We will not see a significant decrease in breast cancer mortality without a better understanding of breast cancer metastasis.
Women do not die of primary breast cancer. Over 90% of breast cancer deaths are due to the spread of the disease to other organs, such as bone, lungs, and brain. Approximately 155,000 women are living with metastatic breast cancer in the United States and this is projected to rise to 162,000 by the end of 2011, according to one expert. Close to one-third of the women considered "cured" of breast cancer will suffer recurrences and metastatic spread of the disease, often many years after their initial diagnosis. While researchers have identified treatments that sometimes shrink or slow metastatic tumors, such as estrogen blockers, radiation and chemotherapy, they are most often temporary. Treatments to eradicate metastasis do not exist.