What is the current evidence between alcohol and cancer? Presentation given by Giota Mitrou PhD MSc, Head of Research Funding and Science Activities, World Cancer Research Fund International (WCRF International).

1. What is the current evidence between alcohol
and cancer?
STAP International Conference on Alcohol, Health and Policy
3 October 2014
Giota Mitrou PhD MSc
Head of Research Funding & Science Activities

2. Outline
 World Cancer Research Fund network & World Cancer
Research Fund International
 The case for cancer prevention
 The Continuous Update Project process
 The Continuous Update Project evidence
 Mechanisms
 Research issues & future research directions
 Conclusions

3. World Cancer Research Fund Network
Vision: to live in a world where no one develops a preventable cancer
Members of the World Cancer Research Fund network of cancer charities with
a global reach, dedicated to the prevention of cancer through diet, weight and
physical activity:
American Institute for Cancer Research (1982)
World Cancer Research Fund UK (1990)
World Cancer Research Fund Netherlands (1994)
World Cancer Research Fund Hong Kong (1997)
World Cancer Research Fund International (1999) leads and unifies the network
of cancer charities

4. World Cancer Research Fund
International
 Supports the scientific community in their research
 Stimulates and nurtures research and innovation in cancer
prevention and survivorship
 Encourages more young scientists to enter the field
 Encourages scientists to cite us in scientific papers and to
help disseminate our information
 Encourages and enables governments and policymakers to
adopt and implement effective policy actions
 Engages and influences decision-makers to involve us in the
development of their policies on cancer prevention and non-communicable
diseases

5. The case for cancer prevention

6. Global Alcohol Consumption
Europe: In men about
10% and in women
about 3% of all
cancers attributable to
alcohol Devaux and Sassi, OECD
Publishing, 2013.
Source: WHO's annual World Health Statistics report 2010

7. Alcohol and disease
 3rd highest risk factor for disease & mortality in Europe
 Light to moderate alcohol consumption might reduce
cardiovascular risk especially CHD mortality (reverse
causation and confounding cannot be excluded)
 High consumption might precipitate myocardial
ischemia/infarction and coronary death
 Since 1998 IARC classified alcohol as Group 1
carcinogen

8. 24
22
20
18
16
14
12
10
8
6
4
2
0
Estimated global number of new cases of cancer
(actual and predicted)
1970 1980 1990 2000 2010 2020 2030 2040
Number (millions)
Year
Data from Parkin et al, Pisani et al, Globocan 2012, IARC

9. International Agency for Research on Cancer
“We are not going to be able to address this problem by simply improving
the treatment of the disease…Prevention is absolutely critical and is
somewhat neglected…Tidal wave of cancer and restrictions on alcohol
and sugar need to be considered” – Chris Wild, Director

10. World Cancer Research Fund cancer preventability
estimates from alcohol intake
Cancer USA
(%)
UK
(%)
Brazil
(%)
China
(%)
Oesophagus 34 51 23 11
Mouth,
Pharynx &
Larynx
27 41 17 10
Liver 15 17 6 6
Colorectum 5 7 2 1
Breast 11 22 6 1
Source: http://www.wcrf.org/cancer_statistics/preventability_estimates/preventability_estimates_food.php

11. The Continuous Update Project process

12. Continuous Update Project

The Continuous Update Project analyses global cancer prevention
and survival research linked to diet, nutrition and physical activity.
Among experts worldwide it is a trusted, authoritative scientific
resource, which underpins current guidelines and policy for cancer
prevention

It ensures the World Cancer Research Fund network
Recommendations for Cancer Prevention are based on the latest
evidence

The Continuous Update Project is produced in partnership with the
American Institute for Cancer Research, World Cancer Research
Fund UK, World Cancer Research Fund NL and World Cancer
Research Fund HK

13. Continuous Update Project

Agreed process for systematically
reviewing evidence for 2007 Report

Researchers at Imperial College London:
Continuous Update Project database
of epi research
Systematically review the evidence

Expert Panel:
Draw conclusions
Make recommendations

14. People

Currently more than 100
scientists from 17
countries around the
world

International panel of 12
experts

Researchers, peer
reviewers, advisers

15. Hierarchy of evidence

Meta-analysis

RCT

Cohort

Case control

Ecological

Opinion

16. Grading criteria
Predefined requirements for;

Number and types of studies

Quality of exposure and outcome assessment

Heterogeneity within and between study types

Exclusion of chance, bias or confounding

Biological gradient

Evidence of mechanisms

Size of effect

17. Grading the evidence
Decreases
risk
Increases
risk
Strong
evidence
Convincing
Probable
Limited
evidence
Limited -
suggestive
Limited – no
conclusion
Strong
evidence
Substantial
effect on risk
unlikely
Basis for recommendations

18. The Continuous Update Project: what is
the current evidence

19. Assessing alcoholic drink intake

Alcohol is a common term for ethanol

Alcoholic drinks include beer, wine and
spirits – ethanol concentration varies

Measures of exposure:
 Number of alcoholic drinks/time period (eg
per day or per week)
 Ethanol intake (g or ml)/time period

20. Breast Cancer Report 2010

21. Breast Cancer Report 2010

22. Postmenopausal Breast Cancer & Alcohol
Relative risk:
8% per 10g ethanol/d
No. of studies: 13

23. Postmenopausal Breast Cancer & Alcohol
High vs Low intake
Direction of effect:
increased risk
Range: 0g to >60g ethanol/d
No. of studies: 13

24. Colorectal Cancer Report 2011

25. Colorectal Cancer & Alcohol by sex
Men:
Relative risk:
11% per 10g
ethanol/d
No. of studies: 7
Women:
Relative risk:
7% per 10g
ethanol/d
No. of studies: 2

26. Pancreatic Cancer Report 2012

27. Strong evidence for alcohol & other cancers
Second Expert Report 2007
Cancer site Increased risk Intake
Mouth, pharynx, larynx 24% 1 drink/week
Oesophageal 4% 1 drink/week
Liver 10% 10g/day
Note: Multiplicative synergistic effects for combined exposure to alcohol
drinking and tobacco smoking and upper respiratory tract cancers

28. Mouth, pharynx, larynx
Nasopharynx
Oesophagus
Lung
Stomach
Pancreas
Gallbladder
Liver
Colorectum7
Breast premenopause
Breast postmenopause
Ovary
Endometrium
Prostate
Kidney
Skin
Foods containing dietary fibre
Aflatoxins
Non-starchy vegetables1
Allium vegetables
Garlic
Fruits2
Foods containing lycopene
Food containing selenium3
Red meat
Processed meat
Cantonese-style salted fish
Diets high in calcium4
Salt, salted and salty foods
Glycaemic load
Arsenic in drinking water
Maté
Alcoholic drinks5
Coffee
Beta-carotene6
Physical activity
Body fatness
Adult attained height
Greater birth weight
Lactation
Convincing decreased risk
Probable decreased risk
Probable increased risk
Convincing increased risk
Substantial effect on risk unlikely
Continuous Update
Project matrix of
strong evidence

29. Recommendation for cancer
prevention

30. Publications timetable
Year Publication
2010 Breast
2011 Colorectum
2012 Pancreas
2013-14 Endometrium, ovary, breast cancer survivors, prostate
2014-15 Bladder, kidney, liver, gallbladder
2015-16 Stomach, oesophagus, lung
2016-17 Mouth, pharynx, larynx, nasopharynx, breast, colorectum
2017 Review Recommendations for Cancer Prevention

31. Mechanisms
Alcohol Cancer
?
Biological/Cellular Pathway

32. Mechanisms

Ethanol (acetaldehyde) is human carcinogen (Group
1, IARC)

Ethanol metabolism activates other pro-carcinogens
eg ROS

Disrupts folate metabolism- important in DNA
synthesis and repair

Suppresses the immune system which may facilitate
tumour cell spread

33. Cancer site specific mechanisms

Digestive tract cancers:
 Variation in ethanol metabolising enzymes (ADH, ALDH)
modulates cancer risk

Oral cavity, larynx, pharynx and oesophagus cancers:
 Synergistic effect of carcinogens in tobacco and alcoholic
drinks lead to mucosal hyperproliferation

Liver cancer:
 Mediates cirrhosis of the liver which is associated with cancer
development

Breast cancer:
 Increases oestrogen and androgen levels/induces expression
of ER/PR hormone receptors

34. Research issues and future research directions

Better standardisation across studies in assessing alcohol
intake, timing and pattern of exposure eg binge drinking

Better characterisation of cumulative lifetime exposure (better
info on age at start of drinking, assessing alcohol intake during
lifecourse, stopping drinking and risk)

Interactions with other lifestyle factors eg body weight or with
nutrients eg folate

Better understanding cancer site specific mechanisms eg
epigenetic mechanisms, main effect modifiers

Understanding individual attitudes towards alcohol drinking
and cultural and social influences for tailored public health
messages

35. Conclusions

Continuous Update Project is trusted, authoritative scientific resource,
which underpins current guidelines and policy for cancer prevention

Continuous Update Project database of evidence largest of its kind on
diet, nutrition and physical activity

Enables comprehensive recommendations for cancer prevention based
on the most up-to-date scientific evidence

Strong evidence that alcohol causes cancer of:
 Breast
 Colorectal
 Mouth, pharynx, larynx
 Oesophageal
 Liver

36. Conclusions

Risk increases in dose-dependent manner-higher amount,
higher risk of cancer development

Consumption of any amount of alcohol increases cancer risk

Reducing consumption or even better avoiding alcohol
completely will help reduce cancer risk

Important implications for prevention and alcohol policy

37. World Cancer Research Fund cancer prevention
recommendation

38. For further information
Giota Mitrou PhD
Head of Research Funding & Science Activities
g.mitrou@wcrf.org
@wcrfint
facebook.com/wcrfint
www.wcrf.org