mBC & Existing
treatment options

What to ask your

Diagnosis and
the next step

“What to Ask Your Doctor” Guide

Metastatic breast cancer

Metastatic breast cancer also called stage IV or advanced breast cancer, is breast cancer that has spread to another part of the body, most commonly the bones, lungs, brain, or liver. The process of cancer spreading is called metastasis. Metastasis happens when cancer cells break away from the original tumor in the breast and travel to other parts of the body. These cancer cells travel through the bloodstream or the lymphatic system.1 Approximately 30% of women diagnosed with early-stage breast cancer may develop metastatic disease. Some people have metastatic breast cancer when they are first diagnosed with breast cancer.2