Stage four breast cancer is diagnosed when distant metastasis is found, normally in the bone, brain, liver or lungs. One to 2 percent of women are diagnosed at this stage, although a study at the University of North Carolina reported in the October 2008 issue of "Academic Radiology" revealed that being uninsured increased the chance of being initially diagnosed at a late stage by 66 percent. Effecting a cure with chemotherapy and radiation is not expected at this stage, but increasingly women are treating their stage four breast cancer as a chronic health problem.
Five-Year Survival Rates
The five-year survival rate for stage four breast cancer is said to be 20 percent, according to the National Cancer Institute's Surveillance, Epidemiology, and End Results database. This figure was based on women who were diagnosed with breast cancer between 1988 and 2001. It does not differentiate women who are treated at comprehensive cancer centers from those who stop all active treatment, nor does it separate the prognosis of those women who are otherwise fit and healthy from those who also are obese or challenged by other health threats.
Characteristics of Long-Term Survivors
People whose stage four status is based on a single site of metastasis that can be removed surgically or destroyed with radiation therapy should be considered candidates for curative treatment according to Gabriel N. Hortobagyi, M.D., of the M.D. Anderson Cancer Center. Being young, otherwise healthy and physically active at the time of diagnosis were found to be the characteristics of long-term stage four survivors, Horobagyi notes.
Living in a state of overall health allows people to take advantage of treatment options that are more aggressive. This involves a lifetime of preventing obesity, diabetes, cardiovascular disease and damage to the liver and kidneys.
Effect of Blood Test Results
When a person is diagnosed with stage four breast cancer, blood tests may help determine whether the prognosis for continued short-term survival is good or poor. Researchers at the Department d'Oncologie at the Institute Curie compared the prognostic value of finding tumor cells circulating in blood and the presence of tumor cells in bone marrow, and it was found that the former is both less invasive, less painful and more effective in determining how long an individual patient will survive with this cancer. This testing is called Circulating Tumor Cell Analysis or CTC.
Effect of Tumor Characteristics
The difference between the prognosis given to two people with stage four breast cancer who are approximately the same age and have the same general health status may be found in an examination of the tumors each one had removed at the time of their original diagnosis.
The grade of the tumor indicates how much the cancer cells resemble normal breast cells. A tumor with a highly malignant grade generally indicates a poorer prognosis. So does a tumor that is not well differentiated and with borders that blend into the surrounding tissue.
Breast tumor tissue is tested for the presence of the hormone receptive cells including estrogen receptors, progesterone receptors, and the HER2 tumor marker.
Tumors that are estrogen and/or progesterone dependent may respond well to hormone antagonist treatment such as Femera, improving the prognosis, and the National Cancer Institute reports that they will have a longer disease-free survival period and a longer time before progression of the disease if a selective aromatase inhibitor is administered along with drug used to block estrogen and/or progestin. This protocol does not, however, affect the overall five-year survival rate.
HER 2 Influence
The 25 percent of breast cancer patients with many HER 2 receptors, sites on their tumors that were actively seeking this hormone, have a poor prognosis, according to the National Comprehensive Cancer Network but a specific treatment offers some of them hope. The National Cancer institute notes that 21 percent of women at stage four who have HER2 positive tumors responded to the monoclonal antibody, Trastuzumab. Their cancers stabilized for a longer than expected period of time and they enjoyed a longer disease-free period though the chance of surviving five years was not affected.