title: Premorbid body mass index and mortality in patients with lung cancer: A systematic review and meta-analysis.
abstract: We aimed to assess the association between premorbid obesity, measured using body mass index (BMI) and lung cancer-related mortality, through a systematic review and meta-analysis.
  
  
  
  Observational studies reporting statistical measures of association between premorbid BMI categories and lung cancer-related mortality were included in our study. We estimated hazard ratios (aHR) with 95% confidence intervals (CI), comparing lung cancer-related mortality across BMI categories. The main outcome measure was lung cancer-related mortality in obese (BMI≥30kg/m2) and overweight participants (BMI 25.0-29.9kg/m2), compared with normal BMI participants.
  
  
  
  We included 14 studies (including 2 pooled cohort studies) comprising 3,008,137 cancer-free participants at inception, reporting 28,592 lung cancer-related deaths. On meta-analysis, we observed a significantly lower lung cancer-related mortality in overweight (aHR, 0.76; 95% CI, 0.68-0.85) and obese (aHR, 0.68, 95% CI; 0.57-0.81) participants as compared to participants with normal BMI, with considerable heterogeneity; after excluding one study with large effect size, a more conservative and consistent association was observed between BMI and lung cancer-related mortality (overweight vs. normal BMI: aHR, 0.84; 95% CI, 0.79-0.90; obese vs. normal BMI: aHR, 0.81; 95% CI, 0.75-0.87), with moderate heterogeneity. Were similar in men vs. women, non-smokers vs. smokers, and Western vs Asia-Pacific populations.
  
  
  
  Based on meta-analysis, we observed an independent protective association between premorbid obesity and lung cancer-related mortality. This association was observed across sex, smoking status and geographic region. Further studies are needed to prospectively study this association.
authors.affiliation: Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States.
authors.forename: Arjun
authors.initials: A
authors.lastname: Gupta
authors.affiliation: Department of Surgical Sciences, University of Minnesota, Minneapolis, MN, United States.
authors.forename: Kaustav
authors.initials: K
authors.lastname: Majumder
authors.affiliation: Department of Surgical Sciences, University of Minnesota, Minneapolis, MN, United States.
authors.forename: Nivedita
authors.initials: N
authors.lastname: Arora
authors.affiliation: University of Texas Southwestern Medical Center Library, Dallas, TX, United States.
authors.forename: Helen G
authors.initials: HG
authors.lastname: Mayo
authors.affiliation: Department of Medical Oncology, Washington University School of Medicine, St. Louis, MO, United States.
authors.forename: Preet Paul
authors.initials: PP
authors.lastname: Singh
authors.affiliation: Division of Hematology Oncology, University of Texas Southwestern Medical Center, Dallas, TX, United States.
authors.forename: Muhammad S
authors.initials: MS
authors.lastname: Beg
authors.affiliation: Division of Hematology Oncology, University of Texas Southwestern Medical Center, Dallas, TX, United States.
authors.forename: Randall
authors.initials: R
authors.lastname: Hughes
authors.affiliation: Division of Gastroenterology, University of California San Diego, La Jolla, CA, United States.
authors.forename: Siddharth
authors.initials: S
authors.lastname: Singh
authors.affiliation: Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States. Electronic address: david.johnson@utsouthwestern.edu.
authors.forename: David H
authors.initials: DH
authors.lastname: Johnson
mesh_terms: D000328:Adult; D000368:Aged; D001208:Asia / Q000453:epidemiology; D015992:Body Mass Index; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000453:epidemiology / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000453:epidemiology / Q000401:mortality*; D064887:Observational Studies as Topic; D050177:Overweight / Q000453:epidemiology / Q000401:mortality*; D011379:Prognosis
keywords: Body mass index; Lung cancer; Mortality; Obesity; Overweight; Premorbid; Prognosis