Alcohol consumption and mortality after breast cancer diagnosis: The health and functioning in women study

Article type: Research Article

Authors: Din, Natasha^a | Allen, Isabel Elaine^a | Satariano, William A.^b | Demb, Joshua^a | Braithwaite, Dejana^{a; c; *}

Affiliations: [a] Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, USA | [b] School of Public Health, University of California, Berkeley, CA, USA | [c] Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA

Correspondence: [*] Corresponding author: Dejana Braithwaite, Department of Epidemiology and Biostatistics Mission Hall: Global Health & Clinical Science Building, UCSF 550 16th Street, 2nd Floor, San Francisco, CA, USA. Tel.: +1 415/514 8019; Fax: +1 415/514 8150; E-mail: Dejana.Braithwaite@ucsf.edu

Abstract: OBJECTIVE:To determine the association of prediagnostic alcohol consumption with long-term mortality from breast cancer and other causes in a cohort of women with breast cancer. METHODS:We studied a Michigan-based cohort of 939 women aged 40–84 years, who provided complete information about the type, amount and intensity of prediagnostic alcohol consumption. Associations of alcohol consumption, based on weekly volume of alcohol consumption during the year prior to breast cancer diagnosis, with mortality were evaluated in Cox proportional hazards models, with adjustment for sociodemographic factors, body mass index, smoking, comorbidity, tumor characteristics, and treatment. Differences among covariates were assessed with Pearson χ2 , Student t -tests and Wilcoxon Rank Sum tests. All statistical tests were two-sided. RESULTS:During a median follow-up of 11 years, 724 deaths occurred overall, with 303 from breast cancer. Fifty-five percent of the women were categorized as drinkers with volume of alcohol consumption ranging from 0.75 to 36.00 drinks/week. In multivariable models, a decreased risk of other-cause mortality was associated with low alcohol drinking (0.75–3.75 drinks/week; HR = 0.61, 95% CI = 0.47–0.78), moderate volume alcohol drinking (4.00–9.75 drinks/week; HR = 0.57, 95% CI = 0.39–0.85) and low frequency (0.75–3.75 drinks/week) beer and wine intake (HR = 0.69, 95% CI = 0.50–0.96 and HR = 0.68, 95% CI = 0.52–0.88 respectively). Although the risk of breast cancer-specific mortality was not statistically significantly associated with moderate (4.00–9.75 drinks/week) and high volume (10.00–36.00 drinks/week) alcohol drinking in the overall cohort (HR = 1.43, 95% CI = 95% 0.97–2.12 and HR = 1.53, 95% CI = 0.87–2.70 respectively), there was a positive association of alcohol consumption with breast cancer-specific mortality among current smokers (HR = 1.92, 95% CI = 1.03–3.57; P interaction = 0.04). CONCLUSION:In this prospective cohort study, regular consumption of 0.75–36.00 alcoholic drinks per week during the year prior to breast cancer diagnosis was associated with a reduction in other-cause mortality and with an increase in breast cancer-specific mortality among current smokers, after taking into account clinical and sociodemographic factors.

Keywords: Breast cancer, mortality, alcohol consumption, prospective cohort study

DOI: 10.3233/BD-150202

Journal: Breast Disease, vol. 36, no. 2-3, pp. 77-89, 2016