title: Association between body mass index and risk of formation of breast cancer in Chinese women.
abstract: OBJECTIVE
  To analyse the association between body mass index (BMI) and breast cancer risk among Chinese women in Hong Kong.
  
  
  METHODS
  We conducted a population-based case control study of breast cancer in June 2002. Standardized questionnaires concerning BMI and other anthropometric data were completed by patients at the Queen Mary Hospital (QMH). The cases were 198 women aged 24-85 years who had documented breast cancer in 1995-2000 by triple assessment criteria, and the controls were 353 women who were followed up at QMH for benign breast disease after breast cancer had been excluded by triple assessment. The controls were frequency-matched to the cases by age.
  
  
  RESULTS
  BMI at diagnosis was positively correlated with the risk of breast cancer among postmenopausal women (p < 0.001 for trend). Also, when compared with women with a low BMI (< 19), women with a BMI of 23-27 and 27-31 had a 1.73-fold (95% confidence interval, CI, 1.04-2.86) and 2.06-fold (95% CI, 1.08-3.93) increased risk of breast cancer, respectively, after adjustment for non-anthropometric risk factors. BMI at diagnosis, however, was not related to the risk of breast cancer among premenopausal women. The odds ratios for premenopausal women with a BMI of 23-27 and 27-31 were 1.5 (95% CI, 0.82-2.71) and 1.32 (95% CI, 0.39-4.43), respectively. Furthermore, present BMI and BMI 5 years before diagnosis were poorly associated with breast cancer risk among both pre- and postmenopausal women.
  
  
  CONCLUSIONS
  Weight control in obese women may be an effective measure for breast cancer prevention in postmenopausal women.
authors: Department of Surgery, University of Hong Kong, Hong Kong SAR, China. lwcchow@hkucc.hku.hk
authors: Louis W C
authors: LW
authors: Chow
authors: Ka Luen
authors: KL
authors: Lui
authors: Johnny Chun Yin
authors: JC
authors: Chan
authors: Tuen Ching
authors: TC
authors: Chan
authors: Po Ki
authors: PK
authors: Ho
authors: Wing Yi
authors: WY
authors: Lee
authors: Lik Hang
authors: LH
authors: Leung
authors: Wing Man
authors: WM
authors: Sy
authors: Chin Chin
authors: CC
authors: Yeung
authors: Amy Ka Man
authors: AK
authors: Yung
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000175:diagnosis / Q000453:epidemiology*; D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D015897:Comorbidity; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D009765:Obesity / Q000175:diagnosis / Q000453:epidemiology*; D016017:Odds Ratio; D017698:Postmenopause; D017697:Premenopause; D011336:Probability; D012016:Reference Values; D018570:Risk Assessment; D015996:Survival Rate