Breast cancers are tumors arising from abnormal cells of the breast. Metastatic breast cancer is cancer that has spread from the breast to another part of the body. So what is triple-negative breast cancer?
Over the past several years, advancements have been made in breast cancer research, including the discovery of the role of three proteins associated with breast cancer growth. These include estrogen receptors (ER), progesterone receptors (PR), and human epidermal growth factor receptor 2 (HER2). As a result of these discoveries, researchers have been successful in creating therapies specifically for those three proteins (“targeted therapy”). In patients diagnosed with triple-negative breast cancer, none of these proteins (ER, PR, HER2) are found on the tumor cells, eliminating the use of targeted therapies and making the disease more difficult to treat. In addition, triple-negative breast cancer is also typically categorized as a more aggressive disease and is more likely to recur than other subtypes of breast cancer. Researchers continue to look for additional tumor proteins that may help better target triple-negative breast cancer. gpNMB is one potentially useful target being researched.
gpNMB is a specific protein over-expressed in breast cancer and other tumor types that is believed to be involved in cancer growth and the spread of cancer to other body parts (Rose, 2010). Prior studies have shown that approximately 40% of women with triple-negative breast cancer have an increased amount of gpNMB on their cancer cells—making it a potential target for the development of new triple-negative breast cancer treatments (Rose, 2010). As a result of this potential, researchers are conducting the METRIC Study of an investigational drug called glembatumamab vedotin (CDX-011), which is designed to attach to gpNMB-containing cells, with the goal of killing the cancer cells.
BRCA1 and BRCA2 are human genes that produce certain types of proteins that inhibit cell growth. While the METRIC Study does not require participants to know their BRCA status, these are still important genes in breast cancer research. When functioning normally, BRCA1 and BRCA2 genes prevent the development of cancers. If you are born with a BRCA1 or BRCA2 gene mutation, you have an increased risk for developing breast, ovarian, and other cancers throughout your life, including a possibly higher risk for triple-negative breast cancer. Genetic tests can check for BRCA1 and BRCA2 mutations in people with a family history of cancer. If you are considering genetic testing, it is advised that you primarily talk to a genetic counselor, nurse, or doctor qualified to explain and interpret the results of these tests. Most large cancer centers have genetic counselors that can assess your risk of carrying a mutated BRCA gene, explain the risks and benefits of testing, and check with your insurance company to see if they will cover the cost (Cancer.org).
Doctors are conducting the METRIC Study to evaluate the safety and effectiveness of glembatumumab vedotin (CDX-011) in patients diagnosed with triple-negative breast cancer that has spread to other parts of the body. More than 250 patients with breast cancer or melanoma have received glembatumumab vedotin in prior research studies. Study results in both types of cancer support further testing of glembatumumab vedotin, particularly in patients with triple-negative breast cancer. If you have been diagnosed with triple-negative breast cancer that has spread beyond the original tumor, we hope that you will consider learning more about the METRIC Study. To find a study location near you to see if you may qualify, visit clinicaltrials.gov.
The information on this website is provided for educational purposes only and is not meant to be a substitute for the advice of a physician or other health care professional.