There are Public Health programmes which could prevent cancers developing or increase the probability that a cancer may be cured. Early detection is an important factor in reducing the death rate from cancer, whether it is achieved by personal actions or through participation in organised public health programmes. Awareness of different visual body signs or symptoms that could easily be observed by anyone and that are possibly related to cancer is important. It is unequivocally established that cancer survival is better for early, localised disease than for the later stage, advanced forms of the disease. Thus, the earlier in the process that a cancer can be diagnosed and treated then the better this is for the patient. Potential symptoms of cancer should not be ignored, but should serve as a clear warning for the individual to consult his or her doctor for advice. The signs and symptoms described in Table 10 are not specific for cancer. When any one is present, the individual should see a doctor. Much effort has gone into cancer screening and the development of methods for finding cancers at an earlier stage in their development and increasing the prospects of a cure. It is possible to make recommendations based on the available evidence.

:: Men and women from 50 years of age should participate in colorectal screening. This should be within programmes with built-in quality assurance proceduresThe identification of a well-determined pre-malignant lesion, the adenomatous polyp, together with the good survival associated with early disease, make colorectal cancer an ideal candidate for screening. In the past quarter century, progress has been made in our ability to screen patients for colorectal cancer or its precursor state, using advances in imaging and diagnostic technology. Faecal occult blood guaiac test cards were first employed in the 1960s, the flexible sigmoidoscope was introduced in the mid-1970s to replace the rigid sigmoidoscope which had been first introduced in 1870, and colonoscopy has been available since 1970.

Four randomised trials have examined annual or biennial screening with Faecal Occult Blood Testing (FOBT) while there are only data available regarding sigmoidoscopy and colonoscopy from observational studies, and little yet from randomised trials. There is evidence from these randomised trials to support the use of FOBT with a reduction in colorectal cancer mortality of about 16% (95% Confidence Interval = 9% to 22%) from a meta-analysis [27% (95% CI =10% to 43%) reduction among those screened]. The proposed screening interval is 2 years, though it has been judged that yearly examinations are cost-effective.

Flexible sigmoidoscopy is an alternative or complementary method of screening. The higher sensitivity of colonoscopy over FOBT suggests that colonoscopy is more effective. A large randomised trial is underway which should have results in 2005 or 2006.

Despite the evidence showing that screening is worthwhile most citizens of developed countries have not been screened for colorectal cancer by any means. While this situation persists the chance is being missed to prevent about one quarter of the 138.000 colorectal cancer deaths which occur each year in the European Union.

There are Public Health programmes which could prevent cancers developing or increase the probability that a cancer may be cured Early detection is an important factor in reducing the death rate from cancer, whether it is achieved by personal actions or through participation in organised public health programmes. Awareness of different visual body signs or symptoms that could easily be observed by anyone and that are possibly related to cancer is important. It is unequivocally established that cancer survival is better for early, localised disease than for the later stage, advanced forms of the disease. Thus, the earlier in the process that a cancer can be diagnosed and treated then the better this is for the patient. Potential symptoms of cancer should not be ignored, but should serve as a clear warning for the individual to consult his or her doctor for advice. The signs and symptoms described in Table 10 are not specific for cancer. When any one is present, the individual should see a doctor. Much effort has gone into cancer screening and the development of methods for finding cancers at an earlier stage in their development and increasing the prospects of a cure. It is possible to make recommendations based on the available evidence.

:: Women from 50 years of age should participate in breast screening. This should be within programmes with quality control procedures in compliance with European Union Guidelines for Quality Assurance in Mammography Screening.

Mammography can detect breast tumours at a clinically undetectable stage. The results of the early randomised trials of mammographic screening demonstrated the value of this technique and led to the introduction of organised national programmes of screening in several countries in 1986–8. Reports from seven trials involving over half a million women subsequently indicated a reduction in mortality from breast cancer of about 25% in women invited to be screened. The reduction of mortality in those actually attending screening is about one third.

There is now considerable evidence that breast cancer screening with mammography is effective in reducing mortality from breast cancer. An overview of the Swedish trials reported relative risks of death of 0.71 in the group randomised to receive an offer of screening, with 95% confidence internal 0.57–0.89 for women aged 50–59 years at entry. Results for women ages 60–69 were almost identical. When applied to a population, a well-organised programme with a good compliance should lead to a reduction in breast cancer mortality of at least 20% in women aged over 50.

The value of screening women aged under 50 years is uncertain. No trials have had large enough statistical power to analyse these women separately. What recommendations should be made for mammographic screening of women aged between 40 and 49 is an important question that cannot currently be answered; over 40% of the years of life lost due to breast cancer diagnosed before the age of 80 years are attributable to cases presenting symptomatically at ages 35–49 years, frequently an age of considerable social responsibility.

Swedish workers have recently conducted an overview of four of their trials. The conclusions indicate that the benefit of breast screening, in terms of a reduction in breast cancer mortality of 21%, persisted for a median time of 15.8 years. In addition to this overview, two working groups have been convened. A working group of the International Agency for Cancer Research (IARC) met in Lyon on 5–12 March 2002 and consisted of 24 experts from 11 countries. The quality of the seven trials was assessed and it was concluded that screening by mammography reduced mortality from breast cancer in women of 50–69 years of age. In women who participated in screening programmes this reduction was estimated at 35%. For women of 40–49 years, evidence for a reduction in mortality was too limited to reach a conclusion. The evidence is insufficient to recommend performing routine breast self-examination as a method of screening.

Forty years of clinical trials, the contribution of hundreds of scientists and health workers and the dedication of hundreds of thousands of women to participate in studies lasting for decades has resulted in adequate evidence to support the efficacy of mammographic screening for breast cancer, which now allows its transfer to the arena of public health care . Doctors and women should be assured that participation in organised screening programmes with high quality control standards is of benefit, provided appropriate investigation and treatment is available. European Guidelines for Quality Control in Mammographic Screening have been developed and are widely employed throughout Europe.

Special efforts should be made to encourage screening among the more deprived members of communities. It is important not to over-emphasise the benefit of screening, and to appreciate that mammographic screening is but one step in the total care of women with the disease. As had been shown by long-term established programmes in the UK, Sweden, Finland and The Netherlands recognition of the importance of the multidisciplinary team in the assessment of mammographic abnormalities spread into the symptomatic sector leading to the development of integrated multidisciplinary breast care centres. Staffed by dedicated surgeons, radiologists and pathologists working alongside breast care nurses, counselling and other support personnel, these centres offer the necessary care for women with breast cancer.

 There are Public Health programmes which could prevent cancers developing or increase the probability that a cancer may be cured Early detection is an important factor in reducing the death rate from cancer, whether it is achieved by personal actions or through participation in organised public health programmes. Awareness of different visual body signs or symptoms that could easily be observed by anyone and that are possibly related to cancer is important. It is unequivocally established that cancer survival is better for early, localised disease than for the later stage, advanced forms of the disease. Thus, the earlier in the process that a cancer can be diagnosed and treated then the better this is for the patient. Potential symptoms of cancer should not be ignored, but should serve as a clear warning for the individual to consult his or her doctor for advice. The signs and symptoms described in Table 10 are not specific for cancer. When any one is present, the individual should see a doctor. Much effort has gone into cancer screening and the development of methods for finding cancers at an earlier stage in their development and increasing the prospects of a cure. It is possible to make recommendations based on the available evidence.

:: Women from 25 years of age should participate in cervical screening. This should be within programmes with quality control procedures in compliance with European Guidelines for Quality Assurance in Cervical Screening.

In many developing countries, the uterine cervix is one of the most prevalent sites for cancer, comprising about 25% of all female cancers. In industrialised populations, the disease is less common. In eastern and central European populations, the annual age-adjusted (using the World Standard Population as reference) incidence rates for invasive disease are 15–25 per 100.000 women. In the Nordic countries, the annual incidence was 15–30 per 100.000 women before the start of large-scale mass screening programmes.

The effectiveness of screening for cervical cancer has never been demonstrated in a randomised trial. There is, however, sufficient non-experimental evidence showing the efficacy of screening using a cervical smear (Pap) test performed every 3–5 years. This is based on case–control and cohort studies and on time trends and geographical differences associated within screening. The largest of these is the collaborative study co-ordinated by the International Agency for Research on Cancer (IARC) which showed that eradication of the disease is an unrealistic goal and that maximal protection after a negative smear is about 90%, which remains roughly the same during several years after the test. This conclusion is in agreement with the results of studies on the natural history of the disease, which have shown that most preinvasive lesions progress to frankly invasive cancer only over several years.

The effects are somewhat smaller at a population level. In some of the Nordic countries, the reduction was about 80% in women in the age groups exposed most intensively to screening. In the mid-1980s, after several years of organised screening, the overall incidence was 5–15 per 100.000 woman-years.

Cervix cancer screening should be offered to all women over 25 years. There is limited evidence of benefit from screening in women aged over 60 years, though the likely yield of screening is low in women over age 60 since the incidence of high-grade cervical lesions declines after middle age. Screening this age group is associated with potential harms from false-positive results and subsequent invasive procedures. Stopping screening in older women is probably appropriate among women who have had three or more consecutive previous (recent) normal Pap smear results. Yield is also low after hysterectomy, which leaves some cervical tissue, and there is scant evidence to suggest that screening produces improved health outcomes.

An organised programme consists of several essential elements. Defining the population to be screened is important. Personal invitation is the single most important means of attaining high attendance, especially when it is combined with effective information through the mass media. Free service has also been shown to improve attendance. Quality assurance of all steps of the process, monitoring and constant evaluation of the proportion of cancer detected, false positives and false negative readings, are mandatory. Near maximal effectiveness is achieved by an organised programme with high coverage, in which screening is initiated at the age of 25 years and is repeated at three- or five-year intervals until the age of 60. Extension of this approach should be considered only if maximal coverage has been attained, the resources are available and the marginal cost-effectiveness of the recommended changes has been evaluated.European Guidelines for Quality Control in Cervix Cancer Screening have been developed and are widely followed in Europe.

Infection with certain strains of HPV, generally acquired sexually, is the most important risk factor for cervical cancer. With the use of (modern) HPV detection methods over 90% of squamous cell cervical cancer and 75–85% of high-grade cervical intraepithelial neoplasia (CIN) lesions have detectable HPV DNA. Given the implication of HPV infection in cervical cancer, detecting HPV could represent an appealing screening method. A study of 2009 women having routine screening in England and Wales, showed that 44% of CIN lesions of grade 2/3 detected had negative cytology and were found only by HPV testing (for types 16, 18, 31 and 33): a further 22% were positive for HPV but demonstrated only borderline or mild cytological changes. However, 25% of CIN grade 2/3 lesions were not detected by the four HPV tests.

Routine HPV testing for cervical cancer screening is an important research topic at present as HPV infection is very common in women less than 30 years old, and what matters are those women over the age of 30 with a HPV infection that persists over a long period of time. HPV testing is still to be evaluated to find the role it could play in cervical cancer screening. It has the potential to become an important test in detecting cervix lesions in future and should be a current research priority.

Many aspects of general health can be improved, and certain cancers avoided, if you adopt a healthier lifestyle.

:: 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.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. Figure6 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.

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.

Many aspects of general health can be improved, and certain cancers avoided, if you adopt a healthier lifestyle

:: If you drink alcohol, whether beer, wine or spirits, moderate your consumption to two drinks per day if you are a man and one drink per day if you are a womanThere is wide variability among European Union countries in terms of per capita average alcoholconsumption and preferred type of alcoholic beverage figure2. 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).

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 figure3. 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.

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 table8. 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.

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 figure4. 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.

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) figure5 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 (approximately 20–30 g/day).

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.

Many aspects of general health can be improved, and certain cancers avoided, if you adopt a healthier lifestyle.

:: Undertake some brisk, physical activity every day

In this section, the adverse effect of obesity (or being overweight) and the protective effect of exercise 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. Because of the relationship between obesity and physical activity it is important to separate the effects of the two.

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 ideally should 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 to 25 kg/m2 and people who are already overweight or obese should aim to reduce their BMI to below 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.

Many aspects of general health can be improved, and certain cancers avoided, if you adopt a healthier lifestyle

:: Eat a variety of vegetables and fruits every day: eat at least five portions daily. Limit your intake of foods containing fats from animal sources

Diet and nutritional factors commenced to be the focus of serious attention in the aetiology of cancer from the 1940s onwards. Initially 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 around 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 null particularly regarding the association with the breast cancer and colorectal cancer.

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 of 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 fiber content and whole-grain cereals have been associated to lower risk of colorectal cancer and other digestive tract in a few European studies. However, recent large cohort and intervention studies are not supporting this 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 fats from animal sources, and meats, 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 which confers this protection is unknown and the exact mechanism of action 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 in between meals. In line with World Health Organisation (WHO) and United States recommendations, ‘Five-a-day’ (minimum 400 gr/day, i.e. 2 pieces of fruit and 200 gr of vegetables) is advocated in this campaign, 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, and positive influence, on death rates from chronic disease.

Many aspects of general health can be improved, and certain cancers avoided, if you adopt a healthier lifestyle

:: Avoid Obesity 

In this section, the adverse effect of obesity (or being overweight) and the protective effect of exercise 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. Because of the relationship between obesity and physical activity it is important to separate the effects of the two.

:: Obesity
Obesity is an established and major cause of morbidity and mortality. It is the largest risk factor for chronic disease in Western countries after smoking, increasing in particular the risk for diabetes, cardiovascular disease and cancer. Most countries in Europe have seen the prevalence of obesity (defined as a body mass index, BMI, of ³30 kg/m2) rapidly increase over the years. The prevalence can range from less than 10% in France to about 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 (post-menopausal), 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 will be less.The risk of colon cancer increases approximately linearly with increasing BMI between 23 and 30 kg/m2. Compared to having a BMI of <23 kg/m2 there is a about a 50-100% increase in risk in people with a BMI ³30 kg/m2. The association appears to be greater in men than in women. For example, in the American Cancer Society cohort study of about 1.2 million people, the mortality ratio for colon cancer in those with a BMI of ³30 kg/m2 was 1.75 in men and 1.25 in women compared to those with a BMI of <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 8 cohort studies of about 340.000 women showed an increase in risk of 30% in women with a BMI ³28 kg/m2 compared to those with a BMI of <21 kg/m. Factors that have been shown to attenuate the association between obesity and breast cancer include family history (heavier women with a family history have a higher risk than similar women without a family history) and the use of hormone replacement therapy (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.

There is consistent evidence that being overweight is associated with increased risk for 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 post-menopausal 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 ³30 kg/m2 have a two to three-fold increase in risk compared to 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 (relative risk in those in the highest tertile of BMI was 1.2 in women and 1.5 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 approximately 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.