title: [Effect of body mass index on disease-free and overall survival in Chinese women with breast cancer].
abstract: OBJECTIVE
  Obesity has been shown to be an indicator of poor prognosis for patients with primary breast cancer. The aim of this study was to clarify the effect of obesity on Chinese women with breast cancer.
  
  
  METHODS
  This is a retrospective analysis of 1699 breast cancer patients. We evaluated the effect of body mass index (BMI) on disease-free survival (DFS) and overall survival (OS) in these patients. BMI was obtained before surgery. Obesity was defined as a BMI ≥ 24. Kaplan-Meier analysis and Log rank test were employed to perform survival analysis. The impact of different characteristics on survival was assessed by using Cox proportional-hazards regression model.
  
  
  RESULTS
  In total 635 (37.4%) patients were obese, while 1 064 (62.6%) were non-obese. Comparing the tumor characteristics in the two groups, the BMI ≥ 24 group showed a higher rate of older age (P < 0.001), postmenopausal status (P < 0.001), increased risk of lymph node metastasis (P = 0.001) and less chances of accepting breast conservation surgery (P = 0.012). The median follow-up time was 16 months, and the estimated 16-months DFS was 98.1% for non-obese and 95.0% for obese patients (P = 0.007), the estimated 16-months OS was 99.4% for non-obese and 98.4% for obese patients (P = 0.004). The multivariate analysis indicated that obesity is an independent prognostic factor for OS and DFS in breast cancer patients.
  
  
  CONCLUSIONS
  Our findings suggest that obesity is associated with a poorer outcome in Chinese female patients with breast cancer.
authors.affiliation: Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Comprehensive Breast Health Center, Shanghai 200025, China.
authors.forename: Yuzi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Comprehensive Breast Health Center, Shanghai 200025, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Qu
authors.affiliation: Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Comprehensive Breast Health Center, Shanghai 200025, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Mao
authors.affiliation: Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Comprehensive Breast Health Center, Shanghai 200025, China; Email: kwshen@medmail.com.cn.
authors.forename: Kunwei
authors.initials: K
authors.lastname: Shen
mesh_terms: D015992:Body Mass Index; D001943:Breast Neoplasms / Q000453:epidemiology*; D002681:China / Q000453:epidemiology; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D009765:Obesity; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D016019:Survival Analysis