title: Comorbidity in Patients With Small-Cell Lung Cancer: Trends and Prognostic Impact.
abstract: BACKGROUND
  We evaluated the trends in the prevalence of comorbidity and its prognostic impact in a cohort of unselected patients with small-cell lung cancer (SCLC).
  
  
  METHODS
  All patients (n = 4142) diagnosed with SCLC from 1995 to 2012 were identified from the population-based Netherlands Cancer Registry in the Eindhoven region.
  
  
  RESULTS
  The prevalence of comorbidity increased from 55% in 1995 to 1998 to 76% in 2011 to 2012 and multimorbidity (ie, ≥ 2 concomitant diseases) from 23% to 51%. The prevalence of a comorbidity increased with age. Among the men, hypertension, cardiac disease, and diabetes, in particular, became more common (increased from 11% to 35%, from 19% to 36%, and from 7% to 18%, respectively). In the women, the rate of pulmonary disease, hypertension, and cardiac disease increased the most (increased from 18% to 30%, from 12% to 28%, and from 11% to 24%, respectively). Multimorbidity was associated with a slightly increased hazard of death, independent of treatment in those with limited-stage SCLC (hazard ratio [HR] for ≥ 2 comorbidities vs. no comorbidities, 1.2; 95% confidence interval [CI], 1.0-1.4). The prognostic effects of multimorbidity resulted from treatment in those with extensive-stage SCLC (HR for ≥ 2 comorbidities vs. no comorbidities, final model, 1.2; 95% CI, 1.0-1.2). The prognostic impact of the specific comorbidities varied, with digestive disease reducing the hazard and cardiac disease increasing the hazard in those with limited-stage SCLC (HR for digestive disease vs. no digestive disease, 0.7 [95% CI, 0.5-0.9], and HR for cardiac vs. no cardiac disease, 1.2 [95% CI, 1.0-1.3]). Also, cardiac and cerebrovascular disease increased the hazard in those with extensive-stage SCLC (HR 1.2 [95% CI, 1.0-1.3] and HR 1.3 [95% CI, 1.1-1.6], respectively).
  
  
  CONCLUSIONS
  Comorbidity among patients with SCLC is very common and has been increasing. Multimorbidity was associated with a slightly increased hazard of death in those with limited-stage SCLC, independent of treatment. However, the prognostic effects in those with advanced-stage SCLC resulted from treatment. Digestive disease favorably affected survival and cardiac disease negatively affected the prognosis for those with limited-stage SCLC, and cardiac and cerebrovascular diseases had a negative prognostic effect for those with extensive-stage SCLC. With the burden of comorbidities in patients with SCLC increasing, more attention to individualized treatment approaches is needed.
authors.affiliation: Netherlands Cancer Registry, Netherlands Comprehensive Cancer Organisation (IKNL), Eindhoven, The Netherlands. Electronic address: m.aarts@iknl.nl.
authors.forename: Mieke J
authors.initials: MJ
authors.lastname: Aarts
authors.affiliation: Department of Pulmonary Diseases, Amphia Hospital, Breda, The Netherlands; Department of Pulmonary Diseases, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: Joachim G
authors.initials: JG
authors.lastname: Aerts
authors.affiliation: Department of Pulmonary Diseases, Catharina Hospital, Eindhoven, The Netherlands.
authors.forename: Ben E
authors.initials: BE
authors.lastname: van den Borne
authors.affiliation: Department of Pulmonary Diseases, Jeroen Bosch Hospital, 's-Hertogenbosch, The Netherlands.
authors.forename: Bonne
authors.initials: B
authors.lastname: Biesma
authors.affiliation: Netherlands Cancer Registry, Netherlands Comprehensive Cancer Organisation (IKNL), Eindhoven, The Netherlands; Department of Public Health, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: Valery E P P
authors.initials: VE
authors.lastname: Lemmens
authors.affiliation: Department of Pulmonary Diseases, TweeSteden Hospital and St. Elisabeth Hospital, Tilburg, The Netherlands.
authors.forename: Jeroen S
authors.initials: JS
authors.lastname: Kloover
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D005260:Female; D006801:Humans; D007223:Infant; D008175:Lung Neoplasms / Q000453:epidemiology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D015995:Prevalence; D011379:Prognosis; D016016:Proportional Hazards Models; D012042:Registries; D055752:Small Cell Lung Carcinoma / Q000453:epidemiology* / Q000473:pathology; D015996:Survival Rate; D055815:Young Adult
keywords: Cancer registry; Population-based; Survival