Obesity and mortality after breast cancer by Race/Ethnicity: The california breast cancer survivorship consortium

Marilyn L. Kwan, Esther M. John, Bette J. Caan, Valerie S. Lee, Leslie Bernstein, Iona Cheng, Scarlett Lin Gomez, Brian E. Henderson, Theresa H Keegan, Allison W. Kurian, Yani Lu, Kristine R. Monroe, Janise M. Roh, Salma Shariff-Marco, Richard Sposto, Cheryl Vigen, Anna H. Wu

Research output: Contribution to journalArticlepeer-review

58 Scopus citations

Abstract

We investigated body size and survival by race/ethnicity in 11,351 breast cancer patients diagnosed from 1993 to 2007 with follow-up through 2009 by using data from questionnaires and the California Cancer Registry. We calculated hazard ratios and 95% confidence intervals from multivariable Cox proportional hazard model-estimated associations of body size (body mass index (BMI) (weight (kg)/height (m)2) and waist-hip ratio (WHR)) with breast cancer-specific and all-cause mortality. Among 2,744 ascertained deaths, 1,445 were related to breast cancer. Being underweight (BMI <18.5) was associated with increased risk of breast cancer mortality compared with being normal weight in non-Latina whites (hazard ratio (HR) = 1.91, 95% confidence interval (CI): 1.14, 3.20), whereas morbid obesity (BMI ≥40) was suggestive of increased risk (HR = 1.43, 95% CI: 0.84, 2.43). In Latinas, only the morbidly obese were at high risk of death (HR = 2.26, 95% CI: 1.23, 4.15). No BMI-mortality associations were apparent in African Americans and Asian Americans. High WHR (quartile 4 vs. quartile 1) was associated with breast cancer mortality in Asian Americans (HR = 2.21, 95% CI: 1.21, 4.03; P for trend = 0.01), whereas no associations were found in African Americans, Latinas, or non-Latina whites. For all-cause mortality, even stronger BMI and WHR associations were observed. The impact of obesity and body fat distribution on breast cancer patients' risk of death may vary across racial/ethnic groups.

Original languageEnglish (US)
Pages (from-to)95-111
Number of pages17
JournalAmerican Journal of Epidemiology
Volume179
Issue number1
DOIs
StatePublished - Jan 1 2014
Externally publishedYes

Keywords

  • adiposity
  • body mass index
  • breast cancer
  • mortality
  • obesity
  • race/ethnicity
  • survival
  • waist-hip ratio

ASJC Scopus subject areas

  • Epidemiology

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