title: No inequalities in survival from colorectal cancer by education and socioeconomic deprivation - a population-based study in the North Region of Portugal, 2000-2002.
abstract: Association between cancer survival and socioeconomic status has been reported in various countries but it has never been studied in Portugal. We aimed here to study the role of education and socioeconomic deprivation level on survival from colorectal cancer in the North Region of Portugal using a population-based cancer registry dataset.
  
  
  
  We analysed a cohort of patients aged 15-84 years, diagnosed with a colorectal cancer in the North Region of Portugal between 2000 and 2002. Education and socioeconomic deprivation level was assigned to each patient based on their area of residence. We measured socioeconomic deprivation using the recently developed European Deprivation Index. Net survival was estimated using Pohar-Perme estimator and age-adjusted excess hazard ratios were estimated using parametric flexible models. Since no deprivation-specific life tables were available, we performed a sensitivity analysis to test the robustness of the results to life tables adjusted for education and socioeconomic deprivation level.
  
  
  
  A total of 4,105 cases were included in the analysis. In male patients (56.3 %), a pattern of worse 5- and 10-year net survival in the less educated (survival gap between extreme education groups: -7 % and -10 % at 5 and 10 years, respectively) and more deprived groups (survival gap between extreme EDI groups: -5 % both at 5 and 10 years) was observed when using general life tables. No such clear pattern was found among female patients. In both sexes, when likely differences in background mortality by education or deprivation were accounted for in the sensitivity analysis, any differences in net survival between education or deprivation groups vanished.
  
  
  
  Our study shows that observed differences in survival by education and EDI level are most likely attributable to inequalities in background survival. Also, it confirms the importance of using the relevant life tables and of performing sensitivity analysis when evaluating socioeconomic inequalities in cancer survival. Comparison studies of different healthcare systems organization should be performed to better understand its influence on cancer survival inequalities.
authors: Department of Epidemiology, Portuguese Oncology Institute (IPO Porto), Porto, Portugal.|RORENO - North Region Cancer Registry of Portugal, Porto, Portugal.|Faculty of Sciences, University of Porto, Porto, Portugal.
authors: Luís
authors: L
authors: Antunes
authors: EPIUnit - Institute of Public Health - University of Porto (ISPUP), Porto, Portugal.|Institute of Biomedical Sciences Abel Salazar, University of Porto, Porto, Portugal.
authors: Denisa
authors: D
authors: Mendonça
authors: Department of Epidemiology, Portuguese Oncology Institute (IPO Porto), Porto, Portugal.|RORENO - North Region Cancer Registry of Portugal, Porto, Portugal.|UMIB, Institute of Biomedical Sciences Abel Salazar, University of Porto, Porto, Portugal.
authors: Maria José
authors: MJ
authors: Bento
authors: Cancer Survival Group, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK. bernard.rachet@lshtm.ac.uk.
authors: Bernard
authors: 0000-0001-5837-7773
authors: B
authors: Rachet
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000401:mortality*; D004522:Educational Status; D005260:Female; D054625:Healthcare Disparities / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011174:Portugal / Q000453:epidemiology; D012923:Social Class; D012959:Socioeconomic Factors; D055815:Young Adult
keywords: Colorectal cancer; Deprivation; Education; Inequalities; Life tables; Net survival