title: Age at diagnosis in relation to survival following breast cancer: a cohort study.
abstract: BACKGROUND
  Age is an important risk factor for breast cancer, but previous data has been contradictory on whether patient age at diagnosis is also related to breast cancer survival. The present study evaluates age at diagnosis as a prognostic factor for breast cancer on a large cohort of patients at a single institution.
  
  
  METHODS
  All 4,453 women diagnosed with breast cancer in Malmö University Hospital, Sweden between 1961 and 1991 were followed up on for 10 years with regards to breast cancer-specific mortality (BCSM) in different age groups. Corresponding relative risks (RR), with 95% confidence intervals, were obtained using Cox's proportional hazards analysis. All analyses were adjusted for potential confounders and stratified for axillary lymph node involvement (ALNI) and diagnostic period.
  
  
  RESULTS
  As compared to women aged 40 to 49 years, those who were aged under 40 (RR: 1.40; 95% CI: 1.04 to 1.88) and 80 or more years (RR: 1.80; 95% CI: 1.45 to 2.25) had a statistically significant higher 10-year mortality rate. When adjusted for potential confounders, including stage at diagnosis, the associations only remained statistically significant for women aged 80 years or more. In the analyses stratified on ALNI, ALNI-negative women under 40 years had a statistically significant higher five-year mortality rate (RR: 2.65; 95% CI: 1.23 to 5.70). In the analyses stratified on diagnostic period, the positive association between women aged under 40 or aged 80 or more years and high BCSM rate remained, with statistically significant results for women aged 80 years or more in all periods.
  
  
  CONCLUSIONS
  Women under 40 years of age had a poor prognosis, and this association was strongest among young women with axillary lymph node negative breast cancer. An age of 80 years or more was a prognostic factor for poor survival, independent of stage at diagnosis and diagnostic period.
authors.affiliation: Department of Surgery, Lund University, Skåne University Hospital Malmö, Inga Marie Nilssons gata 47, SE-205 02, Malmö, Sweden. jasmine.brandt@med.lu.se.|Department of Plastic Surgery, Lund University, Skåne University Hospital Malmö, Jan Waldenströmsgata 18, SE-205 02, Malmö, Sweden. jasmine.brandt@med.lu.se.
authors.forename: Jasmine
authors.initials: J
authors.lastname: Brandt
authors.affiliation: Department of Breast Surgery, Aalborg Hospital, Aarhus University Hospital, Skovvej 3, 9000, Aalborg, Denmark. jpg@rn.dk.
authors.forename: Jens Peter
authors.initials: JP
authors.lastname: Garne
authors.affiliation: Department of Surgery, Lund University, Skåne University Hospital Malmö, Inga Marie Nilssons gata 47, SE-205 02, Malmö, Sweden. ingrid.tengrup@skane.se.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Tengrup
authors.affiliation: Department of Surgery, Lund University, Skåne University Hospital Malmö, Inga Marie Nilssons gata 47, SE-205 02, Malmö, Sweden. jonas.manjer@med.lu.se.|Department of Plastic Surgery, Lund University, Skåne University Hospital Malmö, Jan Waldenströmsgata 18, SE-205 02, Malmö, Sweden. jonas.manjer@med.lu.se.
authors.forename: Jonas
authors.initials: J
authors.lastname: Manjer
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality* / Q000556:secondary; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000401:mortality* / Q000473:pathology; D018275:Carcinoma, Lobular / Q000401:mortality* / Q000556:secondary; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011379:Prognosis; D012307:Risk Factors; D015996:Survival Rate