title: Outcomes and prognostic factors in women with 1 to 3 breast cancer brain metastases treated with definitive stereotactic radiosurgery.
abstract: BACKGROUND
  With the continuing increase in the use of definitive stereotactic radiosurgery (SRS) for patients with limited brain metastases (BM), clinicians need more specific prognostic tools. We investigated clinical predictors of outcomes in patients with limited breast cancer BM treated with SRS alone.
  
  
  METHODS
  We identified 136 patients with breast cancer and 1-3 BM who underwent definitive SRS for 186 BM between 2000 and 2012. The Kaplan-Meier method was used to assess overall survival (OS), regional failure (RF), and local failure (LF). Associations between clinical factors and outcomes were tested using Cox regression. A point scoring system was used to stratify patients based on OS, and the predictive power was tested with concordance probability estimate (CPE).
  
  
  RESULTS
  The median OS was 17.6 months. The 12-month RF and LF rates were 45% and 10%, respectively. On multivariate analysis, >1 lesion (hazard ratio [HR] = 1.6, P=.02), triple-negative (TN) disease (HR=2.0, P=.006), and active extracranial disease (ED) (HR=2.7, P<.0001) were significantly associated with worse OS. The point score system was defined using proportional simplification of the multivariate Cox proportional hazards regression function. The median OS for patients with 3.0-4.0 points (n=37), 4.5-5.5 points (n=28), 6.0-6.5 points (n=37), and 8-8.5 points (n=34) were 9.2, 15.6, 25.1, and 45.1 months, respectively (P<.0001, CPE = 0.72). Active ED (HR=2.4, P=.0007) was significantly associated with RF. Higher risk for LF was significantly associated with larger BM size (HR=3.1, P=.0001).
  
  
  CONCLUSIONS
  Patients with >1 BM, active ED, and TN had the highest risk of death after SRS. Active ED is an important prognostic factor for OS and intracranial control.
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: T Jonathan
authors.initials: TJ
authors.lastname: Yang
authors.affiliation: Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Jung Hun
authors.initials: JH
authors.lastname: Oh
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Folkert
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Gaorav
authors.initials: G
authors.lastname: Gupta
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Weiji
authors.initials: W
authors.lastname: Shi
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Medical Oncology, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Aki
authors.initials: A
authors.lastname: Morikawa
authors.affiliation: Department of Medical Oncology, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Andrew
authors.initials: A
authors.lastname: Seidman
authors.affiliation: Department of Neurosurgery, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Cameron
authors.initials: C
authors.lastname: Brennan
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Yamada
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Chan
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York. Electronic address: BealK@MSKCC.org.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Beal
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000401:mortality / Q000473:pathology / Q000556:secondary* / Q000601:surgery*; D001943:Breast Neoplasms / Q000737:chemistry / Q000473:pathology; D005260:Female; D006801:Humans; D017567:Karnofsky Performance Status; D008875:Middle Aged; D011379:Prognosis; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods* / Q000401:mortality; D012044:Regression Analysis; D016019:Survival Analysis; D016896:Treatment Outcome; D047368:Tumor Burden; D055815:Young Adult