BACKGROUND: Discordance in hormone receptors (HR) and @entity1 @entity1722 ( @entity1722 ) status between primary @entity5 and metastatic sites for @entity0 is well established. However, it is uncertain which @entity1 -related factors lead to biopsy when @entity3 are suspected and whether having a biopsy impacts survival. METHODS: The medical charts of @entity0 ( @entity0 ) @entity1 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 @entity1722 . Both bivariate and multivariate analyses were performed to assess @entity1 characteristics related to biopsy and whether having a biopsy was associated with improved survival. RESULTS: Of 409 @entity1 suspected of having @entity0 , 165 (40%) had a biopsy, and 34% of these had discordant HR or @entity1722 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+/ @entity1722 -, or missing HR/ @entity1722 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: @entity1 with missing HR and @entity1722 data at initial diagnosis (p   =   0.001), those without @entity3 in liver, lung or brain (p   =   0.001), and being younger than 70  years old at recurrence (p   <   0.001). CONCLUSIONS: Specific clinical factors were associated with biopsy at the time of suspected recurrence. Having a biopsy was associated with reduced mortality.

Biopsy of @entity0 @entity3 : XXXX characteristics and survival.

@entity1 :: ('9606', 'Species') :: ['human', 'patients', 'patient'] @entity0 :: ('MESH:D001943', 'Disease') :: ['breast cancer', 'metastatic breast cancer', 'MBC'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumors'] @entity3 :: ('MESH:D009362', 'Disease') :: ['metastases'] @entity1722 :: ('2064', 'Gene') :: ['epidermal growth factor receptor 2', 'HER2']
@entity1 :: (9606,Species) :: ['patient']
