Guerrino Mezzanotte

Descriptive epidemiology of gastric cancer in Italy

National trends in death certification rates from cancer of the stomach in Italy over the period 1955 to 1979 were analyzed using a standard cross‐sectional approach and a log‐linear Poisson model to isolate the effects of birth cohort, calendar period, and age. Overall, age‐standardized death certification rates decreased from 47.04 to 30.74/100,000 males (average annual rate of change, assuming that the decrease has been constant, ‐1.8%) and from 34.55 to 19.27/100,000 females (average annual rate of change ‐2.4%). The decreases were even larger in middle age for both sexes. Both cohort and period of death curves were markedly downwards. However, cohort values did not decrease for generations born around the second world war (1935–1945), thus indirectly confirming the importance of (dietary) habits in childhood on subsequent gastric cancer risk. Further, the geographic distribution of certified mortality from gastric cancer in the 95 Italian provinces over the period 1975 to 1977 was analyzed. Death certification rates were about 10% lower for both sexes in the 14 provinces including the largest urban concentrations (over 250,000 inhabitants) than in the remaining areas. This finding might be related to earlier availability of modern food processing and storage in urban areas. It is, however, more difficult to explain the lower mortality rates (about 50% in both sexes) in the southern compared with the central and northern areas, since southern Italy is the less developed part of the country. Likewise, there appears to be at present little satisfactory explanation for the several clusters of exceedingly high mortality areas scattered in northern and central Italy, since some of these areas are several hundred kilometers apart, and there is no obvious common denominator in diet or other environmental factors that may explain their highergastric cancer mortality rates.

Cancer mortality in broad Italian geographical areas 1975-1977.

Death certification rates from various cancers or groups of cancers in broad Italian geographical areas (North/Center/South) over the period 1975-1977 were analyzed. In both sexes, there was a clear North/South gradient, with considerably higher rates in the North for total cancer mortality as well as for most common neoplasms. The geographical variation was more marked in males (North/South ratio for total cancer mortality = 1.75 at all ages and 1.70 truncated 35-64 years) than in females (ratio = 1.48 at all ages and 1.28 truncated 35-64). Although, in general terms, the present results confirm previous analyses of cancer mortality in Italy, a few interesting tendencies should be noted. First, the geographical differences in the mid-late 1970s were much more marked for tobacco-related cancers (a factor of over two in males in the North/South ratio) than for other chiefly epithelial carcinomas or nonepithelial cancers. In general, variations for nontobacco-related cancers tended to level off over more recent calendar periods. However, there was little tendency towards decreasing differences in gastric cancer mortality (which was markedly elevated in the North and Center), at least in males. During the 1970s death certification rates from cancer of the (cervix) uteri decreased in northern and central more than in southern Italy. This pattern of trends may have been influenced by a different impact of cervical screening in various areas of the country.

Trends in multiple births in Italy: 1955–1983

Summary. On the basis of the numbers of single and multiple births routinely collected by the Central Institute of Statistics, trends in multiple births in Italy over the period 1955–1983 were analyzed. Between 1955 and 1983 the frequency of multiple births declined by about 25% (from 12–6/1000 deliveries to 9‐6/1000 deliveries). The downward trend was constant until the early 1970s when rates tended to level off and increase slightly. This finding was largely attributable to trends in dizygotic rates, monozygotic births being approximately constant over the period considered. Multiple birth rates rose till age 35–39, being more than two times higher in this age group than in teenagers, but flattened off in the subsequent strata of age: this finding was constant over the period considered. Despite the general decreasing trend, the regional differences persisted largely unchanged, multiple birth rates being about 30% higher in Southern (and less developed areas) of the country than in the North of Italy. Geographic differences were limited to dizygotic pregnancies, monozygotic rates being constant (about 4/1000 pregnancies) in various areas.

Mortality from alcohol related disease in Italy.

Trends in death certification rates from the five major alcohol related causes of death in Italy (cancers of the mouth or pharynx, oesophagus, larynx, liver and cirrhosis of the liver) were analysed over a period (1955-79) in which per capita alcohol consumption almost trebled. Age standardised mortality from liver cirrhosis almost doubled in males and increased over 70% in females. In males, mortality from cancers of the upper digestive or respiratory tract showed increases of between 27% and 44%, and liver cancer increased by over 100%. In the late 1970s, the four alcohol related cancer sites accounted for about 12% of all cancer deaths in males and 4.5% in females. Mortality from liver cirrhosis alone accounted for 4.8% of all deaths in males (9.2% of manpower years lost) and 2.3% in females (6.3% manpower years lost) in females. These figures were even higher in selected areas of north eastern Italy, where alcohol consumption is greater. In absolute terms, the upward trends observed correspond to about 10,000 excess deaths per year in the late 1970s compared with rates observed two decades earlier and are thus second only to the increase in tobacco related causes of death over the same calendar period.

Cancer survival from the incident cases of the Registry of Vaud, Switzerland.

Survival statistics from the incident cases of the Vaud Cancer Registry over the period 1974–1980 were computed on the basis of an active follow-up based on verification of vital status as to December 31, 1984. Product-moment crude and relative 5 to 10 year rates are presented in separate strata of sex, age and area of residence (urban or rural). Most of the rates are comparable with those in other published series from North America or Europe, but survival from gastric cancer (24% 5-year relative rates) tended to be higher, and that from bladder cancer (about 30 %) lower than in most other datasets. No significant difference in survival emerged according to residence in urban Lausanne vs surrounding (rural) areas. Interesting indications according to subsite (higher survival for the pyloric region vs the gastric fundus, but absence of substantial differences for various colon subsites), histology (higher rates for squamous carcinomas of the lung, seminomas of the testis or chronic lymphatic leukemias as compared with other histotypes), or site of origin (higher survival for lower limb melanomas), require further quantitative assessment from other population-based series. A Cox proportional hazard model applied to melanomatous skin cancers showed an Independent favorable effect on long-term prognosis of female gender and adverse implications for advanced age, stage at diagnosis and tumor site other than lower limb.

Maternal mortality in Italy, 1955 to 1984

Between 1955 and 1984 Italian maternal mortality steadily declined by about 90% (from 133.3 per 100,000 live-births in 1955 to 11.4 in 1984). Maternal mortality rose with age and was about tenfold higher in the highest risk group (greater than or equal to 40 years old) compared with the lowest risk group (less than 20 years old). Deaths in pregnancy with abortive outcomes represented about 8% to 10% of maternal mortality as a whole; these percentages were constant throughout the calendar period considered. Geographically, there was no noticeable reduction in the northern/southern mortality ratio, which was constantly about 0.75.

Trends in ectopic pregnancies and use of intrauterine devices in Lombardy, Italy 1979–1983

The frequency of ectopic pregnancies in Lombardy (a region in Northern Italy with a population of about 9 million inhabitants) over the period 1979-1983 was estimated using the Regional Hospital Discharge Registration System, where information is collected on all discharges from public and private hospitals. The ratio of ectopic pregnancies rose from 4.43/1000 pregnancies in 1979 to 4.93/1000 pregnancies in 1982 and flattened off in 1983 (4.78/1000 pregnancies). The frequency of ectopic pregnancies increased with maternal age from 2.30/1000 pregnancies in teenagers to 6.01/1000 pregnancies in women 30-39 years old, but remained constant thereafter (5.84/1000 pregnancies in women aged 40 or older). These trends were consistent with available information on intrauterine device (IUD) sales over the same calendar period. On the basis of a random subsample of the same dataset, we evaluated by means of a case-control approach, the relative risk of ectopic pregnancy in relation to IUD use. Current IUD users had an estimated age-adjusted relative risk of ectopic pregnancy of 3.6 (95% confidence interval = 1.4-8.0) in comparison with an hospital-based control group of non-pregnant women. In etio-pathological terms, the interpretation of this finding is not obvious since it is possible that IUD users are simply less protected than pill, barrier or other traditional method users against ectopic pregnancy. Nonetheless, on a public health scale, the impact of IUD on the incidence of ectopic pregnancy should be evaluated in relative terms of comparison with other methods and their utilisation in different populations.

Birth cohort, time, and age effects in Italian cancer mortality.

Italian death certification data from 1955 to 1979 for total cancer mortality and 30 cancer sites in the population aged 25 to 74, were analyzed using a log‐linear Poisson model to isolate the effects of birth cohort, calendar period of death, and age. The most frequent cohort pattern was characterized by increases up to the generations born between 1920 and 1930, followed by stabilization or a slight decrease. This pattern was evident for total cancer mortality in men, and for several common sites, including larynx, lung, esophagus, bladder, female breast, and ovary. Only four sites (pancreas, pleura, intestines in both sexes, and kidney in men) showed cohort values still rising in more recent generations. Stable cohort and period of death curves were observed for cancers of the prostate and testis, whereas trends were steadily going down for neoplasms of the stomach, and (cervix) uteri. Finally, there were a few discontinuous trends (e.g., in the case of brain neoplasms, leukemias, and lymphomas), which probably reflect different effects of improvements in diagnosis and/or treatment. Period of death values increased for lung and other tobacco related sites (chiefly in males) and, up to the early 1970s, for a few other common sites, including intestines, and the female breast. Downward trends over the calendar period were evident for cancers of the stomach and of the (cervix) uteri. Therefore, total cancer mortality trends over the calendar period of death were moderately increasing for men, and slightly decreasing for women. Cancer 59:1221‐1232, 1987.

Maternal cohort, time of stillbirth, and maternal age effects in Italian stillbirth mortality.

STUDY OBJECTIVE--The aim of the study was to investigate factors in stillbirth mortality in Italy. DESIGN--Italian stillbirth data from 1955 to 1979 were analysed using a log-linear Poisson model with arbitrary constraints on the parameters to identify the effects of maternal birth cohort, calendar period of stillbirth and maternal age. SETTING--Stillbirth data for the whole of Italy were obtained from the Italian Central Institute of Statistics for the years under examination. During this period the criteria for defining stillbirth did not change and the quality of birth registration was similar. MAIN RESULTS--Decreases in stillbirth mortality were marked and steady, starting for the generations born since 1920. A period effect in stillbirth trends was shown, but this was apparently smaller than the cohort trend. CONCLUSIONS--The cohort trend suggests that long term improvements in socioeconomic and general health conditions may be important factors in the diminishing stillbirth rates, as well as short term advances in obstetric care. Alternatively the cohort effect could be attributed, at least in part, to an age-period interaction, since the downward trends were more pronounced in younger women.

Clinically useful measures to assess the effectiveness of treatments: hints for a proper choice with special emphasis on cancer research.

Several absolute and relative measures useful to assess the consequences of treatments in cancer research are presented together with statistical methods suitable for computing the pertinent confidence intervals. The relationship of these measures with the parameters of the regression models commonly used in the analysis of survival data is elaborated upon. Three examples are elaborated, and conditions of interchangeability of the measures are discussed in detail. Finally, suggestions for the choice of the measure most appropriate for a specified data set are given.