title: Prognostic impact of metastatic pattern in stage IV breast cancer at initial diagnosis.
abstract: To analyze the prognostic influence of metastatic pattern (MP) compared with other biologic and clinical factors in stage IV breast cancer at initial diagnosis (BCID) and evaluate factors associated with specific sites of metastases (SSM).
  
  
  
  We evaluated women with stage IV BCID with known metastatic sites, reported to the Surveillance, Epidemiology and End Results program from 2010 to 2013. MP was categorized as bone-only, visceral, bone and visceral (BV), and other. Univariate and multivariate analyses determined the effects of each variable on overall survival (OS). Logistic regression examined factors associated with SSM.
  
  
  
  We included 9143 patients. Bone represented 37.5% of patients, visceral 21.9%, BV 28.8%, and other 11.9%. Median OS by MP was as follows: bone 38 months, visceral 21 months, BV 19 months, and other 33 months (P < 0.0001). Univariate analysis showed that higher number of metastatic sites had worse prognosis. In multivariate analysis, older age (hazard ratio 1.9), black race (hazard ratio 1.17), grade 3/4 tumors (hazard ratio 1.6), triple-negative (hazard ratio 2.24), BV MP (hazard ratio 2.07), and unmarried patients (hazard ratio 1.25) had significantly shorter OS. As compared with HR+/HER2- tumors, triple-negative and HR-/HER2+ had higher odds of brain, liver, lung, and other metastases. HR+/HER2+ had higher odds of liver metastases. All three subtypes had lower odds of bone metastases.
  
  
  
  There were substantial differences in OS according to MP. Tumor subtypes have a clear influence among other factors on SSM. We identified several prognostic factors that could guide therapy selection in treatment naïve patients.
authors.affiliation: Grupo Oncológico Cooperativo del Sur (GOCS), Neuquén, Argentina.
authors.forename: Bernardo Amadeo
authors.initials: BA
authors.lastname: Leone
authors.affiliation: Grupo Oncológico Cooperativo del Sur (GOCS), Neuquén, Argentina.
authors.forename: Carlos Teodoro
authors.initials: CT
authors.lastname: Vallejo
authors.affiliation: Grupo Oncológico Cooperativo del Sur (GOCS), Neuquén, Argentina.
authors.forename: Alberto Omar
authors.initials: AO
authors.lastname: Romero
authors.affiliation: Grupo Oncológico Cooperativo del Sur (GOCS), Neuquén, Argentina.
authors.forename: Mario Raúl
authors.initials: MR
authors.lastname: Machiavelli
authors.affiliation: Grupo Oncológico Cooperativo del Sur (GOCS), Neuquén, Argentina.
authors.forename: Juan Eduardo
authors.initials: JE
authors.lastname: Pérez
authors.affiliation: Grupo Oncológico Cooperativo del Sur (GOCS), Neuquén, Argentina.
authors.forename: Julieta
authors.initials: J
authors.lastname: Leone
authors.affiliation: University of Iowa Holden Comprehensive Cancer Center, Iowa City, IA, USA. jose-leone@uiowa.edu.|University of Iowa Hospitals and Clinics, C32 GH. 200 Hawkins Drive, Iowa City, IA, 52242, USA. jose-leone@uiowa.edu.
authors.forename: José Pablo
authors.initials: JP
authors.lastname: Leone
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000556:secondary; D001932:Brain Neoplasms / Q000556:secondary; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000453:epidemiology* / Q000401:mortality / Q000628:therapy; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D060787:Neoplasm Grading; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D011379:Prognosis; D012307:Risk Factors; D018426:SEER Program; D055815:Young Adult
keywords: Bone metastases; Brain metastases; Breast cancer; Metastatic pattern; Prognostic factors; Tumor subtype