title: Obtaining tissue diagnosis in lung cancer patients with poor performance status and its influence on treatment and survival.
abstract: 25% of patients with lung cancer have performance status 3 or 4. A pragmatic approach to investigative procedures is often adopted based on the risks and benefits in these patients and whether tissue diagnosis is necessary for anticipated future treatment. This cohort study investigated factors influencing a clinician's decision to pursue a tissue diagnosis in patients with lung cancer and performance status 3 and 4 and to examine the association of tissue diagnosis with subsequent management and survival.
  
  
  
  All patients with lung cancer diagnosed in North Glasgow from 2009 to 2012 were prospectively recorded in a registry. We investigated the relationships between achieving a tissue diagnosis, treatment and survival.
  
  
  
  Of 2493 patients diagnosed with lung cancer, 490 patients (20%) were PS 3 and 122 patients (5%) were PS 4. Tissue diagnosis was attempted in 60% and 35% patients with PS 3 and PS 4 respectively. Younger age, better performance status and having stage 4 disease were independently associated with a diagnostic procedure being performed. Only 5% of patients with poor performance status received treatment conventionally requiring a tissue diagnosis. Age, stage and performance status were independent predictors of mortality. Achieving a tissue diagnosis was not associated with mortality. Receiving treatment requiring tissue diagnosis is associated with survival benefit.
  
  
  
  The majority of patients with poor fitness undergo a diagnostic procedure which does not influence further treatment or affect survival. However, the cohort of patients who do undergo therapy determined by tissue diagnosis have improved survival.
authors.affiliation: Department of Respiratory Medicine, Glasgow Royal Infirmary, Glasgow, UK.
authors.forename: John D
authors.initials: JD
authors.lastname: Maclay
authors.affiliation: Department of Respiratory Medicine, Stobhill Hospital/Glasgow Royal Infirmary, Glasgow, UK. Electronic address: johnfarley@nhs.net.
authors.forename: John M B
authors.initials: JM
authors.lastname: Farley
authors.affiliation: Health Informatics Department, Glasgow University, Glasgow, UK.
authors.forename: Colin
authors.initials: C
authors.lastname: McCowan
authors.affiliation: Department of Respiratory Medicine, Stobhill Hospital/Glasgow Royal Infirmary, Glasgow, UK.
authors.forename: Conor
authors.initials: C
authors.lastname: Tweed
authors.affiliation: Department of Respiratory Medicine, Stobhill Hospital/Glasgow Royal Infirmary, Glasgow, UK.
authors.forename: Robert
authors.initials: R
authors.lastname: Milroy
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D003657:Decision Making; D005260:Female; D006650:Histocompatibility Testing / Q000592:standards*; D006653:Histology / Q000592:standards*; D006801:Humans; D017567:Karnofsky Performance Status; D008175:Lung Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009026:Mortality / Q000639:trends; D009367:Neoplasm Staging; D011446:Prospective Studies; D016019:Survival Analysis
keywords: Histology; Lung cancer; Mortality; Performance status