title: Central nervous system metastases in women who receive trastuzumab-based therapy for metastatic breast carcinoma.
abstract: BACKGROUND
  Women with HER-2 overexpressing metastatic breast carcinoma benefit from trastuzumab-based therapy, but trastuzumab does not cross the blood-brain barrier. The authors characterized central nervous system (CNS) disease in these women.
  
  
  METHODS
  Using pharmacy records, the authors retrospectively identified 153 women treated with trastuzumab alone or with chemotherapy for HER-2-positive metastatic breast carcinoma at Dana-Farber Partners Cancer Care from June 1998 to December 2000. A study cohort of 122 patients was identified after excluding patients without adequate clinical follow-up or who had CNS disease before trastuzumab treatment. Central nervous system disease was defined as one or more brain metastases or as leptomeningeal carcinomatosis. The median follow-up of this cohort was 23 months.
  
  
  RESULTS
  Central nervous system metastases were identified in 34% of patients (95% confidence interval, 26-44%) at a median of 16 months after diagnosis of metastatic breast carcinoma and 6 months from the beginning of trastuzumab therapy. Ninety-three percent of patients with CNS disease presented with clinical symptoms. Five percent of patients with CNS disease had leptomeningeal involvement alone, although 14% had leptomeningeal involvement and parenchymal brain metastases. Fifty percent of patients were responding or had stable disease while receiving trastuzumab at other disease sites at the time of diagnosis of CNS metastasis. The median survival period after CNS metastases was 13 months. Fifty percent of patients died of progressive CNS disease. Patients receiving trastuzumab as first-line therapy for metastatic disease frequently developed brain metastases while responding to or stable on trastuzumab at other disease sites.
  
  
  CONCLUSIONS
  Metastatic breast carcinoma to the CNS is common among patients receiving trastuzumab-based therapy, including patients responding to therapy outside the CNS. This may be due either to predilection for the CNS by HER-2-positive tumor cells and/or poor penetration of the CNS by trastuzumab or to improved visceral disease control leading to a longer life and onset of late tumor spread to the CNS. Efforts to characterize other risk factors for development of CNS disease, optimal screening algorithms, and new treatment strategies may be warranted.
authors.affiliation: Department of Adult Oncology, Dana Farber Cancer Institute, Boston, Massachusetts 02115, USA.
authors.forename: Johanna C
authors.initials: JC
authors.lastname: Bendell
authors.forename: Susan M
authors.initials: SM
authors.lastname: Domchek
authors.forename: Harold J
authors.initials: HJ
authors.lastname: Burstein
authors.forename: Lyndsay
authors.initials: L
authors.lastname: Harris
authors.forename: Jerry
authors.initials: J
authors.lastname: Younger
authors.forename: Irene
authors.initials: I
authors.lastname: Kuter
authors.forename: Craig
authors.initials: C
authors.lastname: Bunnell
authors.forename: Montse
authors.initials: M
authors.lastname: Rue
authors.forename: Rebecca
authors.initials: R
authors.lastname: Gelman
authors.forename: Eric
authors.initials: E
authors.lastname: Winer
mesh_terms: D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001932:Brain Neoplasms / Q000556:secondary*; D001943:Breast Neoplasms / Q000473:pathology* / Q000628:therapy*; D005260:Female; D006801:Humans; D008577:Meningeal Neoplasms / Q000556:secondary*; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases; D012189:Retrospective Studies; D012307:Risk Factors; D016019:Survival Analysis; D000068878:Trastuzumab
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab