Brain metastasis from brain cancer refers to the stage of cancer in which the breast cancer has spread from the breast to the brain. Brain metastasis is the leading cause of death in breast cancer patients. According to the director of breast cancer research program at the Sarah Cannon Research Institute in Nashville, Tennessee, brain metastasis affects 30 percent of women diagnosed with breast cancer.
There are two forms of breast cancer: HER-2-positive and HER-2-negative. In HER-2-positive breast cancer, the patient tests positive for the human epidermal growth factor receptor-2, while HER-2-negative breast cancer patients do not test positive for the hormone. However, both HER-2-negative and HER-2-positive breast cancer patients can experience brain metastasis. The life expectancy depends on which form of breast cancer the patient has.
In a Texas study of 1,000 women with HER-2-positive breast cancer brain metastasis, the average survival time was given at 13.9 months. This time period includes time after the brain metastasis has been discovered by medical personnel. In a Massachusetts study conducted by 83 breast cancer brain metastasis patients, the HER-2-positive group experienced a life expectancy of 17.1 months after diagnosis.
Compared to the survival of HER-2-Positive breast cancer patients, the life expectancy of HER-2-negative patients is short. In the same Massachusetts study in which the HER-2-positive group lived for an additional 17.1 months, HER-2-negative patients' average survival was only 5.2 months.
Whether a patient is positive or negative for HER-2 is a defining factor in the life expectancy for breast cancer brain metastasis. Other factors that can influence the survival rate include the amount of metastases and the other diseases the patient may have. The spread of the metastases into the central nervous system can cause other problems, which ultimately lead to a shorter lifespan.
Breast cancer can be reoccurring. Each time the cancer is treated and reoccurs, the patient should be re-tested for the presence of HER-2. This will affect the treatment options regardless of whether the breast cancer spreads to brain metastasis. However, a diagnosis of breast cancer brain metastasis is not an automatic death sentence. A French study conducted over a 14-year period and ending in 1993 found up to 44 percent of patients living three years or longer after being diagnosed.