Biomarker May Predict Lung Metastasis in Triple-Negative Breast Cancer

Researchers at Boston University School of Medicine (BUSM) have identified a biomarker that may help predict and direct treatment for basal-like breast cancer (BLBC).

This oftentimes deadly cancer can occur in women younger than age 40 and in the African American population, and is quick to spread to other organs. Also called triple-negative breast cancer, because it is estrogen receptor (ER)-negative, progesterone receptor (PR)-negative , and hormone epidermal growth factor (HER2)-negative, and thus doesn't respond to hormone therapies, it is even more difficult to treat once is has metastasized. Up until now, researchers have been unable to identify a target to help enhance treatment options.

The research team at BUSM partnered with the University of Cypress to compare biomarkers on the surface of cancer cells to the gene expression of breast tumors. This led to the discovery that a molecule named interleukin-13 receptor alpha 2 protein chain (IL-13Rα2) was prevalent in metastatic or late-stage BLBC.¹ Identifying specific markers for metastatic BLBC will further drug development and also aid in the prediction of patient survival.

This study was first reported in the July 25, 2015 online edition of Breast Cancer Research.²

In reviewing patient data, they were able to predict the likelihood of progression-free survival (PFS) based on whether the cancer cells had high levels of IL-13Rα2. The group also discovered that a subtype of BLBC that tended to spread to the lungs quickly had high IL13Rα2 levels. Targeted reduction of IL-13Rα2 resulted in suppression of lung metastasis formation in vivo. The research team believes that STAT6-dependent induction of tumor protein 63 (TP63) expression would suppress breast cancer cell migration.

The researchers conclude that IL-13Rα2 could be used as a biomarker to predict patient outcome, and provide a rationale for assessing the efficacy of anti- IL-13Rα2 therapies in some basal-like breast tumors to prevent metastatic disease.

References:

• Boston University Medical Center. (2015). Researchers identify new cancer marker and possible therapeutic target for breast cancer. EurekAlert!  
• Papageorgis P, Ozturk S, Lambert AW, et al. (2015). Targeting IL13Ralpha2 activates STAT6-TP63 pathway to suppress breast cancer lung metastasis. Breast Cancer Research, Jul 25;17(1):98.