Weight gain prior to diagnosis and survival from breast cancer.
BACKGROUND
To examine the effects of prediagnostic obesity and weight gain throughout the life course on survival after a breast cancer diagnosis, we conducted a follow-up study among a population-based sample of women diagnosed with first, primary invasive, and in situ breast cancer between 1996 and 1997 (n = 1,508).


METHODS
In-person interviews were conducted shortly after diagnosis to obtain information on height and weight at each decade of life from age 20 years until 1 year before diagnosis. Patients were followed to determine all-cause (n = 196) and breast cancer-specific (n = 127) mortality through December 31, 2002.


RESULTS
In multivariate Cox proportional hazards models, obese women had increased mortality due to breast cancer compared with ideal weight women among those who were premenopausal at diagnosis [hazard ratio (HR), 2.85; 95% confidence interval (95% CI), 1.30-6.23] and postmenopausal at diagnosis (HR, 1.91; 95% CI, 1.06-3.46). Among women diagnosed with premenopausal breast cancer, those who gained >16 kg between age 20 years and 1 year before diagnosis, compared with those whose weight remained stable (+/-3 kg), had more than a 2-fold elevation in all-cause (HR, 2.45; 95% CI, 0.96-6.27) and breast cancer-specific mortality (HR, 2.09; 95% CI, 0.80-5.48). Women diagnosed with postmenopausal breast cancer who gained more than 12.7 kg after age of 50 years up to the year before diagnosis had a 2- to 3-fold increased risk of death due to all-causes (HR, 2.69; 95% CI, 1.63-4.43) and breast cancer (HR, 2.95; 95% CI, 1.36-6.43).


CONCLUSIONS
These results indicate that high levels of prediagnostic weight and substantial weight gain throughout life can decrease survival in premenopausal and postmenopausal breast cancer patients.
Cleveland
Rebecca J
RJ
Department of Epidemiology, University of North Carolina, CB 7435 McGavran-Greenberg Hall, Chapel Hill, NC 27599-7435, USA.
Eng
Sybil M
SM
Abrahamson
Page E
PE
Britton
Julie A
JA
Teitelbaum
Susan L
SL
Neugut
Alfred I
AI
Gammon
Marilie D
MD
D001943:Breast Neoplasms / Q000175:diagnosis / Q000401:mortality* / Q000503:physiopathology*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015999:Multivariate Analysis; D009765:Obesity / Q000503:physiopathology*; D016017:Odds Ratio; D017698:Postmenopause; D017697:Premenopause; D011379:Prognosis; D012307:Risk Factors; D016019:Survival Analysis; D015430:Weight Gain