Abstract P6-11-12: CNS metastases in breast cancer: A comparison report
Authors: Bourdeanu L , Reilly AA , Luu T 
Published: August 2014

Background: Breast cancer is one of the most common causes of central nervous system (CNS) metastases, with 25-34% of patients experiencing brain metastases. Typically, CNS metastasis is associated with a dismal survival largely due to the inability of chemotherapeutic and biologic agents to cross the blood-brain barrier. In the last 5 to 7 years the management of CNS metastases utilizing targeted therapies, stereotactic radiation, and craniotomy have all shown to improve survival. We reviewed and analyzed data for CNS metastastic breast cancer treated at City of Hope (COH), a tertiary cancer center in California, in two cohorts between 2000-2005 and 2006-2011 to compare their survival.

Methods/Results: A retrospective, comparative, correlational chart review was performed. Data from 172 women diagnosed with CNS metastases between 2000 and 2011 at COH, was evaluated. There were 47 patients in 2000-2005 and 125 patients in 2006-2011. The sample consisted of Caucasians (49.7%), Hispanics (26.1%), Asians (16.8%), and African Americans (7.4%). The median age at CNS diagnosis was 53 years old (24-87). Of these patients 38.2% were Her2neu positive, 30.6% ER/PR positive, and 21.4% triple negative (TN). In this cohort, the median survival for all patients with brain metastases is 5 months (0.03-85.6 months). The survival with brain metastasis among Her2neu positive, TN, and ER/PR positive is significantly different (8 months, 2.5 months, and, 5.3 months, respectively, p&lt;0.0295). Limited sample size prevented the relatively substantial difference in patients with with Her2+ versus Her2- from reaching significance (median survival 8months vs 3.8 months respectively, p&lt;0.0939). The median survival for patients diagnosed and treated in 2006-2011 is statistically significantly worse than those in 2000-20005 (4.4 months and 7 months, respectively, p = 0.0042). Most patients received treatment for brain metastases with one or more therapies, including whole brain radiation, stereotactic radiation, craniotomy, and intrathecal chemotherapy. Most of the patients who received chemotherapy, craniotomy, and/or stereotactic radiation were in the 2006-2011 group (100%, 82.5%, and 72.6%, respectively).There was also a shift in the incidence of patients with TN, her2neu positive, and ER/PR positive disease in the 2006-2011 as compared to 2000-2005 (24% vs 14.6%, p&lt;0.004; 40% vs 31.3%, p&lt;0.000; 31.2% vs 29.2%, p 0.033, respectively).

Conclusion: The results of our study showed that despite the new therapies there was no change in survival for brain metastasis in breast cancer. In this single institution report, this may be in part due to an increase number of patients with TN and Her2neu positive CNS disease, better data collection, or due to better systemic control. We also noted an increase in the number of patients with brain metastases, which may be attributed to the increase in the number of patients presenting with metastatic breast cancer at COH for consideration of investigational therapies. Further studies aimed to determine why there is a shift in the tumor biology, as well as, to characterize risk factors for development of CNS disease and to develop new treatment strategies are warranted.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-11-12.