title: Poorer survival outcomes for male breast cancer compared with female breast cancer may be attributable to in-stage migration.
abstract: BACKGROUND
  Male breast cancer accounts for less than 1% of all breast cancers, yet males have a worse prognosis than females with breast cancer.
  
  
  METHODS
  Using the 1988-2003 Surveillance, Epidemiology, and End Results Program data, we conducted a retrospective, population-based cohort study to investigate stage-specific differences in breast cancer-specific and all-cause mortality between males and females. We calculated adjusted hazard ratios (aHR) and 95% confidence intervals (CI) using Cox regression models to compare breast cancer-specific and all-cause mortality by stage between males and females, controlling for potential confounding variables.
  
  
  RESULTS
  There were 246,059 patients with a first, single, primary breast cancer [1,541 (0.6%) male; 244,518 (99.4%) female]. Compared with females, males were more likely to be older, Black, married, diagnosed at more advanced stages, and treated with mastectomy (each P < 0.001). Males also were more likely to have lower grade and estrogen/progesterone receptor-positive tumors (each P < 0.001). After controlling for confounders, males were more likely to die from their breast cancer when compared with females, only if diagnosed with stage I disease (aHR 1.72, CI 1.15-2.61). For all-cause mortality, males were more likely than females to die at each stage of disease except stage IV.
  
  
  CONCLUSIONS
  Although all-cause mortality was higher for men than women at all stages of nonmetastatic breast cancer, higher male breast cancer-specific mortality was attributed to poorer survival in stage I disease. However, this statistical difference is unlikely to be clinically relevant and attributable to in-stage migration.
authors.affiliation: Department of Surgery, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Gnerlich
authors.forename: Anjali D
authors.initials: AD
authors.lastname: Deshpande
authors.forename: Donna B
authors.initials: DB
authors.lastname: Jeffe
authors.forename: Susmitha
authors.initials: S
authors.lastname: Seelam
authors.forename: Eric
authors.initials: E
authors.lastname: Kimbuende
authors.forename: Julie A
authors.initials: JA
authors.lastname: Margenthaler
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000453:epidemiology / Q000401:mortality* / Q000473:pathology*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000453:epidemiology / Q000401:mortality* / Q000473:pathology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D055815:Young Adult