Poster Topical Area: Nutritional Epidemiology
Location: Hall D
Poster Board Number: 785
Objectives: There is evidence that soft drinks are associated with increased risk of breast cancer. However, there are no previous studies investigating pre-diagnostic consumption of soft drinks and mortality after breast cancer diagnosis.
Methods: We examined the association between frequency of pre-diagnostic soft drink consumption and breast cancer mortality in 921 women with primary, incident, histologically confirmed breast cancer diagnosed between 1996 and 2001. Vital status was determined through December 31, 2013, using the National Death Index. Diet in the 12-24 months before diagnosis, including frequency of soft drink intake, was assessed using a food frequency questionnaire. Potential confounders were evaluated from an extensive epidemiologic interview and abstracted clinical data. Hazard ratios (HR), and 95% confidence intervals (CI) for soft drink consumption with all-cause, all-cancer and breast cancer mortality were estimated using Cox proportional hazards models, adjusting for age, race, education, body-mass index (BMI), energy intake, alcohol drinking, smoking, tumor stage at diagnosis and physical activity. Women with diabetes were excluded and stage 0 breast cancer diagnosis were excluded.
Results:Of the 921 women with complete information, 287 had died by the end of follow-up; of those, 138 died of breast cancer. Compared to those who reported never/rare soft drink consumption (< 1 time per month), women who had highest consumption frequency (≥5 times per week), had a statistically significant increase in the risk of breast-cancer mortality (HR=1.72, 95% CI: 1.06, 2.79; P-trend= 0.01), and all-cancer mortality (HR=1.67 95% CI: 1.08, 2.59; P-trend= 0.03), but not all-cause mortality (HR=1.31, 95% CI: 0.90, 1.90; P-trend= 0.14). Among pre-menopausal women (n=64), those with more frequent soft drink consumption, compared to never/rare consumers, had significantly higher risk for all-cause (HR=2.85, 95% CI: 1.30, 6.26; P-trend= 0.01), breast cancer (HR=2.71, 95%CI: 1.13, 6.50; P-trend= 0.03), and all-cancer mortality (HR=2.85, 95%CI: 1.24, 6.59; P-trend= 0.01). Conversely, among postmenopausal women (n=223), frequency of soft drink consumption was not associated with the risk of all-cause, all-cancer, or breast cancer mortality (P-trend>0.05).
Conclusions: Our results suggest that higher intakes of soft drinks may be associated with lower survival among women diagnosed with breast cancer, especially pre-menopausal women.
Supported in part by grants DAMD17-96-1-6202US from the Army Medical Research and Materiel Command, and R01CA92040 from the NIH.
B. Nadia Koyratty
University at Buffalo
Buffalo, New York