Annals of Oncology 14:973-1005, 2003
© 2003 European Society for Medical Oncology
Original Paper |
European Code Against Cancer and scientific justification: third version (2003)
1 Department of Epidemiology and Biostatistics, European Institute of Oncology, Milan, Italy; 2 Centre for Research on Epidemiology and Health Information Systems (CRESIS), Centre de Recherche Public de la Santé, Luxembourg; 3 Professor and Chairman, Radiotherapy Department, The Netherlands Cancer Institute, Antoni van Leeuwenhoek Huis, Amsterdam, The Netherlands; 4 Medical Oncology Service, Vall d"Hebron University Hospital, Vall d"Hebron, Barcelona, Spain; 5 Chief, Unit of Environmental Cancer Epidemiology, International Agency for Research on Cancer, Lyon, France; 6 Cancer Family Network, CancerResearchUK, University of Newcastle, Newcastle, UK; 7 Chief Administrative Medical Officer, Greater Glasgow Health Board, Glasgow, UK; 8 President, The Association of European Cancer Leagues, Oslo, Norway; 9 Oncology Centre Antwerp, Antwerp, Belgium; 10 Hematology-Oncology, Centre Hospitalier, Luxembourg; 11 Med. Klinic 1, Universitat zu Koln, Koln, Germany; 12 Clinical Trial Service Unit, Cancer Research UK Cancer Studies Unit, Radcliffe Infirmary, Oxford, UK; 13 Chief, Field and Intervention Studies Unit, IARC, Lyon, France; 14 Scientific Coordinator, Department of Epidemiology and Biostatistics, European Institute of Oncology, Milan, Italy; 15 Department of Epidemiology and Biostatistics, European Institute of Oncology, Milan, Italy; 16 Lithuanian Oncology Center, Vilnius, Lithuania; 17 Deputy Director, Cancer Research UK & UCL Cancer Trials Centre, Stephenson House, London, UK; 18 Director, National Institute of Oncology, Budapest, Hungary; 19 Department of Epidemiology and Public Health, Institut Municipal d’Investigacio Mèdica (IMIM), Barcelona, Spain; 20 Department of Oncology, Haukaland Hospital, Bergen, Norway; 21 Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy; 22 Director, Registre Vaudois des Tumeurs, Institut Universitaire de Médecine Sociale et Préventive, Lausanne, Switzerland; 23 Scientific Coordinator, Department of Epidemiology and Biostatistics, European Institute of Oncology, Milan, Italy; 24 Unit of Clinical Epidemiology, Department of Epidemiology and Biostatistics, European Institute of Oncology, Milan, Italy; 25 Director-General of Public Health, Ministerio de Sanidad y Consumo, Madrid, Spain; 26 Genetic Epidemiology Division, Cancer Research UK, St James’s University Hospital, Leeds, UK; 27 Ministero della Sanita’, Roma, Italy; 28 Chairman, Department of Urology, Hopital de l’Antiquaille, Lyon, France; 29 Director, National Cancer Intelligence Centre, Office for National Statistics, B6/02, 1 Drummond Gate, London, UK; 30 National Cancer Director, St Thomas’ Hospital, London, UK; 31 Department of Oncology, Radiumhemmet, Karolinska Hospital, Stockholm; 32 Dean and Director of Studies and Research, Eastman Dental Institute for Oral Health Care Sciences and International Centres for Excellence in Dentistry, University of London, Eastman Dental Institute, London, UK; 33 President, Liga proti rakovine SR, Bratislava, Slovakia; 34 Danish Cancer Society, Director Cancer Prevention and Documentation, Copenhagen, Denmark; 35 President du Centre Antoine Beclere, Centre Antoine Beclere, Faculte’ de Medicine, Paris, France; 36 Director, Institut Gustave Roussy, Villejuif, France; 37 Scientific Director, European Institute of Oncology, Milan, Italy; 38 The Medical College of St Bartholomew’s Hospital, Wolfson Institute of Preventive Medicine, Department of Epidemiology, London, UK; 39 Schweizerische Krebsliga, Berne, Switzerland; 40 Director, Institute of Carcinogenesis, Deputy Director, Cancer Research Centre RAMS, Moscow, Russian Federation; 41 Department of Cancer Epidemiology and Prevention, The Marie-Sklodowska Memorial, Cancer Center and Institute of Oncology, Warsaw, Poland; 42 Director, German Cancer Research Center (DKFZ), Heidelberg, Germany
Received 28 April 2003; accepted 7 May 2003
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Introduction |
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 Top Introduction Many aspects of general...1. Do not smoke; if...2. Avoid obesity.3. Undertake some brisk,...4. Increase your daily...5. If you drink alcohol,...6. Care must be taken...7. Apply strictly...There are public health...8. Women from 25 years...9. Women from 50 years...10. Men and women from...11. Participate in...Additional items consideredGeneticsCancer mortality trendsFuture directionsSuggested readingReferences |
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Since the previous version of the European Code Against Cancer was created [1], the European Union has expanded its number of Member States and next year (in 2004) will see a further and dramatic expansion as 10 new Member States join (Cyprus, Czech Republic, Hungary, Estonia, Malta, Latvia, Lithuania, Poland, Slovenia and Slovakia). Additionally, it is currently anticipated that Bulgaria and Romania will be admitted in 2007 followed at a later date by Turkey. These expansions enlarge the Union to incorporate a greater diversity of peoples with a much larger degree of heterogeneity present in lifestyle habits and disease risk than previously present. The contrast between the Mediterranean countries, the Nordic countries and those countries of Central and Eastern Europe is considerable. In view of the accession of new States, an important aspect of the revision of this Code was to take into consideration the specific situation in new Member States.
For the purposes of this text, the European Union shall be defined as the 15 current Member States (Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, The Netherlands, Portugal, Spain, Sweden and the UK) plus the 10 Accession Countries scheduled for entry in 2004 (Cyprus, Czech Republic, Hungary, Estonia, Malta, Latvia, Lithuania, Poland, Slovenia and Slovakia).
European Union cancer burden
In the European Union in 2000, it is estimated that there were 1 892 000 incident cases of all forms of cancer (excluding non-melanoma skin cancers) diagnosed (Table 1): this burden was shared almost equally by each gender, although there was a slight excess in men (1 014 000 cases) over women (878 000 cases). In 2000, it is estimated that there were 1 156 000 deaths in the European Union where cancer was the underlying cause. Of these, 651 000 were of men and 504 000 women (Table 1).
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The commonest form of cancer diagnosed in the European Union in 2000 was colorectal cancer, with an estimated total of 258 000 new cases. Of these, 123 000 were diagnosed in men while 135 000 were in women (Table 2). There was a total of 138 000 deaths caused by colorectal cancer in the European Union, of which 70 000 were of men and 68 000 women (Table 2).
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In 2000, it is estimated that there were 241 000 incident cases of lung cancer, with the majority diagnosed in men (192 000 cases) and fewer in women (49 000 cases) (Table 3). In the same year, it is estimated that there were 231 000 deaths in the European Union caused by lung cancer. Of these, 183 000 occurred in men and 49 000 in women.
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There was an estimated 95 500 incident cases of stomach cancer diagnosed in 2000, of which 57 000 were diagnosed in men and 38 000 in women (Table 4). There was an estimated total of 78 000 deaths caused by stomach cancer: 45 000 in men and 32 500 in women (Table 4).
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In women, there was an estimated 244 500 new cases of breast cancer diagnosed in the year 2000 and there were 91 000 deaths caused by breast cancer (Table 5). In men, there was an estimated total of 157 000 incident cases of prostate cancer diagnosed in the European Union in 2000 and an estimated 66 500 deaths caused by this disease (Table 5).
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The age-adjusted risk of cancer increases quite quickly with age [2]: there is a difference of at least two orders of magnitude between the risk of developing cancer in the fourth decade of life and the eighth decade of life. Even if age-specific cancer rates remain fixed at 1980 levels, it is to be expected that there will be large increases in the numbers of cases of cancer diagnosed for the first two decades of the twenty-first century. This is simply a consequence of the ageing population; more and more men and women living to older and older ages. The postworld war II ‘baby-boom’, the first generation in Western Europe to have had the benefit of modern medicine and not to have endured a major war, will reach ages where cancer is an important problem from the early days of this century. The effect on the absolute numbers of cases will be quite dramatic, particularly for cancer sites, such as prostate cancer, where the median age at diagnosis is currently
75 years, in the European Union [3].
Cancer control
The diseases grouped under the title ‘cancer’ are remarkably common and of major public health importance since more than half the people who develop cancer die from their disease. Thus, the concept of ‘cancer control’ has been developed to attack the cancer problem at various points in its evolution, with the overall goal of reducing cancer related suffering and death.
Primary prevention. The most obvious ways to prevent people dying from cancer are either to find cures for the different forms of the disease, or to find ways to stop the development of clinical cancer in the first instance. At the present time, cancer prevention involves determining the causes of cancer (risk determinants) from among those factors shown to be associated with the development of the disease by epidemiological studies (risk factors). Avoiding exposure to risk determinants would result in a reduction in cancer risk.
The evidence that cancer is preventable is compelling. Different populations around the world experience different levels of different forms of cancer [4], and these levels change with time in orderly and predictable manners [5]. Groups of migrants quickly leave behind the cancer levels of their original home and acquire the cancer pattern of their new residence, sometimes within one generation [6, 7]. Thus, those Japanese who left Japan for California left behind the high levels of gastric cancer in their homeland and exchanged it for the high levels of breast and colorectal cancer present among inhabitants of their new home. Furthermore, groups whose lifestyle habits differentiate themselves from other members of the same community frequently have different cancer risks (c.f. Seventh Day Adventist and Mormons [8]).
For reasons such as these, it is estimated that upwards of 80%, or even 90%, of cancers in western populations may be attributable to environmental causes [9]; defining ‘environment’ in its broadest sense to include a wide range of ill-defined dietary, social and cultural practices. Although all of these avoidable causes have not yet been clearly identified, it is thought that risk determinants currently exist for about one half of cancers. Thus, primary prevention in the context of cancer is an important area of public health.
Secondary prevention. It is very frequently the case that the probability of successful treatment of cancer is increased, sometimes very substantially, if the cancer can be diagnosed at an early stage. Awareness of the significance of signs and symptoms is important, but all too frequently cancers that exhibit symptoms are at an advanced stage. ‘Screening’ is a term frequently applied to the situation where tests are used to indicate whether an (generally asymptomatic) individual has a high or low chance of having a cancer. Detecting cancers at an early, asymptomatic stage could lead to decreases in the mortality rates for certain cancers, particularly for those forms of cancer in which early detection prevents metastatic dissemination.
Tertiary prevention. An obvious way to prevent cancer death is to cure those cancers which develop. However, there have been few major breakthroughs in cancer treatment, in the sense of turning a fatal tumour into a curable one. Notable successes have been in testicular teratoma [10], Hodgkin’s disease (HD) [11], childhood leukaemia, Wilm’s tumour and choriocarcinoma. Progress in survival from the major cancers has been very much less than hoped. Adjuvant chemotherapy and tamoxifen have improved survival in breast cancer [12], adjuvant chemotherapy has also contributed to improvements in the prognosis of ovarian cancer and colorectal cancer [13], and there has been some other progress that could be attributed specifically to certain treatments.
General progress in medical science has led to modern anaesthesia making more patients candidates for surgery and surgery safer, better control of infection and bacterial diseases, better imaging has improved tumour localisation and staging, and better devices are available to deliver the appropriate doses of radiation and drugs. Thus, more patients can receive better and more appropriate therapy and, hence, have a better prognosis.
The quality-of-life issue has not been neglected, with breast conservation therapy now almost supplanting traditional radical mastectomy in the majority of women; more plastic breast reconstruction; less amputation of limbs for bone and soft-tissue sarcomas; and better colostomies, being some important advances.
Against this background of cancer as an important public health problem and one of the commonest causes of premature and avoidable death in Europe, the European Code Against Cancer was introduced as a series of recommendations which, if followed, could lead in many instances to a reduction in cancer incidence and also to reductions in cancer mortality.
The European Code Against Cancer was originally drawn-up, and subsequently endorsed by the European Commission high-level Committee of Cancer Experts, in 1987. In 1994, the European Commission invited the European School of Oncology to assemble a group of international experts to examine, and consider revision of, the scientific aspects of the recommendations given in the current code. This exercise took place and a new version was adopted by the Cancer Experts Committee at its meeting in November 1994 [1].
This publication constitutes the second revision, producing the third version, of the European Code Against Cancer. The project was funded by the Europe Against Cancer programme of the European Commission. An Executive Committee was formed to guide the project and the committee involved public health specialists, oncologists, as well as representatives of the Cancer Leagues and the Prevention Departments of Ministries of Health in Europe. A Scientific Committee was established comprising several independent experts and nominated chairmen of the sub-committees established to review recommendations on specific topics. More than 100 medical scientists contributed to the development of this revision. Below the scientific rationale for each recommended point of the European Code Against Cancer is outlined, as well as discussion of other factors that were considered but not included in the code.
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Many aspects of general health can be improved, and many cancer deaths prevented, if we adopt healthier lifestyles |
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TopIntroductionMany aspects of general...1. Do not smoke; if...2. Avoid obesity.3. Undertake some brisk,...4. Increase your daily...5. If you drink alcohol,...6. Care must be taken...7. Apply strictly...There are public health...8. Women from 25 years...9. Women from 50 years...10. Men and women from...11. Participate in...Additional items consideredGeneticsCancer mortality trendsFuture directionsSuggested readingReferences |
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Any recommendation made to reduce cancer occurrence should not be one which could lead to an increased risk of other diseases. The recommendations which comprise the revised European Code Against Cancer should, if followed, also lead to improvements in other aspects of general health (Table 6). It is also important to recognise from the outset that each individual has choices to make about their lifestyle, some of which could lead to a reduction in their risk of developing cancer. These choices, and the rationale underlying their recommendation, are presented below.
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1. Do not smoke; if you smoke, stop doing so. If you fail to stop, do not smoke in the presence of non-smokers. |
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TopIntroductionMany aspects of general...1. Do not smoke; if...2. Avoid obesity.3. Undertake some brisk,...4. Increase your daily...5. If you drink alcohol,...6. Care must be taken...7. Apply strictly...There are public health...8. Women from 25 years...9. Women from 50 years...10. Men and women from...11. Participate in...Additional items consideredGeneticsCancer mortality trendsFuture directionsSuggested readingReferences |
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It is estimated that between 25 and 30% of all cancer deaths in developed countries are tobacco-related. From the results of studies conducted in Europe, Japan and North America, between 87 and 91% of lung cancers in men, and between 57 and 86% of lung cancers in women, are attributable to cigarette smoking. For both sexes combined, the proportion of cancers arising in the oesophagus, larynx and oral cavity attributable to the effect of tobacco, either acting singly or jointly with the consumption of alcohol, is between 43 and 60%. A large proportion of cancers of the bladder and pancreas and a small proportion of cancers of the kidney, stomach, cervix and nose, and myeloid leukaemia are also causally related to tobacco consumption. Because of the length of the latency period, tobacco-related cancers observed today are related to the cigarette smoking patterns over several previous decades. On stopping smoking, the increase in risk of cancer induced by smoking rapidly ceases. Benefit is evident within 5 years and is progressively more marked with the passage of time.
Smoking also causes many other diseases, most notably chronic obstruction pulmonary disease (commonly called chronic bronchitis) and an increased risk of both heart disease and stroke. The death rate of long-term cigarette smokers in middle age (35–69 years of age) is three times that of life-long non-smokers; and approximately half of regular cigarette smokers, who started smoking early in life, eventually die because of their habit. Half the deaths take place in middle age, when the smokers lose 20–25 years of life expectancy compared to non-smokers; the rest occur later in life when the loss of expectation of life is 7–8 years. There is, however, now clear evidence that stopping smoking before cancer or some other serious disease develops avoids most of the later risk of death from tobacco, even if cessation of smoking occurs in middle age (Table 7). While the rate at which young people start to smoke will be a major determinant of ill-health and mortality in the second half of this century, it is the extent to which current smokers give up the habit that will determine the mortality in the next few decades and which requires the urgent attention of public health authorities throughout Europe.
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Tobacco smoke released into the environment by smokers, commonly referred to as environmental tobacco smoke (ETS) and which may be said to give rise to enforced ‘passive smoking’, has several deleterious effects on people who inhale it. It causes a small increase in the risk of lung cancer and also some increase in the risk of heart disease and respiratory disease, and is particularly harmful to small children. Smoking during pregnancy increases the risk of stillbirth, diminishes the infant’s birth weight and impairs the child’s subsequent mental and physical development, while smoking by either parent after the child’s birth increases the child’s risk of respiratory tract infection, severe asthma and sudden death.
Although the greatest hazard is caused by cigarette smoking, cigars can cause similar hazards if their smoke is inhaled, and both cigar and pipe smoking cause comparable hazards of cancers of the oral cavity, pharynx, extrinsic larynx and oesophagus. There is strong scientific evidence that smokeless tobacco, whether sucked, chewed or inhaled, is also associated with an increased risk of cancer.
Worldwide, it is estimated that smoking killed four million people each year in the 1990s, and that altogether some 60 million deaths were caused by tobacco in the second half of the twentieth century. In most countries, the worst consequences of the ‘tobacco epidemic’ are yet to emerge, particularly among women in developed countries and in the populations of developing countries, as, by the time the young smokers of today reach middle or old age, there will be 10 million deaths each year from tobacco (three million in the developed, seven million in the developing countries). If the current prevalence of smoking persists, 500 million of the world’s population today can expect to be killed by tobacco, 250 million in middle age.
The situation in Europe is particularly worrying. The European Union is the second largest producer of cigarettes (749 billion in 1997/98) after China (1675 billion in 1998) and the major exporter of cigarettes (400 billion). In Central and Eastern Europe, there has been a major increase in the smoking habit. Of the six World Health Organization (WHO) regions, Europe has the highest per capita consumption of manufactured cigarettes and faces an immediate and major challenge in meeting the WHO target for a minimum of 80% of the population to be non-smoking. In 1990–1994, 34% of men and 24% of women in the European Union were regular smokers. In women, the rates were reduced by the low rates in southern Europe, but the rates there are rising and seem set to continue to rise over the next decade. In the age range 25–39 years, the rates are higher (55% in men and 40% in women) and this can be expected to have a profound influence on the future incidence of disease. It is particularly disturbing that in many parts of Europe, the prevalence of smoking remains high among general practitioners, who should set an exemplary lifestyle in terms of health. This should be a target for immediate action.
It has been shown that changes in cigarette consumption are affected mainly at a sociological level rather than by actions targeted at individuals (for example, individual smoking cessation programmes). Actions such as advertising bans and increases in the price of cigarettes influence cigarette sales particularly among the young. A ‘tobacco policy’ is consequently essential to reduce the adverse health effects of tobacco, and experience shows that this should be aimed at both stopping young people from starting to smoke and helping smokers to stop. To be efficient and successful, a tobacco policy has to be comprehensive and maintained over a long time period. Increased taxes on tobacco, total bans on direct and indirect advertising, smoke-free enclosed public areas, prominent health warning labels on tobacco products, a policy of low maximum tar levels in cigarettes, education about the effects of smoking, encouragement of smoking cessation, and health interventions at the individual level, all need to be implemented. It must be recognised that nicotine is an addictive drug and that some smokers who are heavily addicted need medical help to overcome the addiction.
The importance of adequate intervention is shown by the low lung cancer rates in those Nordic countries which, since the early 1970s, have adopted integrated central and local policies and programmes against smoking. In the UK, tobacco consumption has declined by 46% since 1970 and lung cancer mortality among men has been decreasing since 1980, although the rate still remains high. In France, between 1993 and 1998, there has been a 11% reduction in tobacco consumption due to the implementation of antitobacco measures introduced by the Loi Evin.
The first point of the European Code Against Cancer is consequently:
Do not smoke. Smoking is the largest single cause of premature death.
If you smoke, stop doing so. In terms of health improvement, stopping smoking before having cancer or some other serious disease avoids most of the later excess risk of death from tobacco even if smoking is stopped in middle age.
If you fail to stop, do not smoke in the presence of non-smokers. The health consequences of your smoking may affect the health of those around you.
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2. Avoid obesity. |
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TopIntroductionMany aspects of general...1. Do not smoke; if...2. Avoid obesity.3. Undertake some brisk,...4. Increase your daily...5. If you drink alcohol,...6. Care must be taken...7. Apply strictly...There are public health...8. Women from 25 years...9. Women from 50 years...10. Men and women from...11. Participate in...Additional items consideredGeneticsCancer mortality trendsFuture directionsSuggested readingReferences |
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3. Undertake some brisk, physical activity every day. |
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TopIntroductionMany aspects of general...1. Do not smoke; if...2. Avoid obesity.3. Undertake some brisk,...4. Increase your daily...5. If you drink alcohol,...6. Care must be taken...7. Apply strictly...There are public health...8. Women from 25 years...9. Women from 50 years...10. Men and women from...11. Participate in...Additional items consideredGeneticsCancer mortality trendsFuture directionsSuggested readingReferences |
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In this section, the adverse effect of obesity (or being overweight) and the protective effect of physical activity on cancer risk are summarised. It is based on the evidence from a comprehensive review on weight control and physical activity published by the International Agency for Research on Cancer (IARC). Because of the relationship between obesity and physical activity it is important to separate the effects of the two.
Obesity
Obesity is an established major cause of morbidity and mortality. It is the largest risk factor for chronic disease in western countries after smoking, particularly increasing the risk of diabetes, cardiovascular disease and cancer. Most countries in Europe have seen the prevalence of obesity [defined as a body mass index (BMI) of 
30 kg/m2; Figure 1] rapidly increase over the years. The prevalence ranges from <10% in France to 20% in the UK and Germany and higher in some central European countries (>30%). It is associated with an increased risk of cancer at several sites and the evidence is clear for cancer of the colon, breast (postmenopausal), endometrium, kidney and oesophagus (adenocarcinoma). There is still an excess risk after allowing for several factors, such as physical activity. Overweight (BMI of 25–29 kg/m2) is similarly associated with these cancers though the effect on risk is less.
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The risk of colon cancer increases approximately linearly with increasing BMI between 23 and 30 kg/m2. Compared with having a BMI <23 kg/m2 the risk increases
50–100% in people with a BMI 30 kg/m2. The association appears to be greater in men than in women. For example, in the American Cancer Society cohort study of 1.2 million people, the increase in risk of colon cancer in those with a BMI 30 kg/m2 was 75% in men and 25% in women compared to those with a BMI <25 kg/m2. The evidence also suggests that the risk does not depend on whether the person had been overweight in early adulthood or later in life.
Over 100 studies have consistently shown a modest increased risk of breast cancer in postmenopausal women with a high body weight. On average, epidemiological studies have shown an increase in breast cancer risk above a BMI of 24 kg/m2. A pooled analysis of eight cohort studies of 340 000 women showed an increase in risk of 30% in women with a BMI 28 kg/m2 compared to those with a BMI of <21 kg/m2. Factors that have been shown to attenuate the association between obesity and breast cancer include family history (heavier women with a family history of breast cancer have a higher risk than similar women without a family history) and the use of hormone replacement therapy (HRT) (the risk of breast cancer associated with obesity is greater in women who had never used HRT). In contrast, among premenopausal women obesity is not associated with an increase in risk of breast cancer.
There is consistent evidence that being overweight is associated with an increased risk of endometrial cancer. Women with a BMI of >25 kg/m2 have a two- to three-fold increase in risk. Although limited, the evidence suggests that the risk is similar in pre- and postmenopausal women. There is evidence that the risk is greater for upper-body obesity.
The association between kidney (renal cell) cancer and BMI is also well established and is independent of blood pressure. Individuals with a BMI of 30 kg/m2 have a two- to three-fold increase in risk compared with those below 25 kg/m2. The effect is similar in men and women. There is a similarly strong association between being overweight and adenocarcinoma of the lower oesophagus and the gastric cardia; about two-fold increase in risk in individuals with a BMI of >25 kg/m2. A modest association has been reported in a pooled analysis of BMI and thyroid cancer (the increase in risk in those in the highest third of BMI was 20% in women and 50% in men). The evidence on obesity and gallbladder cancer is limited but there is a suggestion of almost a two-fold increase in risk, especially in women.
In Western Europe, it has been estimated that being overweight or obese accounts for 11% of all colon cancers, 9% of breast cancers, 39% of endometrial cancers, 37% of oesophageal adenocarcinomas, 25% of renal cell cancer and 24% of gallbladder cancer.
Physical activity
Many studies have examined the relationship between physical activity and the risk of developing cancer. There is consistent evidence that some form of regular physical activity is associated with a reduction in the risk of colon cancer. There is also a suggestion of a risk reduction in relation to cancer of the breast, endometrium and prostate. The protective effect of physical activity on cancer risk improves with increasing levels of activity (the more the better) though such a recommendation should be moderated in individuals with cardiovascular disease. Regular physical activity that involves some exertion may be needed to maintain a healthy body weight, particularly for people with sedentary lifestyles. This could involve half an hour per day three times per week. More vigorous activity several times per week may give some additional benefits regarding cancer prevention.
For some cancers, the preventive effect of regular physical activity seems to act independently of weight control. The prevention of weight gain and obesity and the promotion of exercise should ideally begin early in life. However, the benefits can also be gained later in life if a healthy lifestyle is adopted. It is desirable to maintain a BMI in the range of 18.5–25 kg/m2, and people who are already overweight or obese should aim to reduce their BMI to <25 kg/m2. A lifestyle that incorporates a healthy diet, exercise and weight control is beneficial to the individual not only with regards to cancer but also other diseases.
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4. Increase your daily intake and variety of vegetables and fruits: eat at least five servings daily. Limit your intake of foods containing fats from animal sources. |
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TopIntroductionMany aspects of general...1. Do not smoke; if...2. Avoid obesity.3. Undertake some brisk,...4. Increase your daily...5. If you drink alcohol,...6. Care must be taken...7. Apply strictly...There are public health...8. Women from 25 years...9. Women from 50 years...10. Men and women from...11. Participate in...Additional items consideredGeneticsCancer mortality trendsFuture directionsSuggested readingReferences |
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Diet and nutritional factors started to be the focus of serious attention in the aetiology of cancer from the 1940s onwards. Originally dealing with the effect of feeding specific diets to animals receiving chemical carcinogens, research turned to the potential of associations with human cancer risk. Initially, this was conducted through international comparisons of estimated national per capita food intake data with cancer mortality rates. It was consistently found that there were very strong correlations in these data, particularly with dietary fat intake and breast cancer. As dietary assessment methods became better, and certain methodological difficulties were identified and overcome, the science of Nutritional Epidemiology emerged.
Doll and Peto estimated that somewhere between 10 and 70% of all cancer deaths were associated with dietary and nutritional practices, with the best estimate 30%. In 1983, the United States Academy of Science concluded that, after tobacco smoking, diet and nutrition was the single most important cause of cancer. Since then, the epidemiological search has been to improve knowledge of the exact relationships between food and nutrition and cancer risk and to identify associations with particular components of diet and determine the best intervention strategy.
Initially, much attention focused on intake of fat in the diet, particularly from animal sources. Although the results from ecological studies and data from animal experiments were very strong regarding this association, findings from retrospective and prospective epidemiological studies have been inconsistent, particularly regarding the association with breast cancer and colorectal cancers.
A number of epidemiological studies indicate a protective effect of higher intakes of vegetables and fruit on the risk of a wide variety of cancers, in particular oesophagus, stomach, colon, rectum and pancreas. A higher consumption of vegetables and fruits has been associated with a reduced risk of cancer at various sites in several studies from Europe, mostly using a case–control design. The relation is however less consistent in data from several cohort studies from North America. If any, the association was apparently most marked for epithelial cancers, in particular those of the alimentary and respiratory tract, although such an association is weak to non-existent for hormone-related cancers.
Cereals with high fibre content and whole-grain cereals have been associated with lower risk of colorectal cancer and other digestive tract tumours in a few European studies. However, several large cohort and randomised intervention studies have not supported this association. The EPIC (European Prospective Investigation into Cancer and Nutrition) study, examined this association in 519 978 individuals aged 25–70 years, recruited from 10 European countries. Follow-up consisted of 1 939 011 person-years, and data for 1065 reported cases of colorectal cancer were included in the analysis. Dietary fibre in foods was inversely related to incidence of large bowel cancer {adjusted relative risk 0.75 [95% confidence interval (CI) 0.59–0.95] for the highest versus lowest quintile of intake}, the protective effect being greatest for the left side of the colon, and least for the rectum. After calibration with more detailed dietary data, the adjusted relative risk for the highest versus lowest quintile of fibre from food intake was 0.58 (95% CI 0.41–0.85). No food source of fibre was significantly more protective than others, and non-food supplement sources of fibre were not investigated. The authors concluded that in populations with low average intake of dietary fibre, an approximate doubling of total fibre intake from foods could reduce the risk of colorectal cancer by 40%.
The confusing nature of this association between fibre intake and colorectal cancer risk is highlighted by the simultaneous publication of two studies, one of which confirmed this finding and another which reported no association.
Lower rates of many forms of cancer reported in southern European regions, like in Southern Europe, have been attributed to a diet lower in meats and fats from animal sources, and higher in fish, olive oil, vegetables and fruits, grains and moderate alcohol consumption. While a link has been suggested, this has not yet been proved convincingly.
The association with reduced risk of cancer exists for a wide variety of vegetables and fruits. There also exists increasing evidence that consumption of higher levels is also beneficial for other chronic diseases. Vegetables and fruits contain a large number of potentially anticarcinogenic agents, with complementary and overlapping mechanisms of action. However, the exact molecule(s) in vegetables and fruits that confers this protection is unknown. Insight into the mechanisms of action is only incomplete, but this is not required for public health recommendations. It is, in any case, not possible to recommend dietary supplementation with vitamins and minerals to reduce cancer risk based on the evidence currently available.
Nonetheless, it is difficult to be precise about the advisable quantity of fruits and vegetables and it is difficult to imagine the successful implementation of a randomised trial of increased consumption of fruits and vegetables. The best available evidence comes from observational studies and the search continues for the molecule(s) in fruits and vegetables responsible for the apparent protection.
Fruits and vegetables should be taken with each meal whenever possible, and systematically replace snacks between meals. In line with WHO and USA recommendations, ‘five-a-day’ (minimum 400 g/day, i.e. two pieces of fruit and 200 g of vegetables) is advocated, which could lead to a reduction in cancer risk. Particular attention regarding changing nutritional practices needs to be paid to the countries of central and Eastern Europe, where rapid changes in dietary patterns have been shown to have had a rapid positive influence on death rates from chronic disease.
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5. If you drink alcohol, whether beer, wine or spirits, moderate your consumption to two drinks per day if you are a man or one drink per day if you are a woman. |
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TopIntroductionMany aspects of general...1. Do not smoke; if...2. Avoid obesity.3. Undertake some brisk,...4. Increase your daily...5. If you drink alcohol,...6. Care must be taken...7. Apply strictly...There are public health...8. Women from 25 years...9. Women from 50 years...10. Men and women from...11. Participate in...Additional items consideredGeneticsCancer mortality trendsFuture directionsSuggested readingReferences |
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There is wide variability among European Union countries in terms of per capita average alcohol consumption and preferred type of alcoholic beverage (Figure 2). Although three groups of countries are traditionally identified according to the prevalent drinking culture (wine drinking in the South, beer drinking in the Central Europe and spirit drinking in the North), there is considerable variability within such groups and within countries, and new patterns are evolving rapidly (e.g. increasing consumption of wine in northern countries; increasing prevalence of binge drinking, in particular among women).
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There is convincing epidemiological evidence that the consumption of alcoholic beverages increases the risk of cancers of the oral cavity, pharynx and larynx and of squamous cell carcinoma of the oesophagus. The risks tend to increase with the amount of ethanol drunk, in the absence of any clearly defined threshold below which no effect is evident.
Although alcohol drinking increases the risk of upper digestive and respiratory tract neoplasms, even in the absence of smoking, alcohol drinking and tobacco smoking together greatly increase the risk of these cancers, each factor approximately multiplying the effect of the other. Compared to never-smokers and non-alcohol drinkers, the relative risk of these neoplasms is increased between 10- and 100-fold in people who drink and smoke heavily (Figure 3). Indeed, in the case of total abstinence from drinking and smoking, the risk of oral, pharyngeal, laryngeal and squamous cell oesophageal cancers in European countries would have been extremely low.
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A likely carcinogenic mechanism of alcohol is by facilitating the carcinogenic effect of tobacco and possibly of other carcinogens to which the upper digestive and respiratory tract are exposed, particularly those of dietary origin. However, a direct carcinogenic effect of acetaldehyde, the main metabolite of ethanol, and of other agents present in alcoholic beverages cannot be excluded. A diet poor in fruits and vegetables, typical of heavy drinkers, is also likely to play an important role. There does not seem to be a different effect of beer, wine or spirits on cancer risk at these sites; rather the total amount of ethanol ingested appears to be the key factor in determining the increase in risk. Only a few studies have analysed the relationship between stopping alcohol drinking and the risk of cancers of the upper respiratory and digestive tract. There is clear evidence that the risk of oesophageal cancer is reduced by 60% 10 years or more after drinking cessation. The pattern of risk is less clear for oral and laryngeal cancers. Stopping (or reducing) alcohol drinking, particularly in association with smoking cessation, represents a priority for preventing oesophageal cancer.
Alcohol drinking is also strongly associated with the risk of primary liver cancer; the mechanism however might be mainly or solely via the development of liver cirrhosis, implying that light or moderate drinking may have limited influence on liver cancer risk. Moreover, there is some evidence suggesting that heavy alcohol consumption is particularly strongly associated with liver cancer among smokers and among people chronically infected with hepatitis C virus (HCV).
An increased risk of colorectal cancer has been observed in many cohort and case–control studies, which seems to be linearly correlated with the amount of alcohol consumed and independent from the type of beverage.
An increased risk of breast cancer has been consistently reported in epidemiological studies conducted in different populations. Although not strong (increased risk in the order of 10% for each 10 g/day increase in alcohol intake, possibly reaching a plateau at the highest levels of intake), the association is of great importance because of the apparent lack of a threshold, the large number of women drinking a small amount of alcohol and the high incidence of the disease. Indeed, more cases of breast cancer than of any other cancer are attributable to alcohol drinking among European women (Table 8). It has been suggested that alcohol acts on hormonal factors involved in breast carcinogenesis, but the evidence is currently inadequate to identify a specific mechanism.
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Besides increasing cancer risk, alcohol drinking entails complex health consequences, making it difficult to formulate universal public health guidelines. There is strong evidence for a J-shaped pattern of risk of total mortality and cardiovascular disease according to increasing alcohol consumption (Figure 4). This classic pattern is one of decreased risk in light drinkers compared with non-drinkers and then an increasing risk as alcohol consumption increases. In addition, alcohol drinking increases the risk of injuries in many types of motor vehicle, leisure and occupational injuries (e.g. driving, swimming, manual working) and accident mortality rates are influenced by per capita alcohol consumption across Europe. Moreover, drinking alcohol during pregnancy has a detrimental effect on the development of the foetus and its central nervous sytem, often resulting in malformations, behavioural disorders and cognitive deficits in the postnatal period.
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For these reasons, the task of fixing a threshold on daily alcohol intake below which the increased risk of cancer and other diseases is offset by a reduced risk of cardiovascular diseases is not simple. Factors such as age, physiological condition and dietary intake certainly modify any such threshold: in particular, the beneficial effects on cardiovascular diseases appear only at middle age.
In conclusion, there is evidence showing that a daily alcohol intake as low as 10 g/day (that is, approximately, one can of beer, one glass of wine or one shot of spirit) (Figure 5) is associated with some increase in breast cancer risk relative to non-drinkers, while the intake associated with a significant risk of cancer at other sites (such as cancers of the upper digestive and respiratory tracts, liver or colorectum) is probably somewhat higher (20–30 g/day).
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All the above points should be considered to give sensible advice regarding individual recommended limits of alcohol consumption. The limit should not exceed between 20 g of ethanol per day (i.e. approximately two drinks of either beer, wine or spirit each day) and it should be as low as 10 g per day for women.
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6. Care must be taken to avoid excessive sun exposure. It is specifically important to protect children and adolescents. For individuals who have a tendency to burn in the sun active protective measures must be taken throughout life. |
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TopIntroductionMany aspects of general...1. Do not smoke; if...2. Avoid obesity.3. Undertake some brisk,...4. Increase your daily...5. If you drink alcohol,...6. Care must be taken...7. Apply strictly...There are public health...8. Women from 25 years...9. Women from 50 years...10. Men and women from...11. Participate in...Additional items consideredGeneticsCancer mortality trendsFuture directionsSuggested readingReferences |
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Skin cancer is predominantly, but not exclusively, a disease of white skinned people. Its incidence, furthermore, is greatest where fair skinned peoples live at increased exposure to ultraviolet (UV) light, such as in Australia. Figure 6 shows the marked latitudinal gradient in age-related incidence of melanoma, the form of skin cancer most likely to metastasise and cause death. The main environmental cause of skin cancers is sun exposure, and UV light is deemed to represent the component of the solar spectrum involved in skin cancer occurrence.
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The type of sun exposure which causes skin cancer however appears to differ in the three main types. Squamous cell carcinoma shows the clearest relationship with cumulative sun exposure. This form of skin cancer is therefore most common in outdoor workers. The recipients of transplanted organs are particularly at risk of these tumours as a result of the combined effects of the unchecked growth of human papilloma virus (HPV) in their skin due to immunosuppression, and exposure to the sun. Basal cell carcinoma is the commonest type of skin cancer but it is the least serious as it is a local disease only. This form of skin cancer appears to share an aetiological relationship to sun exposure with melanoma.
The risk of cutaneous melanoma appears to be related to intermittent sun exposure. Examples of intermittent sun exposure are sunbathing activities and outdoor sport activities. Also, a history of sunburn has repeatedly been described as a risk factor for melanoma, which again is associated with intermittent sun exposure.
The incidence of melanoma has doubled in Europe between the 1960s and the 1990s and this is attributed to increased intense sun exposure, which has taken place this century. The incidence of squamous cell and of basal cell cancers has also increased in all European countries. Although much less life threatening than melanoma, these tumours represent 95% of all skin cancers, and their treatment amount to considerable costs for individuals and social security systems.
The advice to the European population must therefore be to moderate sun exposure: to reduce their total life-time exposure, and in particular to avoid extremes of sun exposure and sunburn. All Europeans however are not equally susceptible to skin cancer. The fairest are more susceptible, particularly those with red hair (but not exclusively), freckles and a tendency to burn in the sun.
The strongest phenotypic risk factor for melanoma however is the presence of large numbers of moles or melanocytic naevi, and twin study evidence is strong that the major determinant of naevus number is genetic with an added contribution from sun exposure. These naevi may be normal in appearance but are also usually accompanied by so-called atypical moles: moles which are larger than 5 mm in diameter with variable colour within and an irregular shape. The phenotype is described as atypical mole syndrome (AMS). The AMS is present in something like 2% of the north European population and is associated with an approximately ten times increased risk of melanoma. Advice about sun protection is therefore particularly of importance to this sector of the population. Some patients with the AMS report a family history, and overall a strong (three or more cases) family history is the greatest predictor of risk. These families should avoid the sun and should be referred to dermatologists for counselling.
The best protection from the summer sun is to stay out of it, but the following advice is given in order to allow safer enjoyment of the outdoors. Keeping out of the sun between 11 am and 3 pm is effective as UV exposure is greatest at this time. Therefore, scheduling outdoor activities for other times is important, particularly for children. Using shade is allied to this and clothing remains the second most important measure. Close weave heavy cotton affords good protection although the clothing industry is increasingly developing UV protective clothes with high sun protection properties, which are very valuable particularly where it is difficult to keep out of the sun.
Sunscreens are useful for protection against sunburns of skin sites such as the face and the ears. Sunscreen may protect against squamous cell carcinoma but there is currently inadequate evidence for their preventive effect against basal cell carcinoma and melanoma. However it is extremely important when using sunscreen to avoid prolongation of the duration of sun exposure that may be responsible for an increased risk of melanoma. Additionally, there is evidence that using higher SPF sunscreen prolongs further time spent in the sun. Great care should be taken when choosing to use sunscreen and also in the choice of SPF. In addition, sunbed use is also discouraged, as exposure to these devices resembles the type of sun exposure mostly associated with melanoma occurrence.
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7. Apply strictly regulations aimed at preventing any exposure to known cancer-causing substances. Follow all health and safety instructions on substances which may cause cancer. Follow advice of national radiation protection offices. |
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TopIntroductionMany aspects of general...1. Do not smoke; if...2. Avoid obesity.3. Undertake some brisk,...4. Increase your daily...5. If you drink alcohol,...6. Care must be taken...7. Apply strictly...There are public health...8. Women from 25 years...9. Women from 50 years...10. Men and women from...11. Participate in...Additional items consideredGeneticsCancer mortality trendsFuture directionsSuggested readingReferences |
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The prevention of exposure to occupational and environmental carcinogens has followed the identification of a substantial number of natural and man-made carcinogens, and has led to significant reductions in cancer occurrence. The message in this item of the code solicits responsible behaviour for individuals in three respects: (i) from those who have to provide timely and clear instructions, primarily legislators and regulators who should adapt scientific consensus evaluations into European Union law, and control compliance with these regulations; (ii) from those who should follow these instructions and comply with the laws to protect the health of others, for instance, managers, hygienists and doctors in industry; and (iii) from every citizen who in order to protect their own health and the health of others, ought to pay heed to the presence of carcinogenic pollutants and follow instructions and regulations aimed at mitigating or preventing exposure to carcinogens. The latter applies to a wide variety of circumstances such as traffic restrictions within cities, restrictions on smoking, use of personal safety devices and respecting validated procedures in the workplace. Application of regulations is particularly important in the working environment where carcinogens may be found in higher concentrations than in the general environment. The control of the prevalence and level of exposure to occupational and environmental carcinogens through general preventive measures has historically played a more important role in preventing cancers than individual measures of protection.
The cancers that have most frequently been associated with occupational exposures are those of the lung, urinary bladder, mesothelioma, larynx, leukaemia, angiosarcoma of the liver, nose and nasal cavity and skin (non-melanoma). Several other neoplasms have also been associated with occupational exposures but the evidence is less strong. They include cancers of the oral cavity, nasopharynx, oesophagus, stomach, colon and rectum, pancreas, breast, testis, kidney, prostate, brain, bones, soft-tissue sarcoma, lymphomas and multiple myeloma. Most known or suspected occu