The frequency of deaths due to cardiovascu-lar diseases increases markedly with age (Fig. 4.9). Throughout the Region, these dis-eases lead to fewer deaths in children than other major causes. Among males and
fe-Table 4.1: Structure of mortality (percentages of deaths) in the WHO European Region by main causes of death, 1970 and 1988/1989
Table 4.2: Structure of mortality (percentage of deaths) in males of all age groups in the WHO European Region by main causes of death, 1990 Table 4.3: Structure of mortality (percentage of deaths) in females of all age groups in the WHO European Region by main causes of death, 1990
Occurrence of Selected Diseases 105
males aged 15 years and over, the mortality due to cardiovascular diseases was markedly lower in the western countries than in the CCEE or the USSR. Owing to a decreasing trend in the western countries, and an in-crease or at best stabilization of the rates in the other two groups, the difference in
mor-tality increased from nonexistent or small (not exceeding 33 %) at the beginning of the 1970s to 100–150 % in people aged 15–64 years and to 66 % in the oldest age group at the end of the 1980s. An exception from the pattern in the eastern countries was the stable or decreasing mortality in the German
Fig. 4.9: Age-specific mortality from cardiovascular diseases in the WHO European Region, by sex, 1970–1990
Democratic Republic. Within the groups of countries, the highest national rates (in Hun-gary) exceeded the lowest (in the German Democratic Republic) by a factor of 1.3 (in people aged 65 years or over) to 2.8 (in males aged 15–44 years).
The limited data on morbidity reported by some countries confirm that cardiovascular diseases are very common in the Region, and are more frequent in the CCEE than in the western countries [8,12]. The prevalence of these diseases was estimated to be 9–15 % in Finland, the Netherlands, Norway and Sweden, 25 % in Czechoslovakia and 31 % in Romania. Although the definitions and re-porting systems used in various countries are not compatible, these data indicate that a substantial proportion of the adult popu-lation of the Region suffer from cardiovascu-lar disorders.
An important source of information on morbidity from cardiovascular diseases is the WHO project on monitoring of trends and determinants in cardiovascular diseases (MONICA), conducted in defined commu-nities of 27 countries throughout the world and including several European centres. The comparison of trends in mortality, using well standardized criteria, confirms decreases in disease frequency in several western coun-tries of the Region and an increase in eastern centres over the 1980s [13,14].
The main recognized risk factors for car-diovascular diseases, and coronary heart dis-ease in particular, are hypertension, high blood cholesterol and tobacco smoking. Pre-ventive strategies concentrate on these fac-tors [15]. Less clear are the roles of obesity and inadequate physical activity, interrelated factors that may be correlated with one of the three main risk factors. Several other life-style factors may also have a direct or indi-rect impact on the development of cardiovas-cular diseases, such as a diet rich in satu-rated fat (which is associated with a high cholesterol level) or in salt (which is associ-ated with increased blood pressure). Genetic predisposition to these diseases is also con-sidered important [16].
Cancer
The differences in the European Region in mortality from cancer are less dramatic than those seen for cardiovascular diseases and depend on the age group (Fig. 4.10). Among children aged 1–14 years, cancer mortality has declined throughout the Region but, owing to a faster decline in western coun-tries, excess mortality appeared in the other two groups of countries by the late 1970s. By the late 1980s, the rates in the CCEE ex-ceeded those in western countries by 22 %, but mortality was even higher in the USSR.
In the group aged 15–44 years, cancer mor-tality in both sexes increased in the CCEE and declined or stabilized in the western countries. As in the younger age group, this led to a marked difference in rates by the end of the 1980s, from similar levels 20 years ear-lier. This pattern was repeated in the group aged 45–64 years, although in women the differences between the groups of countries remained very small. In this age group, some deviation from the general pattern observed for the western countries was seen in men in France and Italy: an increase in mortality in the early 1980s, with subsequent stabiliz-ation. Data on the USSR were less compre-hensive, but the trend in cancer mortality in the second half of the 1980s was similar to that in the CCEE.
In the group aged 65 years and over, cancer was more frequently diagnosed as a cause of death in western countries than in the CCEE or the USSR. All three groups showed an upward trend, and the differences in rates between them remained the same throughout the 1970s and 1980s. At the end of the 1980s, the mortality rates exceeded the level for the early 1970s by 9–18 %.
The ratio of the highest to the lowest national rates within the groups of countries ranged from 1.5 to 2.3. The greatest differ-ence was found in people aged 65 years and over in the CCEE, resulting from compari-son of high rates in Hungary with low rates in Romania.
Differences in diagnostic and coding prac-tices between and within countries may
Occurrence of Selected Diseases 107
hamper a more detailed analysis of geo-graphical variation in cancer mortality, in-cluding cancer sites [17]. The overall dis-tribution of the most common types of fatal cancer, as reflected in the mortality stat-istics, however, should roughly correspond
to cancer site distribution in the Region’s population. Recent IARC publications [17,18] provide extensive discussion of the spatial and temporal patterns in cancer mor-bidity and mortality.
The types of cancer most commonly
diag-Fig. 4.10: Age-specific mortality from cancer in the WHO European Region, by sex, 1970–1990
nosed as causes of death differ in males and females. Fig. 4.11 illustrates the proportional contributions of the types of cancer that caused over 3 % of all cancer deaths in at least one group of countries. In males, cancer of the trachea, bronchus and lung caused about 30 % of cancer deaths in the Region, but mortality varied markedly be-tween countries and was over twice as high
in countries with the highest rates (Czechos-lovakia, Hungary, the Netherlands and the United Kingdom) than in those with the lo-west rates (Iceland, Portugal and Sweden).
In females, this type of cancer was much less frequent than in males (from 1.4 times less frequent in Iceland to 8.8 times in Spain) but was responsible for a greater proportion of cancer deaths in the western countries than
Fig. 4.11: Proportional mortality due to cancer by type in the WHO European Region, 1989–1990
Occurrence of Selected Diseases 109 in the rest of the Region. The dominating
risk factor for lung cancer is tobacco smok-ing: about 85 % of all cases in males is at-tributable to it [19]. Exposure to high levels of radon gas may be a significant risk factor for lung cancer in areas with uranium-bear-ing rocks, but the risk is greater for smokers than for nonsmokers (see Chapters 12 and 18).
In females, breast cancer was the most common cause of death. The highest mortal-ity rates were registered in Austria, the Fed-eral Republic of Germany, the Netherlands and the United Kingdom, and the lowest in the USSR and Yugoslavia. The factors that determine the incidence of breast cancer are uncertain at present [20]. Several lifestyle factors (having a late first child, giving birth after the age of 35 years, prolonged use of oral contraceptives, increased alcohol intake and post-menopausal body mass increase) have been suggested to be relevant, as well as genetic predisposition. A diet rich in fat is also considered a possible risk factor.
Stomach cancer was a relatively common cause of death in both sexes but its frequency is declining in general. The mortality rates varied markedly, being highest in Portugal and the USSR, and in a group of countries in central and southern Europe. The lowest rates were noted in France, Greece, Iceland and Ireland. A more detailed analysis, con-ducted by IARC for nine countries of the European Community, indicates a distinct subnational pattern of mortality due to stom-ach cancer [17]. Among the factors sus-pected of increasing the risk of stomach cancer is a diet rich in starchy food (such as wheat, potatoes and beans) and smoked, salted and fried foods. The consumption of green vegetables and citrus fruit is thought to decrease the risk. No convincing evidence has been found to incriminate nitrates and nitrites in drinking-water [19].
Cancer of the colon and rectum were fre-quently considered together because of poss-ible difficulties in correct diagnosis and clas-sification. Both types are relatively common causes of death from cancer in both sexes.
More specific data show that the mortality
rates in females were close to those in males for colon cancer, but lower for cancer of the rectum. The mortality in Austria, the Federal Republic of Germany and Hungary was three times that in Greece or Yugoslavia.
Dietary factors seem to influence the risk of colon and rectum as well as stomach cancer.
A high intake of fat is thought to increase the risk, while the consumption of vegetables or fibre may reduce it.
Prostate cancer was one of the most com-mon forms of malignant disease in men, al-though very rare in those aged under 50 years. Mortality rates varied widely between countries, and the proportion of all cancer deaths caused by prostate cancer ranged from 3 % in the USSR to 11 % in western countries. The death rates in France, Nor-way and Sweden were four to seven times those in Poland, the USSR and Yugoslavia;
the rates for men aged 65 years and over showed less variation and differed by a factor of three to four. The etiology of this type of cancer is unclear, but hormonal factors are likely to be implicated.
The mortality rates for leukaemia differed little between the three groups of countries.
The known environmental hazards are un-likely to account for the majority of cases.
High doses of ionizing radiation un-doubtedly cause some types of leukaemia, al-though quantitative estimates of the impact of low doses are still being studied. Evidence on the role of electric and magnetic fields is inconclusive but any increase in risk appears to be very small (see Chapter 11). Occupa-tional exposure to some chemicals (such as chronic exposure to benzene) and the treat-ment of prior malignant diseases with che-motherapeutic agents are known risk factors for some forms of leukaemia, and infections may have a role in the etiology of some types of childhood leukaemia.
The incidence of cancer markedly exceeds the number of deaths that result. Relevant data are available for approximately 26 % of the Region’s population, but the coverage and quality of registration data varies signifi-cantly [20]. For western countries, however, incidence exceeded mortality by 1.4 times
(in men aged 65 years and over) to 4.5 times (in women aged 0–44 years) [21, 22]. For 1980, crude rates of cancer incidence (at all sites except the skin) were estimated to range from 243 to 374 cases per 100 000 males, and from 212 to 341 per 100 000 females, with lower numbers estimated for eastern Europe (defined as the CCEE without Yu-goslavia) [23].
Malignant melanoma of the skin shows markedly different trends in incidence and mortality rates. In general, it is not a fre-quent disease, comprising less than 1 % of all cases of cancer. A rapid increase in inci-dence (up to 20–30 % every five years), how-ever, has been observed in some populations in the last 2–3 decades [18]. The highest incidence in the Region is in the Nordic countries, but the incidence is increasing as fast in eastern Europe as in western coun-tries. The increase in mortality is much slower (some 10 % every five years), prob-ably owing to improved early diagnosis and treatment of less advanced cases. The most important current risk factor is intentional exposure to ultraviolet radiation while sun-bathing (see Chapter 11).
Projections made for some countries of the Region suggest that cancer mortality will increase. For EU countries, a 31 % increase (with 17 % attributed to the increasing pro-portion of older people in the population) was predicted to occur between 1982 and 2000 [24]. Another analysis predicts that, even if progress in screening programmes and treatment leads to reduced mortality in some populations, the incidence of cancer may still increase in the next 10 years [21].