title: Overweight, obesity and risk of premenopausal breast cancer according to ethnicity: a systematic review and dose-response meta-analysis.
abstract: The association of overweight and obesity with premenopausal breast cancer remained unclear, ethnicity could play a role. A MEDLINE and PUBMED search of all studies on obesity and premenopausal breast cancer published from 2000 to 2010 was conducted. Dose-response meta-analysis was used to determine the risk of premenopausal breast cancer associated with different anthropometric measurements in different ethnic groups. For body mass index (BMI), each 5 kg m(-2) increase was inversely associated with the risk of premenopausal breast cancer (RR = 0.95, 95% confidence interval [CI]: 0.94, 0.97). After stratification by ethnicity, the inverse association remained significant only among Africans (RR = 0.95, 95% CI: 0.91, 0.98) and Caucasians (RR = 0.93, 95% CI: 0.91, 0.95). In contrast, among Asian women, a significant positive association was observed. For waist-to-hip ratio (WHR), each 0.1 unit increase was positively associated with premenopausal breast cancer (RR = 1.08, 95% CI: 1.01, 1.16); the largest effect was detected in Asian women (RR = 1.19, 95% CI: 1.15, 1.24), while small effects of 5% and 6% were observed in African and Caucasian women, respectively. Our results suggest the importance of considering both fat distribution and ethnicity when studying premenopausal breast cancer.
authors.affiliation: Nutrition and Metabolism Section/Nutritional Epidemiology Group, International Agency for Research on Cancer, Lyon, France.
authors.forename: A
authors.initials: A
authors.lastname: Amadou
authors.forename: P
authors.initials: P
authors.lastname: Ferrari
authors.forename: R
authors.initials: R
authors.lastname: Muwonge
authors.forename: A
authors.initials: A
authors.lastname: Moskal
authors.forename: C
authors.initials: C
authors.lastname: Biessy
authors.forename: I
authors.initials: I
authors.lastname: Romieu
authors.forename: P
authors.initials: P
authors.lastname: Hainaut
mesh_terms: D000328:Adult; D044466:Asian People / Q000706:statistics & numerical data; D044383:Black People / Q000706:statistics & numerical data; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000208:ethnology*; D005260:Female; D006801:Humans; D009765:Obesity / Q000150:complications / Q000453:epidemiology / Q000208:ethnology*; D050177:Overweight / Q000150:complications / Q000453:epidemiology / Q000208:ethnology*; D017697:Premenopause; D018570:Risk Assessment; D012307:Risk Factors; D049629:Waist-Hip Ratio; D044465:White People / Q000706:statistics & numerical data
keywords: Breast cancer; ethnicity; obesity; overweight