title: Stage at diagnosis and ovarian cancer survival: evidence from the International Cancer Benchmarking Partnership.
abstract: OBJECTIVE
  We investigate what role stage at diagnosis bears in international differences in ovarian cancer survival.
  
  
  METHODS
  Data from population-based cancer registries in Australia, Canada, Denmark, Norway, and the UK were analysed for 20,073 women diagnosed with ovarian cancer during 2004-07. We compare the stage distribution between countries and estimate stage-specific one-year net survival and the excess hazard up to 18 months after diagnosis, using flexible parametric models on the log cumulative excess hazard scale.
  
  
  RESULTS
  One-year survival was 69% in the UK, 72% in Denmark and 74-75% elsewhere. In Denmark, 74% of patients were diagnosed with FIGO stages III-IV disease, compared to 60-70% elsewhere. International differences in survival were evident at each stage of disease; women in the UK had lower survival than in the other four countries for patients with FIGO stages III-IV disease (61.4% vs. 65.8-74.4%). International differences were widest for older women and for those with advanced stage or with no stage data.
  
  
  CONCLUSIONS
  Differences in stage at diagnosis partly explain international variation in ovarian cancer survival, and a more adverse stage distribution contributes to comparatively low survival in Denmark. This could arise because of differences in tumour biology, staging procedures or diagnostic delay. Differences in survival also exist within each stage, as illustrated by lower survival for advanced disease in the UK, suggesting unequal access to optimal treatment. Population-based data on cancer survival by stage are vital for cancer surveillance, and global consensus is needed to make stage data in cancer registries more consistent.
authors: Cancer Research UK Cancer Survival Group, Department of Non Communicable Disease Epidemiology, London School of Hygiene and Tropical Medicine, and St. Bartholomew's Hospital, London, UK. Camille.Maringe@lshtm.ac.uk
authors: Camille
authors: C
authors: Maringe
authors: Sarah
authors: S
authors: Walters
authors: John
authors: J
authors: Butler
authors: Michel P
authors: MP
authors: Coleman
authors: Neville
authors: N
authors: Hacker
authors: Louise
authors: L
authors: Hanna
authors: Berit J
authors: BJ
authors: Mosgaard
authors: Andy
authors: A
authors: Nordin
authors: Barry
authors: B
authors: Rosen
authors: Gerda
authors: G
authors: Engholm
authors: Marianne L
authors: ML
authors: Gjerstorff
authors: Juanita
authors: J
authors: Hatcher
authors: Tom B
authors: TB
authors: Johannesen
authors: Colleen E
authors: CE
authors: McGahan
authors: David
authors: D
authors: Meechan
authors: Richard
authors: R
authors: Middleton
authors: Elizabeth
authors: E
authors: Tracey
authors: Donna
authors: D
authors: Turner
authors: Michael A
authors: MA
authors: Richards
authors: Bernard
authors: B
authors: Rachet
mesh_terms: D000368:Aged; D001315:Australia / Q000453:epidemiology; D002170:Canada / Q000453:epidemiology; D005260:Female; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D009664:Norway / Q000453:epidemiology; D010051:Ovarian Neoplasms / Q000175:diagnosis / Q000401:mortality* / Q000473:pathology*; D016019:Survival Analysis; D006113:United Kingdom / Q000453:epidemiology