title: Biopsy of breast cancer metastases: patient characteristics and survival.
abstract: Discordance in hormone receptors (HR) and human epidermal growth factor receptor 2 (HER2) status between primary tumors and metastatic sites for breast cancer is well established. However, it is uncertain which patient-related factors lead to biopsy when metastases are suspected and whether having a biopsy impacts survival.
  
  
  
  The medical charts of metastatic breast cancer (MBC) patients diagnosed January 2000-August 2014 were retrospectively reviewed. A biopsy was defined as a procedure where tissue was obtained and assessed for both HR and HER2. Both bivariate and multivariate analyses were performed to assess patient characteristics related to biopsy and whether having a biopsy was associated with improved survival.
  
  
  
  Of 409 patients suspected of having MBC, 165 (40%) had a biopsy, and 34% of these had discordant HR or HER2 status when compared to the initial diagnosis. In multivariate analysis, having a biopsy was associated with: recurrence in years 2010-2014, disease-free interval of > =3 years, stage 0-IIA at presentation, suspected locoregional recurrence, being HR+/HER2-, or missing HR/HER2 at diagnosis. A similar multivariate analysis revealed that having a biopsy was associated with improved survival (HR = 0.67, p = 0.002). The association of biopsy and improved survival was noted in specific subgroups: patients with missing HR and HER2 data at initial diagnosis (p = 0.001), those without metastases in liver, lung or brain (p = 0.001), and being younger than 70 years old at recurrence (p < 0.001).
  
  
  
  Specific clinical factors were associated with biopsy at the time of suspected recurrence. Having a biopsy was associated with reduced mortality.
authors.affiliation: Division of Oncology, Rambam Health Care Campus, Haifa, Israel.
authors.forename: Shlomit Strulov
authors.initials: SS
authors.lastname: Shachar
authors.affiliation: Statistical Department, Rambam Health Care Campus, Haifa, Israel.
authors.forename: Tanya
authors.initials: T
authors.lastname: Mashiach
authors.affiliation: Division of Oncology, Rambam Health Care Campus, Haifa, Israel.
authors.forename: Georgeta
authors.initials: G
authors.lastname: Fried
authors.affiliation: Division of Oncology, Rambam Health Care Campus, Haifa, Israel.
authors.forename: Karen
authors.initials: K
authors.lastname: Drumea
authors.affiliation: Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
authors.forename: Noa
authors.initials: N
authors.lastname: Shafran
authors.affiliation: University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Hyman B
authors.initials: HB
authors.lastname: Muss
authors.affiliation: Division of Oncology, Rambam Health Care Campus, Haifa, Israel. g_barsela@rambam.health.gov.il.|Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel. g_barsela@rambam.health.gov.il.|Integrated Oncology and Palliative Care Unit, Rambam Health Care Campus, POB 9602, Haifa, 31096, Israel. g_barsela@rambam.health.gov.il.
authors.forename: Gil
authors.initials: G
authors.lastname: Bar-Sela
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local / Q000378:metabolism / Q000473:pathology*; D009367:Neoplasm Staging; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D012189:Retrospective Studies; D016019:Survival Analysis
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human
keywords: Biopsy; Breast carcinoma; Pathology; Recurrent-metastatic disease; Survival