title: Premorbid Obesity and Mortality in Patients With Pancreatic Cancer: A Systematic Review and Meta-analysis.
abstract: OBJECTIVE
  Obesity is associated with an increased risk for pancreatic cancer, but it is unclear whether it affects mortality. We performed a systematic review and meta-analysis to assess the association between premorbid obesity and mortality from pancreatic cancer.
  
  
  METHODS
  We performed a systematic search through January 2015 and identified studies of the association between premorbid obesity (at least 1 year prior to pancreatic cancer diagnosis) and pancreatic cancer-related mortality. We estimated summary adjusted hazard ratio (aHR) with 95% confidence interval (CI), comparing data from obese (body mass index [BMI] ≥30 kg/m(2)) and overweight subjects (BMI, 25.0-29.9 kg/m(2)) with those from individuals with a normal BMI (controls) by using random-effects model.
  
  
  RESULTS
  We identified 13 studies (including 3 studies that pooled multiple cohorts); 5 studies included only patients with pancreatic cancer, whereas 8 studies evaluated pancreatic cancer-related mortality in cancer-free individuals at inception. In the meta-analysis, we observed increase in pancreatic cancer-related mortality among overweight (aHR, 1.06; 95% CI, 1.02-1.11; I(2) = 0) and obese individuals (aHR, 1.31; 95% CI, 1.20-1.42; I(2) = 43%), compared with controls; the association remained when we analyzed data from only subjects with pancreatic cancer. Each 1 kg/m(2) increase in BMI was associated with 10% increase in mortality (aHR, 1.10; 95% CI, 1.05-1.15) with minimal heterogeneity (I(2) = 0). In the subgroup analysis, obesity was associated with increased mortality in Western populations (11 studies; aHR, 1.32; 95% CI, 1.22-1.42) but not in Asia-Pacific populations (2 studies; aHR, 0.98; 95% CI, 0.76-1.27).
  
  
  CONCLUSIONS
  In a systematic review and meta-analysis, we associated increasing level of obesity with increased mortality in patients with pancreatic cancer in Western but not Asia-Pacific populations. Strategies to reduce obesity-induced metabolic abnormalities might be developed to treat patients with pancreatic cancer.
authors.affiliation: Department of Surgery, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Kaustav
authors.initials: K
authors.lastname: Majumder
authors.affiliation: Department of Medicine, University of Texas Southwestern Medical Center, Dallas, Texas.
authors.forename: Arjun
authors.initials: A
authors.lastname: Gupta
authors.affiliation: Department of Surgery, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Nivedita
authors.initials: N
authors.lastname: Arora
authors.affiliation: Division of Medical Oncology, Washington University School of Medicine, St Louis, Missouri.
authors.forename: Preet Paul
authors.initials: PP
authors.lastname: Singh
authors.affiliation: Division of Gastroenterology, University of California, La Jolla, California. Electronic address: sis040@ucsd.edu.
authors.forename: Siddharth
authors.initials: S
authors.lastname: Singh
mesh_terms: D015992:Body Mass Index; D014943:Global Health; D006801:Humans; D009765:Obesity / Q000150:complications* / Q000453:epidemiology*; D010190:Pancreatic Neoplasms / Q000150:complications* / Q000401:mortality*
keywords: Adiposity; Malignancy; Pancreas; Survival