Purpose: Women who smoke at breast cancer diagnosis have higher risk of breast cancer-specific and all-cause mortality than nonsmokers; however, differences by ethnicity or prognostic factors and risk for noncancer mortality have not been evaluated.
Methods: We examined associations of active and passive smoke exposure with mortality among Hispanic (n = 1020) and non-Hispanic white (n = 1198) women with invasive breast cancer in the Breast Cancer Health Disparities Study (median follow-up of 10.6 years).
Results: Risk of breast cancer-specific (HR = 1.55, 95% CI = 1.11-2.16) and all-cause (HR = 1.68, 95% CI = 1.30-2.17) mortality was increased for current smokers, with similar results stratified by ethnicity. Ever smokers had an increased risk of noncancer mortality (HR = 1.68, 95% CI = 1.12-2.51). Associations were strongest for current smokers who smoked for 20 years or more were postmenopausal, overweight and/or obese, or reported moderate and/or high alcohol consumption; however, interactions were not significant. Breast cancer-specific mortality was increased two fold for moderate and/or high recent passive smoke exposure among never smokers (HR = 2.12, 95% CI = 1.24-3.63).
Conclusions: Findings support associations of active-smoking and passive-smoking diagnosis with risk of breast cancer-specific and all-cause mortality and ever smoking with noncancer mortality, regardless of ethnicity, and other factors. Smoking is a modifiable lifestyle factor and effective smoking cessation, and maintenance programs should be routinely recommended for women with breast cancer.
Keywords: Breast cancer; Ethnicity; Hispanic; Mortality; Native American ancestry; Smoking; Survival.
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