6.1 INTRODUCTION
Cancers account for about 22% of all deaths in European countries. Cancer occurrence differs greatly between and within countries (Levi et al, 1989) and this is not simply an artefact due to the differences in the registration of data, but may be explained by variations in the levels of various aetiologic factors such as environmental exposure or specific life style habits such as smoking and diet (Armstrong et al, 1975; Doll and Peto, 1981). Generally, mortality rates for all cancers show a tendency to be lower in southern Europe than central Europe and Scotland.
Estimated incidence rates, based on mortality figures, for selected sites in the Europe Community have been calculated by Jensen et al (1990) for the period 1978– 82. Data for oesophagus, stomach, colon, lung, breast and ovary have already been presented in Chapter 4 (see Figs. 4.1 and Fig. 4.2 for example). In these figures Italy ranks respectively second and third for stomach and bladder cancer (estimated rates standardized to world population x 100,000 for males SR: 33.0 vs 40.3, Portugal and 22.8 vs 24.8, Denmark). It ranks fifth for lung (70.
0 vs 91.8, Belgium) and seventh for oesophageal and prostatic cancers (4.3 vs 11.
5, France and 28.8 vs 43.4, Germany). Conversely, it has been estimated that Italy has one of the lower incidence rates in Europe for cancer of the colon (16.0 vs 24.9, Germany), breast (52.6 vs 75.6, UK) and ovary (8.3 vs 15.5, UK) (Jensen et al, 1990).
Cancer rates for a whole country are average values that do not take account of marked differences existing within each country. Italy, in particular, has a very wide range of variation in site specific cancer incidence in different areas (North, Centre and South); this is illustrated in Fig. 6.1. These regions differ also in geodemographic factors, showing, for example, an increase for both sexes, from North to South, in the number of unemployed, illiterate persons and number of individuals living in the same house (crowding index) (Table 6.1).
Incidence data in Italy are available from nine cancer registries which cover about 10% of the whole population and are located mainly in the Northern
regions (Fig. 6.2). Incidence and mortality data for some site specific cancers in the Italian registries for the period 1983–87, together with mortality in the three geographical areas for 1985, are shown in Figs. 6.3 to 6.23. Trends in mortality/
increase of these neoplasms in Italy (1964–88) and in the various areas (North, Centre, South) (1970– 85) are presented in Figs. 6.24 to 6.39) (La Vecchia et al, 1986, 1990; Capocaccia et al, 1991; Decarli et al, 1991, 1992; Zanetti and Crosignani, 1992).
Fig. 6.1—Cancer mortality rates* by geographical areas (males, 1988).
*Age-standardized rates to Italian populatin 1971×10,000.
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Table 6.1—Geodemographic and environmental Italian parameters
Parameters Geographical areas
North Centre South
Territory (sq km) 99451 52057 111519
Forest (%) 33 31 54
Inhabitant/hospital bed (1988) 106 130 155
Unemployed:
males (%) (1990) 2.94 6.22 13.55
females (%) (1990) 8.59 15.68 31.88
Crowding index of the main house:
>1.60 (%) (1988) 1.33 2.64 6.72
Education of the head of the family:
illiterate (%) (1988) 7.85 10.40 20.81
secondary school (%) (1988) 26.54 25.81 23.83
degree (%) (1988) 4.51 5.99 5.01
For all cancers there is an evident decrease in rates from North to South (ie to the truly Mediterranean areas of the country). Total cancer mortality rates are around Fig. 6.2—Geographical distribution of Italian cancer registries.
35% higher for males and 25% for females in Northern areas in comparison to Southern regions (Table 6.2 and Fig. 6.1).
6.2
GASTROINTESTINAL CANCERS
Oesophageal cancer is one of the non-sexual-related site specific neoplasms with a high sex ratio. Incidence approximates to the mortality rates and is very high in Northern areas (Figs. 6.3 and 6.4) which compares with the highest values in European countries. Indeed, northern areas have repeatedly been found to have higher mortality values which correlate to intake of tobacco and alcohol (Zanetti and Crosignani, 1990) (SR for males: 7.3 in the North vs 1.9 in the South). These data are confirmed by the highest male incidence rate in Varese (7.7 vs 1.6 in Ragusa) (Fig. 6.3). The mean incidence value is 3.8 for males (Fig. 6.3) and 0.7 for females (Fig. 6.4). Mortality rates have shown a slight increase with time in males in Northern regions (from 6.2 in 1970 to 7.2 in 1985; Fig. 6.26) but not in females (Fig. 6.27).
Table 6.2—Cancer mortality rates* in Italian regions (1988). All sites
Males Females
North West Italy
Piemonte 20.4 11.8
Fig. 6.3—Oesophagus cancer incidence and mortality in Italy. Males.
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Males Females
Val d’Aosta 21.4 12.7
Lombardia 25.1 12.6
Liguria 20.3 11.6
North East Italy
Trentino AA 20.2 11.9
Veneto 23.5 11.3
Friuli VG 24.5 12.9
Emilia R 19.9 12.2
Total Northern Italy 22.5 12.1
Central Italy 18.3 11.0
Toscana 19.2 11.4
Umbria 16.7 10.5
Marche 16.4 9.4
Lazio 18.6 11.4
Southern Italy 15.1 9.7
Abruzzi 14.2 9.2
Molise 13.7 8.3
Campania 17.1 10.3
Puglia 15.8 10.0
Basilicata 13.6 9.5
Calabria 12.9 8.4
Sicilia 13.6 9.5
Sardegna 16.8 9.8
Total Italy 19.3 11.1
*Age-standardized rates to Italian population 1971x10,000.
Stomach cancer frequency is higher in Central and Northern regions (Fig. 6.5 and 6.6), the ratio between highest and lowest registries being around 2.5 (Firenze 40.1 and Ragusa 16.1 for males) (Fig. 6.5). Distribution by subsite reveals a higher frequency of cancers of the antrum, together with a high percentage of nonspecified sites due to inaccuracies in cancer notification (Fig. 6.7). The mean incidence rate is 27.0 for males and 13.0 for females.
Stomach cancer mortality has been decreasing throughout the country, from 29.6 to 18.9 for males and from 15.1 to 8.9 for females (Figs. 6.28 and 6.29) but this disease is still one of the most common neoplasms (Figs. 6.24 and 6.25). A more marked diminution is evident, nevertheless, in Northern and Central areas (around
—50%) than in the South (Fig. 6.28 and 6.29). Even if the aetiology of stomach cancer remains largely unknown, it is evident that changes occurred in high risk areas which represent the results of changes in dietary habits (including lower consumption of preserved foods). Analytical studies support the hypothesis of a
protective effect of fresh fruits and vegetables (see also Chapter 17) and, between micronutrients, such as → -tocopherol which is present at high levels in olive oil (see Chapter 13), which is used in large amounts in the rural areas and particularly in the more Mediterranean areas (Buiatti et al, 1990).
The range of mortality for colon cancer is about 2-fold from Northern to Southern areas (respectively SR around 11 and 6 for males) and mortality figures are approximately half the incidence (Figs. 6.8 and 6.9). The number of new cancer cases, occurring mostly in the sigmoid region (Fig. 6.10), is higher in Northern registries (Trieste 30.9, Parma 23.4 and Varese 24.0; males). Mean incidence rates are 20.7 for males and 15.5 for females (Figs. 6.8 and 6.9). The different rates observed among the areas could be partially attributed to different dietary intakes and in particular to a higher animal fat consumption (Zanetti and Crosignani, 1992).
When considering the statistics for cancer of the liver (Fig. 6.11) it should be kept in mind that there are difficulties concerning the distinction between primary and secondary tumours at this site. This problem is more relevant to the mortality statistics of this neoplasm which is suspected to be associated, at least in part, to a viral aetiology. Mean incidence values in Italy are 8.9 for males and 3.1 for females. The highest values are observed for males in Trieste (14.9), Varese (10.
6) and Torino (10.4) (Fig. 6.11) and for females in Latina (4.7) and Ragusa (3.6), affecting younger age groups in these areas than in the other regions.
Pancreatic cancer mortality rates have shown increasing values in all areas, but this trend could be attributable, at least in part, to the improvements in diagnostic techniques which occurred in the last ten years. Trieste has the highest Fig. 6.4—Oesophagus cancer incidence and mortality in Italy. Females.
140 CANCER EPIDEMIOLOGY IN ITALY [CH. 6
incidence rate in females (SR: 6.6) and has high rates in males also (9.8 compared to 10.2 in Parma, the highest SR) (Figs. 6.12 and 6.13).
6.3 LUNG CANCER
Lung cancer is the site with the highest incidence and mortality in the male population. Geographically, a decreasing mortality gradient from North (SR: 68.
3) to Centre (55.5) and South (44.3) is observed (Figs. 6.14 and 6.15). Incidence, too, is twofold higher in Northern areas, particularly Trieste (88.1) and Varese (83.6), with a mean value of 65.4 for males and 8.1 for females (Figs. 6.14 and 6.15). This neoplasm has dramatically increased in incidence in Italy during the last 20 years (Figs. 6.32 and 6.33) for both sexes (higher than 60% for females and 100% for males), with a more marked increment of mortality rate in the South (from 42.1 to 68.3 in the North and from 25.9 to 44.3 in the South; males).
6.4
FEMALE CANCERS
Sex-related cancers in females, ie breast and ovary, show similar patterns, with the highest mortality rate in the North (22.8, 5.8 in the North and 16.7, 3.4 in the South respectively) (Figs. 6.16 and 6.17). This gradient is confirmed by estimated incidence rates for breast cancer in 20 Italian regions (Fig. 6.18) (Micheli et al, 1992). For both sites, incidence values are elevated in the areas of Fig. 6.5—Stomach cancer incidence and mortality in Italy. Males.
Forli-Ravenna (64.8, 11.9 respectively), Varese (66.4, 10.7) and Genova (65.9 and 9.4). Mean national incidence rates are around 59.0 for breast and 9.2 for ovary. Breast cancer represents about 25% of all female cancers in Italian registries; within Europe, Italy occupies a medium-high position, similar to that of other industrialized countries (Zanetti and Crosignani, 1992). From 1970 to 1985 an increasing trend is observed for both cancers throughout the country (around 12% breast and 20% ovary in North and 18% and 32% in the South respectively) (Figs. 6.34 and 6.35). Ovarian cancer shares some risk factors with neoplasms of the breast, namely, hormonal correlations and, it has been suggested, dietary factors in terms of high consumption of calories and/or fats: this may explain the geographical variation in the incidence of these diseases (Boyle, 1988).
Mortality statistics for cancers of the uterus are not able to distinguish between cervical and corpus uteri which have two distinct pathologies from the aetiological point of view (a viral aetiology for the cervix and hormonal factors and obesity for corpus uteri). Mortality from cancer of the uterus (site not specified) is around 40% higher in Southern regions (SR: 6.8 vs 4.7, North) but has halved in the last 15 years (Fig. 6.36). Incidence data (Fig. 6.20) show that rates for cervical cancer are higher in the South (Ragusa 11.5 vs 7.2 Varese), but differences between the areas are less marked than was previously thought on the basis of mortality data (Zanetti and Crosignani, 1992). Corpus uteri incidence is higher in Varese (14.1) Firenze (13.1) and Ragusa (13.1), but nevertheless quite uniform rates are observed throughout the country (Figs. 6.19 and 6.20).
Fig. 6.6—Stomach cancer incidence and mortality in Italy. Females.
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6.5
OTHER CANCERS
Diet, particularly consumption of animal fats, is supposed to be an aetiological factor in cancer of the prostate (Snowdon et al, 1984). This tumour is more frequent in Northern areas (Fig. 6.21) and shows slowly increasing mortality trends with time (from 11.4 to 12.9 in the North and from 7.4 to 9.4 in the South) (Fig. 6.37). The highest incidence rate is observed in Trieste (Fig. 6.21; SR=34.
5): it is important, nevertheless, to remember that statistics on prostatic cancer occurrence may be influenced by casual findings (ie with autopsies).
The last cancer site we considered was the bladder, the incidence of which cancer is about fourfold higher in males. Environmental factors such as smoking and some occupation exposures are strongly suspected in the aetiology of this disease, together with a high consumption of animal fats and a low intake of vitamins (Riboli et al, 1991). Analysing the frequency of this tumour one must consider registration problems regarding multifocality and malignancy of the disease. Mortality rates present a narrow range in different areas (SR: 9.2 North, 8.9 Centre and 8.8 South for males) (Figs. 6.22 and 6.38) and the highest incidence values, with rates higher than 30 per 100,000 are observed in Firenze (36.1) and Trieste (33.8) (Figs. 6.22 and 6.23).
Differences in overall cancer risk in the different areas in Italy are supported by the analysis of incidence rates by sex and age group which show a trend towards low risk in the most Southern registries and high risks in Northern and Central areas (Zanetti and Crosignani, 1992). The cumulative risk of having a Fig. 6.7—Stomach cancer incidence in Italy (1983–87). Distribution by subsite.
tumour by the age of 75 years is higher in Varese (37 % in males and 23 % in females) and is lower in Latina (23% in males and 16% in females). In the country overall, the incidence rates increase in males with age to the power of five. In females incidence increases quickly until the age of 50–55 years and then slowly. This postmenopausal trend is attributable mostly to breast and gynaecological cancers (Zanetti and Crosignani, 1992).
6.6 CONCLUSION
In Italy nationwide statistics for cancer are available only for mortality, while incidence data are provided only by local registries that account for only a small part of the country and mostly in the Northern area. The mortality statistics derive from a relatively uniform source; nevertheless the range of variation in Italian regions is considerable, reflecting different socioeconomic and environmental situations (Decarli and La Vecchia, 1986).
Comparisons of cancer data show a North/South gradient for all sites considered, showing a similar distribution between males and females, with a higher frequency in northern areas (except for the uterus). This confirms the previously described lower cancer incidence in the Mediterranean areas, which in Italy corresponds to the southern part of the country.
Analysis of data shows that in general the trends with time for different cancer sites are similar in the different geographical areas. Generally, increasing rates Fig. 6.8—Colon cancer incidence and mortality in Italy. Males.
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are observed in both sexes for cancers of the pancreas, lung and bladder. Similar trends are present for cancers of the prostate in males and the breast and ovary in females. Neoplasms of the stomach and uterus show a decreasing trend, while a quite stable value is observed for tumours of the oesophagus and colon in males.
Geographical and temporal trends of some neoplasms may possibly be explained by the observed time variations of environmental factors such as smoking, reproductive habits and diet which could act as interactive or independent factors to influence the risk of these diseases.
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Boyle P (1988). Epidemiology of breast cancer. Bailliere’s Clin Oncol 2: 1–57.
Buiatti E, Palli D, Decarli A et al (1990). A case-control study of gastric cancer and diet in Italy. II. Association with nutrients. Int J Cancer 45: 896–901.
Capocaccia R, Farchi G, Prati S et al (1991). La mortalità in Italia nell’anno 1988.
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Decarli A, La Vecchia (1991). Cancer mortality in Italy, 1985–1987. Tumori 7: 1–6.
Decarli A, La Vecchia C (1992). Cancer mortality in Italy, 1988. Tumori 78: 69–74.
Fig. 6.9—Colon cancer incidence and mortality in Italy. Males.
Doll R, Peto R (1981). The causes of cancer: quantitative estimates of avoidable risks of cancer in United States today. J Nat Cancer Inst 66: 1191–1308.
Jensen OM, Esteve J, Moller H, Renard H (1990). Cancer in the European Community and its member states. Eur J Cancer 26: 1167–256.
La Vecchia C, Decarli A (1986). Cancer mortality in Italy. Temporal trends and geographical distribution. Eur J Cancer Oncology 22: 1425–9.
La Vecchia C, Negri E, Decarli A, Fasoli M, Cislaghi C (1990). Cancer mortality in Italy:
an overview of age specific and age-standardised trends from 1955 to 1984. Tumori 76: 87–166.
Levi F, Maisonneuve P, Filiberti R, La Vecchia C, Boyle P (1989). Cancer incidence and mortality in Europe. Sozial und Präventivmedizin 34.
Micheli A, Verdecchia A, Capocaccia R et al (1992). Estimated incidence and prevalence of females breast cancer in Italian regions. Tumori 78: 13–21.
Moller Jensen O, Estève J, Moller H, Renard H (1990). Eur J Cancer, Vol 26, 11/12:
1167–1256.
Riboli E, González CA, López-Abente G et al (1991). Diet and bladder cancer in Spain: a multi-centre case-control study. Int J Cancer 49: 214–19.
Snowdon DA, Phillips RL, Choi W (1984). Diet, obesity and risk of fatal prostate cancer.
Am J Epidem 120: 244–50.
Zanetti R, Crosignani P (1992). Cancer in Italy. Incidence data from cancer registries 1983–87. Lega Italiana per la Lotta contro i Tumori. Associazione Italiana di Epidemiologia.
Fig. 6.10—Colon cancer incidence in Italy (1983–87). Distribution by subsite.
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Fig. 6.11—Liver cancer incidence in Italy
Fig. 6.12—Pancreas cancer incidence and mortality in Italy. Males.
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Fig. 6.13—Pancreas cancer incidence and mortality in Italy. Females.
Fig. 6.14—Lung cancer incidence and mortality in Italy. Males.
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Fig. 6.15—Lung cancer incidence and mortality in Italy. Females.
Fig. 6.16—Breast cancer incidence and mortality in Italy.
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Fig. 6.17—Ovary cancer incidence and mortality in Italy.
Fig. 6.18—Breast cancer estimated incidence in Italian regions (1987).
Fig. 6.19—Uterus cancer incidence and mortality in Italy.
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Fig. 6.20—Uterus cancer incidence in Italy (1983–87). Distribution by subsite.
Fig. 6.21—Prostate cancer incidence and mortality in Italy.
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Fig. 6.22—Bladder cancer incidence and mortality in Italy. Males.
Fig. 6.23—Bladder cancer incidence and mortality in Italy. Females.
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Fig. 6.24—Cancer mortality in Italy 1964–88. Males.
Fig. 6.25—Cancer mortality in Italy, 1964–88. Females.
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Fig. 6.26—Oesophagus cancer mortality in Italian areas, 1970–85. Males.
Fig. 6.27—Oesophagus cancer mortality in Italian areas, 1970–85. Females.
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Fig. 6.28—Stomach cancer mortality in Italian areas, 1970–85. Males.
Fig. 6.29—Stomach cancer mortality in Italian areas, 1970–85. Females.
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Fig. 6.30—Colon cancer mortality in Italian areas, 1970–85. Males.
Fig. 6.31—Colon cancer mortality in Italian areas, 1970–85. Females.
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Fig. 6.32—Lung cancer mortality in Italian areas, 1970–85. Males.
Fig. 6.33—Lung cancer mortality in Italian areas, 1970–85. Females.
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Fig. 6.34—Breast cancer mortality in Italian areas, 1970–85.
Fig. 6.35—Ovary cancer mortality in Italian areas, 1970–85.
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Fig. 6.36—Uterus cancer mortality in Italian areas, 1970–85.
Fig. 6.37—Prostate cancer mortality in Italian areas, 1970–85.
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Fig. 6.38—Bladder cancer mortality in Italian areas, 1970–85. Males.
Fig. 6.39—Bladder cancer mortality in Italian areas, 1970–85. Females.
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