title: Pretreatment clinical prognostic factors for brain metastases from breast cancer treated with Gamma Knife radiosurgery.
abstract: BACKGROUND
  Brain metastases significantly affect morbidity and mortality rates for patients with metastatic breast cancer. Treatment for brain metastases lengthens survival, and options such as stereotactic radiosurgery (SRS) can increase survival to 12 months or longer. This study retrospectively analyzes the prognostic factors for overall survival (OS) for patients with one or multiple brain metastases from breast cancer treated with SRS.
  
  
  METHODS
  Between December 2001 and May 2015, 111 patients with brain metastases from breast cancer were grouped by potential prognostic factors including age at diagnosis, Karnofsky Performance Status (KPS) score, number of brain metastases, and whether or not they received adjuvant treatments such as whole brain radiotherapy (WBRT) or surgical resection. Survival rates were determined for all groups, and hazard ratios were calculated using univariate and multivariate analyses to compare differences in OS.
  
  
  RESULTS
  Median OS was 16.8 ± 4.22 months. Univariate analysis of patients with a KPS ≤60 and multivariate analysis of KPS 70-80 showed significantly shorter survival than those with KPS 90-100 (5.9 ± 1.22 months, 21.3 ± 11.69 months, and 22.00 ± 12.56 months,P= 0.024 and < 0.001). Other results such as age ≥65 years and higher number of brain metastases trended toward shorter survival but were not statistically significant. No difference in survival was found for patients who had received WBRT in addition to SRS (P= 0.779).
  
  
  CONCLUSIONS
  SRS has been shown to be safe and effective in treating brain metastases from breast cancer. We found our median survival to be 16.8 ± 4.22 months, an increase from other clinical reports. In addition, 38.4% of our population was alive at 2 years and 15.6% survived 5 years. Significant prognostic factors can help inform clinical treatment decisions. This study found that KPS was a significant prognostic indicator of OS in these patients.
authors.affiliation: Gamma Knife of Spokane, 910 W 5 Ave, Suite 102, Spokane, WA 99204, USA; University of Washington School of Medicine, 1959 NE Pacific St, Seattle, WA 98195, USA.
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Roehrig
authors.affiliation: Gamma Knife of Spokane, 910 W 5 Ave, Suite 102, Spokane, WA 99204, USA; University of Washington School of Medicine, 1959 NE Pacific St, Seattle, WA 98195, USA.
authors.forename: Ethan A
authors.initials: EA
authors.lastname: Ferrel
authors.affiliation: Gamma Knife of Spokane, 910 W 5 Ave, Suite 102, Spokane, WA 99204, USA; Cancer Care Northwest, 910 W 5 Ave, Suite 102, Spokane, WA 99204, USA.
authors.forename: Devon A
authors.initials: DA
authors.lastname: Benincosa
authors.affiliation: Gamma Knife of Spokane, 910 W 5 Ave, Suite 102, Spokane, WA 99204, USA.
authors.forename: Alexander R
authors.initials: AR
authors.lastname: MacKay
authors.affiliation: Inland Neurosurgery and Spine Associates, 105 W 8 Ave, Suite 200, Spokane, WA 99204, USA.
authors.forename: Benjamin C
authors.initials: BC
authors.lastname: Ling
authors.affiliation: Gamma Knife of Spokane, 910 W 5 Ave, Suite 102, Spokane, WA 99204, USA; Inland Neurosurgery and Spine Associates, 105 W 8 Ave, Suite 200, Spokane, WA 99204, USA.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Carlson
authors.affiliation: Gamma Knife of Spokane, 910 W 5 Ave, Suite 102, Spokane, WA 99204, USA; Department of Neurosurgery, Rockwood Clinic, 801 W 5 Ave, Suite 525, Spokane, WA 99204, USA.
authors.forename: John J
authors.initials: JJ
authors.lastname: Demakas
authors.affiliation: Gamma Knife of Spokane, 910 W 5 Ave, Suite 102, Spokane, WA 99204, USA; Cancer Care Northwest, 910 W 5 Ave, Suite 102, Spokane, WA 99204, USA.
authors.forename: Aaron
authors.initials: A
authors.lastname: Wagner
authors.affiliation: Gamma Knife of Spokane, 910 W 5 Ave, Suite 102, Spokane, WA 99204, USA; Cancer Care Northwest, 910 W 5 Ave, Suite 102, Spokane, WA 99204, USA.
authors.forename: Wayne T
authors.initials: WT
authors.lastname: Lamoreaux
authors.affiliation: Gamma Knife of Spokane, 910 W 5 Ave, Suite 102, Spokane, WA 99204, USA; Cancer Care Northwest, 910 W 5 Ave, Suite 102, Spokane, WA 99204, USA.
authors.forename: Robert K
authors.initials: RK
authors.lastname: Fairbanks
authors.affiliation: Cancer Care Northwest, 910 W 5 Ave, Suite 102, Spokane, WA 99204, USA.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Call
authors.affiliation: Gamma Knife of Spokane, 910 W 5 Ave, Suite 102, Spokane, WA 99204, USA.
authors.forename: Barton S
authors.initials: BS
authors.lastname: Cooke
authors.affiliation: DataWorks Analytics, LLC, 3952 N Magnuson St, Coeur D'Alene, ID 83815, USA.
authors.forename: Ben
authors.initials: B
authors.lastname: Peressini
authors.affiliation: Gamma Knife of Spokane, 910 W 5 Ave, Suite 102, Spokane, WA 99204, USA; Cancer Care Northwest, 910 W 5 Ave, Suite 102, Spokane, WA 99204, USA.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Lee
keywords: Brain metastases; breast cancer; stereotactic radiosurgery