3 years. The median survival for patients with a diagnosis of an anaplastic astrocytoma is 2.8 years (reference: journal of neurosurgery. 2007 apr;106 (4):575-81.). The most important factor in determining the survival time period is the extent to which the tumor is removed surgically.
Not good. This is an aggressive brain tumor usually treated with surgery followed by radiotherapy or chemotherapy. Many cases relapse and five year survival rates are in the 25% range. Individual survival depends on surgical completeness, post surgery treatment, co-existing medical conditions, as well as chemotherapy given upon disease relapse.