title: Prospective study evaluating the impact of tissue confirmation of metastatic disease in patients with breast cancer.
abstract: OBJECTIVE
  Decisions about treatment for women with metastatic breast cancer are usually based on the estrogen (ER), progesterone (PgR), and human epidermal growth factor receptor 2 (HER2) status of the primary tumor. Retrospective data suggest that discordance between primary and metastatic lesions leads to detrimental outcome. This prospective study investigated receptor status of primary tumors and metastases in the same patient and assessed the impact of discordance on patient management and survival.
  
  
  METHODS
  Biopsies of suspected metastases were analyzed for ER, PgR, and HER2. Primary tumors and metastases were analyzed using similar methodology. The treating oncologist indicated a treatment plan before and after biopsy to determine whether the result influenced management. Patients were followed up for progression or death.
  
  
  RESULTS
  Of 121 women undergoing biopsy, 80% could be analyzed for receptor status. Discordance in ER, PgR, and HER2 between the primary and the metastasis was 16%, 40%, and 10%, respectively. Biopsy led to a reported change of management in 14% of women (95% CI, 8.4% to 21.5%). Fine-needle aspiration and biopsy of bone led to reduced ability to analyze receptors. After a median follow-up of 12 months, there were no trends for an association between receptor discordance and either time to treatment failure or overall survival.
  
  
  CONCLUSIONS
  Biopsy of metastases is technically feasible. Clinicians alter immediate management in one of seven patients on the basis of results of the biopsy, and discordance is not then associated with detrimental effects on outcome. Tissue confirmation should be considered in women with breast cancer and suspected metastatic recurrence.
authors: Division of Medical Oncology, Princess Margaret Hospital, 610 University Ave, Toronto, ON M5G 2M9, Canada. eitan.amir@uhn.on.ca
authors: Eitan
authors: E
authors: Amir
authors: Naomi
authors: N
authors: Miller
authors: William
authors: W
authors: Geddie
authors: Orit
authors: O
authors: Freedman
authors: Farrah
authors: F
authors: Kassam
authors: Christine
authors: C
authors: Simmons
authors: Maria
authors: M
authors: Oldfield
authors: George
authors: G
authors: Dranitsaris
authors: George
authors: G
authors: Tomlinson
authors: Andreas
authors: A
authors: Laupacis
authors: Ian F
authors: IF
authors: Tannock
authors: Mark
authors: M
authors: Clemons
mesh_terms: D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism*; D005260:Female; D006801:Humans; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D000068878:Trastuzumab
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab