title: Improvements in breast cancer survival between 1995 and 2012 in Denmark: The importance of earlier diagnosis and adjuvant treatment.
abstract: Background Breast cancer mortality has declined from 1995 through 2012 which may be attributed to earlier diagnosis, changes in lifestyle risk factors, and improved treatments. To a large extent the relative contribution of these modalities are unknown. Mammography screening was introduced late in Denmark; in 1995 around 20% of the Danish female population aged 50-69 was covered by population-based screening, and this was in 2008 extended to the entire population. Breast conserving surgery gradually replaced mastectomy, and sentinel node biopsy was introduced. In the same period adjuvant treatment was extended considerable. Methods A population-based study of 68 842 breast cancer patients registered in the clinical database of the Danish Breast Cancer Cooperative Group in 1995-2012. Comprehensive data on prognostic factors, comorbidity and treatment together with complete follow-up for survival were used to evaluate improvements in mortality and standardized mortality rate in successive time periods. Results The results from this study demonstrated a significant improvement in prognosis in successive time periods covering 1995-2012. Apart from patients with a high Charlson Comorbidity Index (CCI) improvements were seen in all subgroups of patients. Prognostic factors were more favorable in the latest time period accordingly to the introduction of nationwide screening. In the study period adjuvant treatment was extended considerable. Conclusion The impact of screening was by nature of limited magnitude. The modified treatment strategies implemented by the use of nationwide guidelines seemed to have a major impact on the substantial survival improvements.
authors.affiliation: a Danish Breast Cancer Cooperative Group (DBCG) Secretariat and Statistical Office, Rigshospitalet, Copenhagen University Hospital , Copenhagen , Denmark ;
authors.forename: Maj-Britt
authors.initials: MB
authors.lastname: Jensen
authors.affiliation: a Danish Breast Cancer Cooperative Group (DBCG) Secretariat and Statistical Office, Rigshospitalet, Copenhagen University Hospital , Copenhagen , Denmark ;
authors.forename: Bent
authors.initials: B
authors.lastname: Ejlertsen
authors.affiliation: a Danish Breast Cancer Cooperative Group (DBCG) Secretariat and Statistical Office, Rigshospitalet, Copenhagen University Hospital , Copenhagen , Denmark ;
authors.forename: Henning T
authors.initials: HT
authors.lastname: Mouridsen
authors.affiliation: b Department of Surgery , Breast Surgery Unit, Aarhus University Hospital/Randers Regional Hospital , Aarhus , Denmark.
authors.forename: Peer
authors.initials: P
authors.lastname: Christiansen
mesh_terms: D000276:Adjuvants, Immunologic / Q000627:therapeutic use; D000293:Adolescent; D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000401:mortality* / Q000628:therapy; D015897:Comorbidity; D003718:Denmark / Q000453:epidemiology; D055088:Early Detection of Cancer; D005260:Female; D006801:Humans; D008327:Mammography; D008403:Mass Screening; D015412:Mastectomy, Segmental; D008875:Middle Aged; D011379:Prognosis; D015996:Survival Rate; D055815:Young Adult
chemical_list: D000276:Adjuvants, Immunologic