Changes in lung cancer survival by TNM stage in the Basque country from 2003 to 2014 according to period of diagnosis

Abstract Introduction The objective of this study was to analyze the survival of patients with lung cancer by TNM stage in the 4-year periods 2003–2006, 2007–2010 and 2011–2014, treated in the Basque Health Service, and to compare this with survival in an equivalent sample of the general population. Methods A retrospective observational design was applied to cases from the Hospital Cancer Registry of Euskadi. A cohort of 11,635 patients had complete data for the following variables: TNM stage, age, sex, histology, date of diagnosis, vital status and date of death. Relative survival and Cox and parametric regression models were used to assess changes in survival. Results The lung cancer 5-year survival probability decreased with increasing stage, from 50–65% in patients with stage I disease to 2–3% in those with stage IV disease. Comparing patients diagnosed from 2011–2014 and 2003–2006, we found that survival improved: (a) the risk of death (hazard ratio) in 2003–2006 was 1.66 for stage I, 1.51 for stage II, 1.21 for stage III, and 1.10 for stage IV; (b) the 5-year relative survival increased from 11.0% to 17.8% in the period 2011–2014; and (c) the years of life lost decreased significantly from 2003–2006 to 2011–2014, varying between 6.16 (stage I) and 16.21 (stage IV). Conclusions Survival from lung cancer by stage in the Basque Country has lengthened significantly across all disease stages. Nonetheless, since we estimated that lung cancer patients still have significantly lower mean survival times than the general population, there is a need for more research to improve these outcomes.