Metastatic breast cancer—the most advanced stage of breast cancer, in which the cancer has spread to other parts of the body—isn’t considered a death sentence anymore, thanks to breakthrough discoveries in metastatic breast cancer treatment.
In a study conducted by the National Cancer Institute, researchers found that between 1992-1994 and 2005-2012, five-year relative survival among women initially diagnosed with metastatic breast cancer at ages 15-49 years doubled from 18% to 36%.
“More and more we’re seeing complete responses to therapy. That’s something that was previously unheard of for metastatic breast cancer,” says Amy Tiersten, MD, a hematologist and oncologist at the Mount Sinai Hospital in New York City. “That’s not true in every single case, but many patients with metastatic breast cancer can live good quantity and quality of lives—we have great treatment for it.”
How Metastatic Breast Cancer Treatments Have Improved
While metastatic breast cancer can’t be cured (the way many early-stage breast cancers can be) and is more difficult to treat than early-stage breast cancer, there are many treatment options for metastatic breast cancer available, such as chemotherapy, hormonal therapy, and targeted therapy.
“Amazing changes have happened in options for treatment for metastatic disease,” says Dr. Tiersten. “More and more we’re seeing complete responses to therapy. That’s something that was previously unheard of for metastatic breast cancer.”
Researchers have discovered certain characteristics that help cancer cells (or other cells near them) grow and thrive. This has led to the development of drugs that “target” these differences from normal cells, a class known as targeted therapy.
Targeted therapies are generally less likely than chemotherapy to harm normal, healthy cells. “Chemotherapy was the old gold standard we had to treat these patients with,” says Dr. Tiersten. “Chemotherapy is pretty course. You’re killing cancer cells, but you’re also killing normal cells.”
Targeted therapies are different, because they go after the cancer cells’ inner workings—what makes them different from normal, healthy cells—while leaving most healthy cells alone. These drugs tend to have side effects different from standard chemo drugs. Depending on the type of breast cancer, however, doctors may use targeted therapies along with chemotherapy for maximum effectiveness.
“The age of targeted therapies is really about understanding what pathways make a cancer cell proliferate more than a normal cell,” says Dr. Tiersten. “The medications that have been developed to target those specific pathways [are] absolutely incredible.”