Alcohol attributable burden of incidence of cancer in eight European countries based on results from prospective cohort study
1Department of Epidemiology, German Institute of Human Nutrition Potsdam-Rehbruecke, 14558 Nuthetal, Germany
2Centre for Addiction and Mental Health (CAMH), Toronto, Canada
3Institute for Clinical Psychology and Psychotherapy, TU Dresden, Germany
4Institute of Cancer Epidemiology, Danish Cancer Society, Copenhagen
5Department of Clinical Epidemiology, Aarhus University Hospital, Aalborg, Denmark
6Department of Epidemiology, School of Public Health, Aarhus University, Aarhus
7Centre for Research in Epidemiology and Population Health, U1018, Institut Gustave Roussy, F-94805, Villejuif, France
8Paris South University, UMRS 1018, F-94805, Villejuif
9WHO Collaborating Center for Food and Nutrition Policies, Department of Hygiene, Epidemiology and Medical Statistics, University of Athens Medical School and Hellenic Health Foundation, Greece
10WHO Collaborating Centre for Food and Nutrition Policies, Department of Hygiene, Epidemiology and Medical Statistics, University of Athens Medical School
11Division of Cancer Epidemiology, German Cancer Research Centre, Heidelberg, Germany
12Molecular and Nutritional Epidemiology Unit, Cancer Research and Prevention Institute, Florence, Italy
13Department of Preventive and Predictive Medicine, Epidemiology Unit, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy
14Cancer Registry and Histopathology Unit “Civile M.P.Arezzo” Hospital, ASP 7 Ragusa, Italy
15Institute for Scientific Interchange Foundation, Turin, Italy
16Public Health and Participation Directorate, Health and Health Care Services Council, Asturias, Spain
17Unit of Nutrition, Environment and Cancer, Cancer Epidemiology Research Programme, Catalan Institute of Oncology (IDIBELL), Barcelona, Spain
18Andalusian School of Public Health, Granada (Spain) and CIBER de Epidemiología y Salud Pública (CIBERESP), Spain
19Public Health Department of Gipuzkoa and CIBERESP, San Sebastian, Spain
20Department of Epidemiology, Murcia Regional Health Council, Murcia, Spain
21CIBER Epidemiología y Salud Pública (CIBERESP), Spain
22Centre for Health Sciences and Primary Care, University Medical Centre, Utrecht, Netherlands
23Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
24MRC Epidemiology Unit, Cambridge
25Cancer Epidemiology Unit, Nuffield Department of Clinical Medicine, University of Oxford, Oxford
26International Agency for Research on Cancer, IARC, Lyon, France
27Tisch Cancer Institute, Mount Sinai School of Medicine, New York, NY, USA
28Department of Epidemiology and Biostatistics, School of Public Health, Imperial College, London
Accepted January 4, 2011.
Across the countries investigated, alcohol consumption followed a north south gradient with Greece and Spain having the highest proportions of never and former consumers, and Denmark and Germany having the highest proportion of lifetime consumers (table 1). This gradient was also seen for the proportions of alcohol consumption higher than the recommended upper limit with Greece and Spain showing the lowest and Germany and Denmark the highest proportions.
Table 1 Proportions of never, former, and lifetime consumers of alcohol and mean alcohol consumption in lifetime consumers in general adult population aged 15 years or older
Among male and female lifetime consumers, the risk for all the cancers we included increased with each additional drink a day (table 2). Former consumption compared with never was associated with a considerably higher risk for total and alcohol related cancer in men. We could not compute the risk for former consumers of alcohol and upper aerodigestive tract and liver cancer in men because of low number of cases in those who had never consumed alcohol. Hence, we computed alcohol attributable fractions for upper aerodigestive tract and liver cancer in men based on the hazard rate ratio for former alcohol consumption and total cancer.
Table 2 Adjusted hazard rate ratios (HRRs)* (95% confidence intervals) per 12 g/day increment for lifetime consumers and for former versus never consumers (reference category) of alcohol
If we assume causality, these estimates would translate into 10% (95% confidence interval 7% to 13%) of total cancer in men (table 3) and 3.0% (1% to 5%) of total cancer in women (table 4) being attributable to alcohol consumption in these selected European countries. In both sexes the alcohol attributable fraction was highest for cancer of the upper aerodigestive tract (44% (31% to 56%) in men; 25% (5% to 46%) in women), followed by liver cancer (33% (11% to 54%) and 18% (−3% to 38%), respectively). Alcohol consumption was associated with 17% (10% to 25%) of cases of colorectal cancer in men and 4% (−1% to 10%) in women. Also, 5% (2% to 8%) of cases of breast cancer in women could be associated with total alcohol consumption. The alcohol attributable fractions varied across countries because of the differences in alcohol exposure, with relatively high alcohol attributable fractions for Spanish men compared with men in other countries. Confidence intervals of the alcohol attributable fractions, however, overlapped for all countries in both men and women.
Proportion of cancer cases attributable to alcohol use in men aged ≥15 years. Figures are percentages (95% confidence interval)
Table 4 Proportion of cancer cases attributable to alcohol use in women aged ≥15 years. Figures are percentages (95% confidence interval)
Partial attributable fractions for alcohol consumption higher than two drinks a day in men accounted for 10% of colorectal cancer, 27% of liver cancer, and 38% of upper aerodigestive tract cancer (fig 2), which accounted for 57% to 87% of the total alcohol attributable fractions. The proportion of cancer associated with alcohol consumption higher than the recommended upper limit did not vary much by country in men, except for Greece and Spain, where partial alcohol attributable fractions were somewhat lower because of the lower proportions of men consuming more than two drinks a day. In women, partial alcohol attributable fractions accounted for 3% of colorectal cancer, 4% of breast cancer, 7% of liver cancer, and 25% of upper aerodigestive tract cancer (fig 3), which accounted for 40% to 98% of the total alcohol attributable fractions. For all cancers investigated in women, the partial alcohol attributable fraction was lowest in Spain, Greece, and Italy and highest in Germany, Denmark, and the UK. When we compared total with partial alcohol attributable fractions, a substantial part (40-98%) of the incidence of alcohol attributable cancer occurred because of alcohol consumption higher than the recommended upper limit in both men and women. The remaining part of the total alcohol attributable fraction (2-60%) was associated with consumption of less than the recommended upper limit and former consumption. In men, about three in 100 alcohol related cancer cases were associated with alcohol consumption of ≤24 g/day and more than 18 in 100 were associated with alcohol consumption >24 g/day. In women one in 100 alcohol attributable cancer cases was associated with alcohol consumption of ≤12 g/day and about four in 100 associated with alcohol consumption >12 g/day.
Fig 2 Total and partial alcohol attributable fractions with 95% confidence intervals and corresponding number of cases of cancer with 95% confidence intervals in men in selected EPIC countries (Italy, Spain, UK, Greece, Germany, Denmark) in 2008. UADT=upper (more ...)
Fig 3 Total and partial alcohol attributable fractions with 95% confidence intervals and corresponding number of cases of cancer with 95% confidence intervals in women in selected EPIC countries (France, Italy, Spain, UK, Netherlands, Greece, Germany, (more ...)
In terms of total numbers of cases of alcohol related cancer, and if we accept that there is a causal association between alcohol consumption and occurrence of cancer, in 2008, 33
037 of 178
578 alcohol related cancer cases in men and 17
470 of 397
043 alcohol related cancer cases in women were associated with alcohol consumption of more than two (one for women) drinks a day. Cancer of the upper aerodigestive tract accounted for the highest number of alcohol attributable cases in men (22
022 cases), with Germany showing most cases (table 5). In women, breast cancer contributed most to the number of alcohol attributable cancer cases with 12
589 cases (fig 2, table 5 ). The numbers of total alcohol attributable cancer cases varied considerably by country, mainly because of different population sizes in the investigated countries but also because of varying alcohol attributable fractions across the countries.
Table 5 Total number* of alcohol attributable cancer cases for general population in 2008 in selected countries
The sensitivity analysis using the alcohol consumption data in the cancer cases only had similar results to those in tables 3 and 4 (data not shown). The maximum deviation was 3 percentage points in men for alcohol related cancers (29% v 32%) and 2 percentage points in women for upper aerodigestive tract cancer (23% v 25%).
Given there is a causal association between alcohol consumption and risk of cancer in people who have never smoked, sensitivity analyses with the hazard rate ratios of never smokers indicated noticeable differences compared with alcohol attributable fractions that were based on hazard rate ratios adjusted for smoking from the total cohort, particularly for liver cancer, for which the alcohol attributable fraction in men who had never smoked (AAFSens) was 78% compared with 33% in the total population, and for upper aerodigestive tract cancer, for which the AAFSens was 14% compared with 44%. The alcohol attributable fractions for colorectal cancer in women differed by 3 percentage points with AAFSens 1% v 4%, which was, however, within the confidence interval computed for the alcohol attributable fraction based on estimates of the total cohort.