To the Editor: Reding et al. (1), in agreement with a recent study from the United Kingdom (2), reported that alcohol consumption may improve breast cancer survival. However, the survival advantage was only seen for wine consumption; not for beer or liquor consumption (1). It is, indeed, conceivable that factors affecting breast cancer onset (3) may also influence the course of the disease, but a survival benefit linked to alcohol consumption would have to be reconciled with a clear association with increased breast cancer risk (3).

To shed further light on this issue, we used follow-up information (median, 12.6 years) from 1,453 women median age 55 years (range, 23-74 years) with incident invasive breast cancer, diagnosed between 1991 and 1994 and interviewed in an Italian case-control study (4). We observed 503 deaths (4) and estimated the hazard ratios (HR) for all-cause mortality, and the corresponding 95% confidence intervals (CI) using Cox proportional hazard models adjusting for major tumor characteristics (tumor, node, and metastasis stage, and estrogen and progesterone receptor status) and potential lifestyle factors associated with survival (4). The standard unit of alcohol consumption was similar in our study and in the Reding et al. (1) study (12 g of pure alcohol).

The HR for drinkers in the fully adjusted model was 0.98 (95% CI, 0.79-1.22) and 1.17 (95% CI, 0.85-1.61) for ≥21 drinks/wk, compared with nondrinkers (Table 1). The corresponding figures for wine consumption, which accounted for 79% of all alcohol consumption in our study, were 0.94 (0.76-1.16) and 1.11 (0.71-1.73), respectively. In no category of alcohol consumption did drinkers survive any longer than nondrinkers (Table 1).

Table 1.

HRs and corresponding 95% CIs for all-cause mortality by alcohol consumption before and after adjustment for selected prognostic factors in 1,453 women with breast cancer in Italy

PatientsDeaths (%)HR (95% CI)*HR (95% CI)†HR (95% CI)‡
Alcohol drinking§      
Never∥ 326 120 (36.8) 1 1 1 
Ever 1,127 383 (34.0) 0.88 (0.71-1.08) 0.99 (0.80-1.22) 0.98 (0.79-1.22) 
Former 119 42 (35.3) 0.86 (0.60-1.23) 1.01 (0.70-1.45) 1.03 (0.71-1.48) 
Current (drinks/wk)      
    <7 300 98 (32.7) 0.90 (0.69-1.18) 1.03 (0.79-1.35) 1.03 (0.79-1.36) 
    7-13 294 94 (32.0) 0.77 (0.59-1.01) 0.88 (0.67-1.16) 0.89 (0.67-1.17) 
    14-20 253 87 (34.4) 0.89 (0.67-1.18) 0.95 (0.71-1.26) 0.92 (0.69-1.23) 
    ≥21 161 62 (38.5) 1.06 (0.77-1.45) 1.19 (0.87-1.64) 1.17 (0.85-1.61) 
Wine drinking§      
Never∥ 365 135 (37.0) 1 1 1 
Ever 1,088 368 (33.8) 0.85 (0.69-1.04) 0.94 (0.77-1.16) 0.94 (0.76-1.16) 
Former 117 42 (35.9) 0.85 (0.60-1.22) 0.99 (0.69-1.41) 1.00 (0.70-1.44) 
Current (drinks/wk)      
    <7 290 92 (31.7) 0.82 (0.63-1.08) 0.95 (0.72-1.24) 0.94 (0.72-1.24) 
    7-13 289 93 (32.2) 0.76 (0.58-0.99) 0.85 (0.65-1.11) 0.86 (0.66-1.13) 
    14-20 326 117 (35.9) 0.92 (0.71-1.19) 0.98 (0.76-1.27) 0.96 (0.74-1.25) 
    ≥21 66 24 (36.4) 1.03 (0.66-1.59) 1.17 (0.76-1.83) 1.11 (0.71-1.73) 
PatientsDeaths (%)HR (95% CI)*HR (95% CI)†HR (95% CI)‡
Alcohol drinking§      
Never∥ 326 120 (36.8) 1 1 1 
Ever 1,127 383 (34.0) 0.88 (0.71-1.08) 0.99 (0.80-1.22) 0.98 (0.79-1.22) 
Former 119 42 (35.3) 0.86 (0.60-1.23) 1.01 (0.70-1.45) 1.03 (0.71-1.48) 
Current (drinks/wk)      
    <7 300 98 (32.7) 0.90 (0.69-1.18) 1.03 (0.79-1.35) 1.03 (0.79-1.36) 
    7-13 294 94 (32.0) 0.77 (0.59-1.01) 0.88 (0.67-1.16) 0.89 (0.67-1.17) 
    14-20 253 87 (34.4) 0.89 (0.67-1.18) 0.95 (0.71-1.26) 0.92 (0.69-1.23) 
    ≥21 161 62 (38.5) 1.06 (0.77-1.45) 1.19 (0.87-1.64) 1.17 (0.85-1.61) 
Wine drinking§      
Never∥ 365 135 (37.0) 1 1 1 
Ever 1,088 368 (33.8) 0.85 (0.69-1.04) 0.94 (0.77-1.16) 0.94 (0.76-1.16) 
Former 117 42 (35.9) 0.85 (0.60-1.22) 0.99 (0.69-1.41) 1.00 (0.70-1.44) 
Current (drinks/wk)      
    <7 290 92 (31.7) 0.82 (0.63-1.08) 0.95 (0.72-1.24) 0.94 (0.72-1.24) 
    7-13 289 93 (32.2) 0.76 (0.58-0.99) 0.85 (0.65-1.11) 0.86 (0.66-1.13) 
    14-20 326 117 (35.9) 0.92 (0.71-1.19) 0.98 (0.76-1.27) 0.96 (0.74-1.25) 
    ≥21 66 24 (36.4) 1.03 (0.66-1.59) 1.17 (0.76-1.83) 1.11 (0.71-1.73) 
*

Estimates from the Cox proportional hazard model adjusted for region of residence, age at diagnosis, and year of diagnosis.

†

Estimates from the Cox proportional hazard model adjusted for region of residence, age at diagnosis, year of diagnosis, tumor, node, and metastasis stage, and estrogen and progesterone receptor status.

‡

Estimates from the Cox proportional hazard model adjusted for region of residence, age at diagnosis, year of diagnosis, tumor, node and metastasis stage, estrogen and progesterone receptor status, body mass index, and smoking habit.

§

One drink = 12 g of pure alcohol.

∥

Reference category.

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Our present study does not lend support to the possibility that alcohol or wine consumption improves the survival of women with breast cancer. Compared with Reding et al. (1), our study had a similar magnitude and length of follow-up but included a wider age range. Drinking ≥7 units per week was more commonly reported by women from Italy (49%) than those from the United States (19%). Furthermore, contrary to the United States (5), wine consumption in Italy is not affected by educational level or social class (4). It is, therefore, less likely that alcohol consumption is related to earlier diagnosis or better cancer treatment in Italy than in the United States.

In conclusion, the comparison of findings in populations in which scope for bias and confounding is different can help to interpret the influence of lifestyle factors on cancer survival.

Ettore Bidoli, Mauro Lise, Jerry Polesel, and Diego Serraino (IRCCS Centro di Riferimento Oncologico, Aviano); Cristina Bosetti, Carlotta Galeone, Silvano Gallus, Carlo La Vecchia, Eva Negri, and Claudio Pelucchi (“Mario Negri” Institute, Milan); Loris Zanier (Agenzia Regionale della Sanità, Udine); Margherita de Dottori (INSIEL, Udine); Carmen F. Stocco and Paola Zambon (Registro Tumori del Veneto, Padua); Antonella Puppo and Marina Vercelli (Registro Tumori Ligure, Genoa); and Fabio Falcini and Alessandra Ravaioli (Registro Tumori della Romagna, Forlì).

No potential conflicts of interest were disclosed.

Grant support: Italian Association for Research on Cancer.

1
Reding KW, Daling JR, Doody DR, et al. Effect of prediagnostic alcohol consumption on survival after breast cancer in young women.
Cancer Epidemiol Biomarkers Prev
 
2008
;
17
:
1988
–96.
2
Barnett GC, Shah M, Redman K, et al. Risk factors for the incidence of breast cancer: do they affect survival from the disease?
J Clin Oncol
 
2008
;
26
:
3310
–6.
3
Collaborative Group on Hormonal Factors in Breast Cancer. Alcohol, tobacco and breast cancer-collaborative reanalysis of individual data from 53 epidemiological studies, including 58,515 women with breast cancer and 95,067 women without the disease.
Br J Cancer
 
2002
;
11
:
1234
–45.
4
Dal Maso L, Zucchetto A, Talamini R, et al. Effect of obesity and other lifestyle factors on mortality in women with breast cancer.
Int J Cancer
 
2008
;
123
:
2188
–94.
5
McCann SE, Sempos C, Freudenheim JL, et al. Alcoholic beverage preference and characteristics of drinkers and nondrinkers in western New York (United States).
Nutr Metab Cardiovasc Dis
 
2003
;
13
:
2
–11.
American Association for Cancer Research
2009