title: Identifying risk factors for brain metastasis in breast cancer patients: Implication for a vigorous surveillance program.
abstract: OBJECTIVE
  Brain metastasis occurs in 10-15% of metastatic breast cancer patients and is associated with poor prognosis. This study aims to identify tumor characteristics of primary breast cancer, which are related to brain metastases in Hong Kong Chinese patients.
  
  
  METHODS
  A retrospective study of patients with invasive breast cancer receiving treatment in a university hospital from January 2001 to December 2008 was performed. The clinicopathological factors of patients with brain metastases were analyzed and compared with those who had no brain metastasis. Risk factors for brain metastasis were identified by univariate analysis first and then by multivariate analysis.
  
  
  RESULTS
  A total of 912 patients with invasive breast cancer were treated during the study period. Of these, 30 patients were found to have distant metastases to brain. Patients with brain metastases had more breast tumors of higher histological grade (Grade III, 78.9% vs. 30.2%; p = 0.001). Their tumors also had a significantly higher rate of negative estrogen receptors (78.9% vs. 30.2%, p = 0.001). On multivariate analysis, only high tumor grading was found to be predictive of developing brain metastasis.
  
  
  CONCLUSIONS
  Chinese breast cancer patients with brain metastasis were more likely to have high-grade tumors and negative estrogen receptor status. A more vigorous surveillance program for the central nervous system should be considered for this group of patients.
authors.affiliation: Division of Breast Surgery, Department of Surgery, The University of Hong Kong, Pok Fu Lam, Hong Kong.
authors.forename: Lorraine
authors.initials: L
authors.lastname: Chow
authors.affiliation: Division of Breast Surgery, Department of Surgery, The University of Hong Kong, Pok Fu Lam, Hong Kong.
authors.forename: Dacita
authors.initials: D
authors.lastname: Suen
authors.affiliation: Division of Breast Surgery, Department of Surgery, The University of Hong Kong, Pok Fu Lam, Hong Kong.
authors.forename: Kwok Kuen
authors.initials: KK
authors.lastname: Ma
authors.affiliation: Division of Breast Surgery, Department of Surgery, The University of Hong Kong, Pok Fu Lam, Hong Kong. Electronic address: avakwong@hku.hk.
authors.forename: Ava
authors.initials: A
authors.lastname: Kwong
mesh_terms: D000293:Adolescent; D000328:Adult; D000359:Aftercare; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D001932:Brain Neoplasms / Q000175:diagnosis / Q000209:etiology / Q000401:mortality / Q000556:secondary*; D001943:Breast Neoplasms / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006723:Hong Kong; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D060787:Neoplasm Grading; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D012189:Retrospective Studies; D012307:Risk Factors; D016019:Survival Analysis; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases
keywords: HER2; brain metastasis; breast cancer; trastuzumab; whole-brain irradiation