title: Breast Malignancies in Children: Presentation, Management, and Survival.
abstract: OBJECTIVE
  Pediatric breast malignancies are rare, and descriptions in the literature are limited. The purpose of our study was to compare pediatric and adult breast malignancy.
  
  
  METHODS
  We performed a retrospective cohort study using the National Cancer Data Base comparing patients ≤21 years to those >21 years at diagnosis (1998-2012). Generalized linear models estimated differences in demographic, tumor, and treatment characteristics. Cox regression was used to compare overall survival.
  
  
  RESULTS
  Of 1,999,181 cases of invasive breast malignancies, 477 (0.02%) occurred in patients ≤21 years. Ninety-nine percent of adult patients had invasive carcinoma compared with 64.8% of pediatric patients with the remaining patients having sarcoma, malignant phyllodes, or malignancy not otherwise specified (p < 0.001). Pediatric patients were twice as likely to have an undifferentiated malignancy [relative risk (RR) 2.19; 95% confidence interval (CI) 1.72-3.79]. Half of adults presented with Stage I disease compared with only 22.7% of pediatric patients (p < 0.001). Pediatric patients were 40% more likely to have positive axillary nodes (RR 1.42; 95% CI 1.10-1.84). Among patients with invasive carcinoma, pediatric patients were more than four times as likely to receive a bilateral than a unilateral mastectomy compared with adults (RR 4.56; 95% CI 3.19-6.53). There was no difference in overall survival between children and adults.
  
  
  CONCLUSIONS
  Pediatric breast malignancies are more advanced at presentation, and there is variability in treatment practices. Adult and pediatric patients with invasive carcinoma have similar overall survival.
authors.affiliation: Department of Surgery, University of Washington, Seattle, WA, 98195, USA. morgan.richards@gmail.com.|Department of General and Thoracic Surgery, Seattle Children's Hospital, Seattle, WA, 98195, USA. morgan.richards@gmail.com.|Division of Pediatric General and Thoracic Surgery, Seattle Children's Hospital, Seattle, WA, 98105, USA. morgan.richards@gmail.com.
authors.forename: Morgan K
authors.initials: MK
authors.lastname: Richards
authors.affiliation: Department of General and Thoracic Surgery, Seattle Children's Hospital, Seattle, WA, 98195, USA.
authors.forename: Adam B
authors.initials: AB
authors.lastname: Goldin
authors.affiliation: University of Alabama, Birmingham, Birmingham, AL, 35233, USA.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Beierle
authors.affiliation: Methodist Children's Hospital of South Texas, San Antonio, TX, 78229, USA.
authors.forename: John J
authors.initials: JJ
authors.lastname: Doski
authors.affiliation: John Wayne Cancer Institute, Santa Monica, CA, 90404, USA.
authors.forename: Melanie
authors.initials: M
authors.lastname: Goldfarb
authors.affiliation: Maine Children's Cancer Program, Scarborough, ME, 04074, USA.
authors.forename: Monica
authors.initials: M
authors.lastname: Langer
authors.affiliation: Baylor College of Medicine, Houston, TX, 77030, USA.
authors.forename: Jed G
authors.initials: JG
authors.lastname: Nuchtern
authors.affiliation: Baylor College of Medicine, Houston, TX, 77030, USA.
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Vasudevan
authors.affiliation: Department of General and Thoracic Surgery, Seattle Children's Hospital, Seattle, WA, 98195, USA.
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Gow
authors.affiliation: Department of Surgery, University of Washington, Seattle, WA, 98195, USA.
authors.forename: Sara H
authors.initials: SH
authors.lastname: Javid
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000175:diagnosis / Q000401:mortality* / Q000628:therapy; D018270:Carcinoma, Ductal, Breast / Q000175:diagnosis / Q000401:mortality* / Q000628:therapy; D018275:Carcinoma, Lobular / Q000175:diagnosis / Q000401:mortality* / Q000628:therapy; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D019468:Disease Management; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011379:Prognosis; D012189:Retrospective Studies; D012509:Sarcoma / Q000175:diagnosis / Q000401:mortality* / Q000628:therapy; D015996:Survival Rate; D055815:Young Adult