Breast cancers are assigned to 1 of 4 stages at the time of initial diagnosis and treatment. Stage is determined by the size of the cancer and whether it has spread to lymph nodes under the arm or to more distant parts of the body. Stage 4 breast cancer has spread to distant organs or sites, such as the lungs, liver, brain or bones.

5-Year Survival and Average Length of Life in Stage 4 Breast Cancer

Among all women with stage 4 breast cancer, approximately 20 percent will be alive 5 years after diagnosis, according to data collected by the National Cancer Institute. Approximately 50 percent of women with stage 4 breast cancer are alive 18 months after diagnosis.

Factors That Affect Life Expectancy

Life expectancy in stage 4 breast cancer is improving slowly but steadily. Combination treatment with surgery, radiation, multiple medications and better supportive care have made positive contributions. In the 30 years ending in 2000, 1-year survival, 3-year survival and average length of life improved approximately 30 percent in women with stage 4 breast cancer 1. Data published in January 2004 in the journal "Cancer" from M.D. Anderson Cancer Center support these findings, as does an August 2004 report published in the Journal of Clinical Oncology from 3 breast cancer centers in France 3. Most of the improvements were observed in non-Hispanic white women; African-American women experienced little or no improvement in survival. Other factors that decrease life expectancy include poor access to health care, intolerance of chemotherapy drugs, obesity and cancers that are not sensitive to estrogen and progesterone.