title: Weight Gain After Breast Cancer Diagnosis and All-Cause Mortality: Systematic Review and Meta-Analysis.
abstract: BACKGROUND
  Overweight and obesity are associated with breast cancer mortality. However, the relationship between postdiagnosis weight gain and mortality is unclear. We conducted a systematic review and meta-analysis of weight gain after breast cancer diagnosis and breast cancer-specific, all-cause mortality and recurrence outcomes.
  
  
  METHODS
  Electronic databases identified articles up through December 2014, including: PubMed (1966-present), EMBASE (1974-present), CINAHL (1982-present), and Web of Science. Language and publication status were unrestricted. Cohort studies and clinical trials measuring weight change after diagnosis and all-cause/breast cancer-specific mortality or recurrence were considered. Participants were women age 18 years or older with stage I-IIIC breast cancer. Fixed effects analysis summarized the association between weight gain (≥5.0% body weight) and all-cause mortality; all tests were two-sided.
  
  
  RESULTS
  Twelve studies (n = 23 832) were included. Weight gain (≥5.0%) compared with maintenance (<±5.0%) was associated with increased all-cause mortality (hazard ratio [HR] = 1.12, 95% confidence interval [CI] = 1.03 to 1.22, P = .01, I(2) = 55.0%). Higher risk of mortality was apparent for weight gain ≥10.0% (HR = 1.23, 95% CI = 1.09 to 1.39, P < .001); 5% to 10.0% weight gain was not associated with all-cause mortality (P = .40). The association was not statistically significant for those with a prediagnosis body mass index (BMI) of less than 25 kg/m(2) (HR = 1.14, 95% CI = 0.99 to 1.31, P = .07) or with a BMI of 25 kg/m(2) or higher (HR = 1.00, 95% CI = 0.86 to 1.16, P = .19). Weight gain of 10.0% or more was not associated with hazard of breast cancer-specific mortality (HR = 1.17, 95% CI = 1.00 to 1.38, P = .05).
  
  
  CONCLUSIONS
  Weight gain after diagnosis of breast cancer is associated with higher all-cause mortality rates compared with maintaining body weight. Adverse effects are greater for weight gains of 10.0% or higher.
authors.affiliation: Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale University, New Haven, CT (MCP, MLI, MBB, MH); Yale Cancer Center, New Haven, CT (MLI, TBS); Dana-Farber Cancer Institute, Boston, MA (JAL). mary.playdon@yale.edu.
authors.forename: Mary C
authors.initials: MC
authors.lastname: Playdon
authors.affiliation: Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale University, New Haven, CT (MCP, MLI, MBB, MH); Yale Cancer Center, New Haven, CT (MLI, TBS); Dana-Farber Cancer Institute, Boston, MA (JAL).
authors.forename: Michael B
authors.initials: MB
authors.lastname: Bracken
authors.affiliation: Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale University, New Haven, CT (MCP, MLI, MBB, MH); Yale Cancer Center, New Haven, CT (MLI, TBS); Dana-Farber Cancer Institute, Boston, MA (JAL).
authors.forename: Tara B
authors.initials: TB
authors.lastname: Sanft
authors.affiliation: Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale University, New Haven, CT (MCP, MLI, MBB, MH); Yale Cancer Center, New Haven, CT (MLI, TBS); Dana-Farber Cancer Institute, Boston, MA (JAL).
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Ligibel
authors.affiliation: Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale University, New Haven, CT (MCP, MLI, MBB, MH); Yale Cancer Center, New Haven, CT (MLI, TBS); Dana-Farber Cancer Institute, Boston, MA (JAL).
authors.forename: Maura
authors.initials: M
authors.lastname: Harrigan
authors.affiliation: Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale University, New Haven, CT (MCP, MLI, MBB, MH); Yale Cancer Center, New Haven, CT (MLI, TBS); Dana-Farber Cancer Institute, Boston, MA (JAL).
authors.forename: Melinda L
authors.initials: ML
authors.lastname: Irwin
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000401:mortality* / Q000473:pathology; D002423:Cause of Death; D005260:Female; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D009765:Obesity / Q000150:complications / Q000401:mortality; D016017:Odds Ratio; D050177:Overweight / Q000150:complications / Q000401:mortality; D011379:Prognosis; D012307:Risk Factors; D015430:Weight Gain