title: Occult central nervous system involvement in patients with metastatic breast cancer: prevalence, predictive factors and impact on overall survival.
abstract: BACKGROUND
  As screening central nervous system (CNS) imaging is not routinely performed, the incidence and clinical relevance of occult CNS metastases in advanced breast cancer is unknown.
  
  
  METHODS
  All patients screened for participation in one of four clinical trials were included; each of the trials excluded patients with known CNS involvement and required screening CNS imaging. A cohort of breast cancer patients with symptomatic CNS metastases was identified from the IU Cancer Center Tumor Registry for comparison.
  
  
  RESULTS
  From November 1998 to August 2001, 155 screening imaging studies were performed. Twenty-three patients (14.8%) had occult CNS metastases. HER-2 overexpression (P = 0.02) and number of metastatic sites (P = 0.03) were predictive of CNS involvement by multivariate analysis. Median survival from time of metastasis (1.78 versus 2.76 years; P <0.0001) and from screening (4.67 versus 10.4 months; P = 0.0013) was shorter in patients with than without occult CNS metastasis. Survival among patients with occult CNS metastasis was similar to patients with symptomatic CNS disease.
  
  
  CONCLUSIONS
  Patients with CNS involvement, whether occult or symptomatic, have an impaired survival. Occult CNS metastasis is relatively common, but impact on survival of treating occult CNS disease in patients with progressive systemic metastases is questionable.
authors.affiliation: Division of Hematology and Oncology, Indiana University, Indianapolis, IN 46202, USA. kathmill@iupui.edu
authors.forename: K D
authors.initials: KD
authors.lastname: Miller
authors.forename: T
authors.initials: T
authors.lastname: Weathers
authors.forename: L G
authors.initials: LG
authors.lastname: Haney
authors.forename: R
authors.initials: R
authors.lastname: Timmerman
authors.forename: M
authors.initials: M
authors.lastname: Dickler
authors.forename: J
authors.initials: J
authors.lastname: Shen
authors.forename: G W
authors.initials: GW
authors.lastname: Sledge
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D001943:Breast Neoplasms / Q000473:pathology*; D016543:Central Nervous System Neoplasms / Q000556:secondary*; D002986:Clinical Trials as Topic; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008403:Mass Screening; D008875:Middle Aged; D011237:Predictive Value of Tests; D015995:Prevalence; D011379:Prognosis; D011446:Prospective Studies; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis; D012042:Registries / Q000706:statistics & numerical data*; D016019:Survival Analysis
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases