. Judy Lieberman, chair in cellular and molecular medicine at Boston Children’s Hospital and professor of pediatrics at Harvard Medical School. “Triple-negative” refers to the lack of gene expression of two receptors for female hormones (estrogen and progesterone) and one for a growth factor (Her2). “This type of breast cancer afflicts young women and minority women disproportionately,” she says. “In particular, it is the breast cancer type that runs in families. The inherited BRCA gene mutations greatly increase the risk of getting this type of cancer. So young women whose mothers or aunts had breast cancer before menopause are very much at risk.”

Lieberman and her team at Boston Children’s studied “triple-negative” breast cancers and found that it may be vulnerable to drugs that attack the proteasome. By selectively turning genes off throughout the genomes of triple-negative tumor cells in vitro, Lieberman’s team found that these cells absolutely require active proteasomes in order to live. When turned off, the cells die. The work is in a new paper published in the journal, Cancer Cell. What this all means is that Lieberman and her team found a personalized medicine approach to treat triple-negative breast cancer.

“This data suggests that triple-negative breast cancers may respond to treatment with drugs similar to a proteasome inhibitor that revolutionized the care of patients with the blood cancer multiple myeloma,” Lieberman says. “The good news is that there are already FDA approved proteasome inhibitor drugs [and about a dozen more related proteasome inhibitor drugs are in clinical development], so testing this new approach in at risk cancer patients should be possible without years of delay. Also it should be possible to identify the patients most likely to respond based on the molecular features of their cancer.”