MBC is the most advanced stage of breast cancer (stage IV) and occurs when cancer has spread beyond the breast to other parts of the body. Compared to early-stage breast cancer, the prognosis for stage IV breast cancer is generally poor, with the majority of breast cancer-related deaths resulting from complications of metastatic disease.

• MBC is cancer that has spread beyond the breast to other organs in the body
• More than 1 million new cases of breast cancer are diagnosed each year worldwide ACS
• Nearly one third of women with early-stage breast cancer will get MBC at some point in their lives
• Breast cancer is the second-leading cause of cancer-related death among women in the United States, and the leading cause of cancer death among women worldwide.

MBC remains essentially incurable and current goals of therapy are generally focused on relieving symptoms, delaying tumor progression, improving quality of life, and prolonging survival.