title: Association between body mass index and mortality for colorectal cancer survivors: overall and by tumor molecular phenotype.
abstract: BACKGROUND
  Microsatellite instability (MSI) and BRAF mutation status are associated with colorectal cancer survival, whereas the role of body mass index (BMI) is less clear. We evaluated the association between BMI and colorectal cancer survival, overall and by strata of MSI, BRAF mutation, sex, and other factors.
  
  
  METHODS
  This study included 5,615 men and women diagnosed with invasive colorectal cancer who were followed for mortality (maximum: 14.7 years; mean: 5.9 years). Prediagnosis BMI was derived from self-reported weight approximately one year before diagnosis and height. Tumor MSI and BRAF mutation status were available for 4,131 and 4,414 persons, respectively. Multivariable hazard ratios (HR) and 95% confidence intervals (CI) were estimated from delayed-entry Cox proportional hazards models.
  
  
  RESULTS
  In multivariable models, high prediagnosis BMI was associated with higher risk of all-cause mortality in both sexes (per 5-kg/m(2); HR, 1.10; 95% CI, 1.06-1.15), with similar associations stratified by sex (Pinteraction: 0.41), colon versus rectum (Pinteraction: 0.86), MSI status (Pinteraction: 0.84), and BRAF mutation status (Pinteraction: 0.28). In joint models, with MS-stable/MSI-low and normal BMI as the reference group, risk of death was higher for MS-stable/MSI-low and obese BMI (HR, 1.32; P value: 0.0002), not statistically significantly lower for MSI-high and normal BMI (HR, 0.86; P value: 0.29), and approximately the same for MSI-high and obese BMI (HR, 1.00; P value: 0.98).
  
  
  CONCLUSIONS
  High prediagnosis BMI was associated with increased mortality; this association was consistent across participant subgroups, including strata of tumor molecular phenotype.
  
  
  CONCLUSIONS
  High BMI may attenuate the survival benefit otherwise observed with MSI-high tumors.
authors.affiliation: Epidemiology Research Program, American Cancer Society, Atlanta, Georgia. peter.campbell@cancer.org.
authors.forename: Peter T
authors.initials: PT
authors.lastname: Campbell
authors.affiliation: Epidemiology Research Program, American Cancer Society, Atlanta, Georgia.
authors.forename: Christina C
authors.initials: CC
authors.lastname: Newton
authors.affiliation: Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington.
authors.forename: Polly A
authors.initials: PA
authors.lastname: Newcomb
authors.affiliation: Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington.
authors.forename: Amanda I
authors.initials: AI
authors.lastname: Phipps
authors.affiliation: Department of Veterans Affairs, Eastern Colorado Health Care System, University of Colorado School of Medicine, Aurora, Colorado.
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Ahnen
authors.affiliation: University of North Carolina School of Medicine, Chapel Hill, North Carolina.
authors.forename: John A
authors.initials: JA
authors.lastname: Baron
authors.affiliation: Centre for Epidemiology and Biostatistics, University of Melbourne, Melbourne, Australia.
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Buchanan
authors.affiliation: Department of Preventive Medicine, Keck School of Medicine, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California.
authors.forename: Graham
authors.initials: G
authors.lastname: Casey
authors.affiliation: University Health Network, Department of Surgery, Toronto, Ontario, Canada.
authors.forename: Sean P
authors.initials: SP
authors.lastname: Cleary
authors.affiliation: Prevention and Cancer Control, Cancer Care Ontario, Toronto, Ontario, Canada.
authors.forename: Michelle
authors.initials: M
authors.lastname: Cotterchio
authors.affiliation: Department of Pathology, Emory University, Atlanta, Georgia.
authors.forename: Alton B
authors.initials: AB
authors.lastname: Farris
authors.affiliation: Department of Preventive Medicine, Keck School of Medicine, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California.
authors.forename: Jane C
authors.initials: JC
authors.lastname: Figueiredo
authors.affiliation: Lunenfeld-Tanenbaum Research Institute, Toronto, Ontario, Canada.
authors.forename: Steven
authors.initials: S
authors.lastname: Gallinger
authors.affiliation: Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada.
authors.forename: Roger C
authors.initials: RC
authors.lastname: Green
authors.affiliation: Stanford University, Palo Alto, California.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Haile
authors.affiliation: Centre for Epidemiology and Biostatistics, University of Melbourne, Melbourne, Australia.
authors.forename: John L
authors.initials: JL
authors.lastname: Hopper
authors.affiliation: Centre for Epidemiology and Biostatistics, University of Melbourne, Melbourne, Australia.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Jenkins
authors.affiliation: University of Hawaii Cancer Center, Honolulu, Hawaii.
authors.forename: Loïc
authors.initials: L
authors.lastname: Le Marchand
authors.affiliation: Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington.
authors.forename: Karen W
authors.initials: KW
authors.lastname: Makar
authors.affiliation: Prosserman Centre for Health Research, Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: John R
authors.initials: JR
authors.lastname: McLaughlin
authors.affiliation: Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington.
authors.forename: John D
authors.initials: JD
authors.lastname: Potter
authors.affiliation: Institute of Cancer Sciences, University of Manchester, Manchester, United Kingdom.
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Renehan
authors.affiliation: Department of Medicine and Oncology, GI Research Unit, Mayo Clinic Cancer Center, Rochester, Minnesota.
authors.forename: Frank A
authors.initials: FA
authors.lastname: Sinicrope
authors.affiliation: Department of Lab Medicine and Pathology, Mayo Clinic Cancer Center, Rochester, Minnesota.
authors.forename: Stephen N
authors.initials: SN
authors.lastname: Thibodeau
authors.affiliation: Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington. Population Sciences, Huntsman Cancer Institute, Salt Lake City, Utah.
authors.forename: Cornelia M
authors.initials: CM
authors.lastname: Ulrich
authors.affiliation: Centre for Epidemiology and Biostatistics, University of Melbourne, Melbourne, Australia.
authors.forename: Aung Ko
authors.initials: AK
authors.lastname: Win
authors.affiliation: Department of Health Sciences Research, Mayo Clinic, Scottsdale, Arizona.
authors.forename: Noralane M
authors.initials: NM
authors.lastname: Lindor
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic Cancer Center, Rochester, Minnesota.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Limburg
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality; D005260:Female; D006801:Humans; D008297:Male; D053842:Microsatellite Instability; D008875:Middle Aged; D010641:Phenotype; D011446:Prospective Studies; D016019:Survival Analysis; D017741:Survivors; D055815:Young Adult