A typical patient with a brain metastasis (BM) dies within an average of 8 months following the initial treatment of his or her brain tumor(s). Cause-specific mortality is rarely assessed or recorded, and the BM is often assumed to be the culprit.
Raymond Sawaya, MD; UT MD Anderson Cancer Center
Background:The diagnosis of a brain metastasis (BM) is usually a devastating one for patients and their families. Perceptions of major morbidity and impending mortality are widespread. Indeed, a typical patient with a BM dies within an average of 8 months following the initial treatment of his or her brain tumor(s). Cause-specific mortality is rarely assessed or recorded, and the BM is often assumed to be the culprit.
Methods: We reviewed data on patients with newly diagnosed BM treated with a resection or stereotactic radiosurgery at UT MD Anderson Cancer Center between June 1993 and May 2008. Out of a total of 2,170 patients, 1,931 (89%) died and 76 (3%) were lost to follow-up less than 5 years from treatment, and 163 (8%) were known to have survived 5 or more years from the date of initial BM treatment (long-term survival [LTS]). The 2,094 patients with known outcome were included in the study. Variables, such as patient age, functional status (assessed by the Karnofsky Performance Scale [KPS] score), primary cancer type, time lag between diagnosis of the primary and the BM, status of primary and extracranial systemic metastasis at the diagnosis of the BM, as well as factors related to BM, such as number of tumors, largest tumor volume, and worst tumor functional grade, were assessed. Of them, factors impacting long-term survival were sought out. Standard statistical methods were utilized. The study was conducted under an institutional review board (IRB)-approved protocol.
Results: The median age among the patients with LTS was 53 years (range: 17–77 yr), and 47% were male; 72% were symptomatic at the time of initial BM treatment, and 98% had a pretreatment KPS > 70. The primary cancer was lung in 30%, melanoma in 20%, breast in 18%, and renal in 11%. The interval from primary to diagnosis of BM was 14.3 months (range: 0.0–299.7 mo). Further, 77% had a stable primary or no evidence of disease at the time of treatment, with a recursive partitioning analysis (RPA) score of I in 59%. With regard to the BM, 31% were in eloquent brain areas and 41% were near eloquent areas. Single tumors were seen in 80% of patients, and two or three tumors were seen in 18%. The median largest tumor volume was 4.5 cm3 (range: 0.05–100.4 cm3). Seventy-one percent was treated with a resection. In the multivariate analysis, a KPS score > 70 was by far the factor most strongly associated with LTS, followed by a stable primary or no evidence of disease. Additional associations with treatment type and adjuvant radiation within subgroups of patients with specific characteristics at initiation of BM treatment will be presented.
Conclusions: Among patients with BM, there were long-term survivors in all typically unfavorable categories. However, good functional status was most strongly associated with LTS, followed by a nonprogressing primary. The use of modern and effective neurosurgical and radiosurgical techniques may have enabled BM patients with good functional status and a controlled primary to survive for a prolonged period of time.