what is the current evidence between alcohol and cancer (stap international conference on alcohol,...
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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
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
World Cancer Research Fund Network
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)
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:
World Cancer Research Fund International (1999) leads and unifies the network
of cancer charities
Vision: to live in a world where no one develops a preventable cancer
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
The case for cancer prevention
Global Alcohol Consumption
Source: WHO's annual World Health Statistics report 2010
Europe: In men about
10% and in women
about 3% of all
cancers attributable to
alcohol Devaux and Sassi, OECD
Publishing, 2013.
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
0
2
4
6
8
10
12
14
16
18
20
22
24
1970 1980 1990 2000 2010 2020 2030 2040
Nu
mb
er
(mil
lio
ns
)
Year
Estimated global number of new cases of cancer (actual and predicted)
Data from Parkin et al, Pisani et al, Globocan 2012, IARC
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 alcoholand sugar need to be considered” – Chris Wild, Director
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 1Source: http://www.wcrf.org/cancer_statistics/preventability_estimates/preventability_estimates_food.php
The Continuous Update Project process
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
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
People
Currently more than 100
scientists from 17
countries around the
world
International panel of 12
experts
Researchers, peer
reviewers, advisers
Hierarchy of evidence
Meta-analysis
RCT
Cohort
Case control
Ecological
Opinion
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
Grading the evidenceDecreases
risk
Increases
risk
Strong
evidence
Convincing
Probable
Limited
evidence
Limited -
suggestive
Limited – no
conclusion
Strong
evidence
Substantial
effect on risk
unlikely
Basis for recommendations
The Continuous Update Project: what is the current evidence
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
Breast Cancer Report 2010
Breast Cancer Report 2010
Postmenopausal Breast Cancer & Alcohol
Relative risk:
8% per 10g ethanol/d
No. of studies: 13
Postmenopausal Breast Cancer & AlcoholHigh vs Low intake
Direction of effect:
increased risk
Range: 0g to >60g ethanol/d
No. of studies: 13
Colorectal Cancer Report 2011
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
Pancreatic Cancer Report 2012
Strong evidence for alcohol & other cancersSecond 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
Mouth
, phary
nx, la
rynx
Naso
phary
nx
Oeso
phagus
Lung
Sto
mach
Pancr
eas
Gallbla
dder
Liv
er
Colo
rect
um
7
Bre
ast
pre
menopause
Bre
ast
post
menopause
Ovary
Endom
etr
ium
Pro
state
Kid
ney
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
Coffee
Beta-carotene6
Physical activity
Body fatness
Adult attained height
Greater birth weight
Lactation
Alcoholic drinks5
Convincing decreased risk
Probable decreased risk
Probable increased risk
Convincing increased riskSubstantial effect on risk unlikely
Continuous Update
Project matrix of
strong evidence
Recommendation for cancer
prevention
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
Publications timetable
Mechanisms
Alcohol Cancer
Biological/Cellular Pathway
?
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
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
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 egepigenetic mechanisms, main effect modifiers
Understanding individual attitudes towards alcohol drinking and cultural and social influences for tailored public health messages
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
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
World Cancer Research Fund cancer prevention recommendation
For further information
@wcrfint
facebook.com/wcrfint
www.wcrf.org
Giota Mitrou PhD
Head of Research Funding & Science Activities