This Could Be a Game-Changer in Treating Triple-Negative Breast Cancer
By LIDA TUNESI
Triple-negative breast cancers are more likely to spread through the body and are more likely to recur than other breast cancers. And they disproportionately affect African American and Hispanic women. They are also much harder to treat than other types of breast cancer.
But a new finding from the lab of Professor Jill Bargonetti (Hunter College, The Graduate Center) has the potential to be a game-changer in how triple-negative breast cancer is treated. The study, published in Cancer Research, identified a curious feature of this type of cancer, one that could lead to the first targeted therapy for this hard-to-treat disease.
Cancers are classified as triple-negative when they test negative for three types of receptors found in other types of breast cancer: estrogen receptors, progesterone receptors, or a receptor called HER2. Breast cancer patients who test positive for these receptors can be treated with drugs that specifically target them, like tamoxifen. But these drugs don’t work with triple-negative cancers. Instead, triple-negative cancers are typically treated with some combination of surgery, chemotherapy, and radiation.
The new research from Bargonetti’s lab identified two proteins on replicating DNA in triple-negative breast cancers that are likely responsible for tumor growth. The proteins are mtp53, the mutant version of a protein that normally suppresses tumor growth, and a PARP protein, which in healthy people is important for DNA repair. The study found that these two proteins help triple-negative tumors grow.
By combing through existing cancer therapies, the researchers then identified two drugs — talazoparib and temozolomide — that might, in combination, treat these cancers. In fact, the researchers said this drug pairing could treat any breast cancer with a BRCA1 mutation, an inherited gene mutation that increases the risk of developing breast cancer and of breast cancer recurrence.
“This is an exciting finding because it could lead to the first targeted therapy for triple-negative breast cancer, enabling more precise and effective treatment of a very aggressive form of the disease,” Bargonetti told The Graduate Center.