title: Changes in survival after breast cancer: improvements in diagnosis or treatment?
abstract: We have compared 5-year survival rates in two cohorts of women diagnosed with breast cancer in Brisbane, Australia, between 1981-1984 and 1990-1994. Tumours diagnosed in the early 1990s were significantly smaller and less likely to have nodal involvement than those diagnosed 10 years earlier (P<0.0001). The size difference was particularly striking for women aged over 50 at diagnosis, those targeted for screening. Five-year survival was greater among women diagnosed in the 1990s (84% vs. 74%; hazard ratio (HR) 0.61, 95% confidence interval (CI) 0.46-0.81). After adjusting for the effects of tumour size and nodal status this difference was reduced, but women diagnosed more recently still showed improved survival (HR 0.75; 95% CI 0.56-1.01) and disease-free survival (HR 0.72; 0.56-0.92) at 5 years. This suggests that both earlier diagnosis and changes in breast cancer treatment have contributed to improved breast cancer survival.
authors.affiliation: Queensland Institute of Medical Research, Royal Brisbane Hospital, Brisbane, Queensland, Australia. pennyW@qimr.edu.au
authors.forename: P M
authors.initials: PM
authors.lastname: Webb
authors.forename: M C
authors.initials: MC
authors.lastname: Cummings
authors.forename: C J
authors.initials: CJ
authors.lastname: Bain
authors.forename: C M
authors.initials: CM
authors.lastname: Furnival
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D015331:Cohort Studies; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008499:Medical Records; D008875:Middle Aged; D009367:Neoplasm Staging; D011793:Queensland / Q000453:epidemiology; D012189:Retrospective Studies; D016019:Survival Analysis