title: Prospective observational study of breast cancer treatment outcomes for UK women aged 18-40 years at diagnosis: the POSH study.
abstract: BACKGROUND
  Breast cancer at a young age is associated with poor prognosis. The Prospective Study of Outcomes in Sporadic and Hereditary Breast Cancer (POSH) was designed to investigate factors affecting prognosis in this patient group.
  
  
  METHODS
  Between 2000 and 2008, 2956 patients aged 40 years or younger were recruited to a UK multicenter prospective observational cohort study (POSH). Details of tumor pathology, disease stage, treatment received, and outcome were recorded. Overall survival (OS) and distant disease-free interval (DDFI) were assessed using Kaplan-Meier curves. All statistical tests were two-sided.
  
  
  RESULTS
  Median age of patients was 36 years. Median tumor diameter was 22 mm, and 50% of patients had positive lymph nodes; 59% of tumors were grade 3, 33.7% were estrogen receptor (ER) negative, and 24% were human epidermal growth factor receptor 2 (HER2) positive. Five-year OS was higher for patients with ER-positive than ER-negative tumors (85.0%, 95% confidence interval [CI] = 83.2% to 86.7% vs 75.7%, 95% CI = 72.8% to 78.4%; P < .001), but by eight years, survival was almost equal. The eight-year OS of patients with ER-positive tumors was similar to that of patients with ER-negative tumors in both HER2-positive and HER2-negative subgroups. The flexible parametric survival model for OS shows that the risk of death increases steadily over time for patients with ER-positive tumors in contrast to patients with ER-negative tumors, where risk of death peaked at two years.
  
  
  CONCLUSIONS
  These results confirm the increased frequency of ER-negative tumors and early relapse in young patients and also demonstrate the equally poor longer-term outlook of young patients who have ER-positive tumors with HER2-negative or -positive disease.
authors.affiliation: Cancer Sciences Academic Unit and University of Southampton Clinical Trials Unit, Faculty of Medicine, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.
authors.forename: Ellen
authors.initials: E
authors.lastname: Copson
authors.forename: Bryony
authors.initials: B
authors.lastname: Eccles
authors.forename: Tom
authors.initials: T
authors.lastname: Maishman
authors.forename: Sue
authors.initials: S
authors.lastname: Gerty
authors.forename: Louise
authors.initials: L
authors.lastname: Stanton
authors.forename: Ramsey I
authors.initials: RI
authors.lastname: Cutress
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Altman
authors.forename: Lorraine
authors.initials: L
authors.lastname: Durcan
authors.forename: Peter
authors.initials: P
authors.lastname: Simmonds
authors.forename: Gill
authors.initials: G
authors.lastname: Lawrence
authors.forename: Louise
authors.initials: L
authors.lastname: Jones
authors.forename: Judith
authors.initials: J
authors.lastname: Bliss
authors.forename: Diana
authors.initials: D
authors.lastname: Eccles
mesh_terms: D000328:Adult; D000367:Age Factors; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000032:analysis; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D002277:Carcinoma / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D017024:Chemotherapy, Adjuvant; D015331:Cohort Studies; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D020360:Neoadjuvant Therapy / Q000379:methods; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis; D011960:Receptors, Estrogen / Q000032:analysis; D013629:Tamoxifen / Q000008:administration & dosage; D000068878:Trastuzumab; D016896:Treatment Outcome; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D013629:Tamoxifen; D000068878:Trastuzumab; C508053:ERBB2 protein, human