Lung cancer with brain metastasis typically has a life expectancy of a few months, according to OncoLink. If multiple tumors exist in the brain, the cancer is usually incurable, as the tumors come back with time.
Regardless of the type of primary cancer, patients with untreated brain metastases or those treated only with corticosteroids have a median survival rate of one month, notes the International RadioSurgery Association. The most commonly used treatment for brain metastasis is whole brain radiation therapy, which gives patients a three- to four-month survival rate. This treatment usually fails because most tumors that metastasize to the brain are resistant to radiation therapy. Those who survive for a longer period of time are at a high risk of developing radiation-induced dementia.
Surgery to remove cancer lesions enhances the survival rate to 10 months if followed by whole brain radiation therapy, explains IRSA. However, risks of surgery include operative mortality and patients developing post-surgical medical conditions. Radiosurgery, a technique that involves a single high dose of radiation, is not a primary therapy, despite the fact that the median survival rate of using it alone is nine months.
Researchers are studying new and improved treatment options for secondary brain tumors as of 2015, according to Cancer Research UK.