High Incidence of Laryngeal Cancer in the Province of Torino (Italy)

A Study on the Geographical Pathology of Laryngeal, Bladder and Children Cancer in the Province of Torino

A previous report has shown that in the non-metropolitan areas of the province of Torino the incidence of cancer of the larynx in men during the period 1965–1969, although lower than in the town of Torino and its suburbs, was 3–6 times higher than in Great Britain, Norway, Sweden and Denmark. In the present study the distribution of these cancers was investigated in the 12 ecological areas and/or subareas forming the non-metropolitan areas of the province. A similar study for bladder cancer in adult men and all cancers (including leukaemias) in children, is also reported. In subareas 36, 37 and 42 of ecological area 01 (i.e., located NW of the capital and its suburbs) as well as in area 02 (located North of the province, around the town of Ivrea) a significant excess of laryngeal cancers have been diagnosed in adult men during the period 1965–1969. Cancer of the bladder was found in excess in men residing in subareas 37 and 43 of area 01 (geographically related to the town of Ciriè, where an epidemic of bladder cancer was recognized among workers of a chemical factory where 2-naphthylamine and benzidine have been widely used in the past), as well as in men residing in area 02. In addition, laryngeal cancer was found in excess among residents in Balangero (where a large asbestos-chrysotile mine has been in operation for a long time) and adjacent towns (observed 12, expected 5.14, p < 0.01). Bladder cancer was particularly frequent among residents in Ciriè and adjacent towns (19 cases vs. 9.18 expected, p < 0.01) as well as in those residing in Ivrea and adjacent towns (24 vs. 14.61 expected, p < 0.02). On the contrary, the whole area situated East and South of Torino and its suburbs seems to be a low-incidence area for both laryngeal and bladder cancer. For both tumor types the highest incidence was found in the town of Torino. Men residing in the 23 suburbs of Torino showed a high incidence of laryngeal cancer and a low incidence of bladder cancer. Cancers in children were fairly uniformly distributed throughout the whole province, including the capital.

Descriptive Epidemiology of Cancer of the Larynx in the Province of Torino, Italy

Age-standardized incidence rates of cancer of the larynx in men from 1965–1969 were 14.7/100,000/year in the city of Torino and 8.4 in the non-metropolitan area of the province. These rates are among the highest in Europe. The geographical distribution of cancer of the larynx has been investigated in the non-metropolitan area considering two geographical entities, i.e., the 291 towns and the 12 ecological zones/subzones of the area. The incidence of cancer of the larynx in men was unrelated to the population of towns in 1961, whereas it was positively correlated to indexes of general industrialization as well as to those related to industrialization in the mechanical processes. Tobacco and alcohol consumption have not been taken into account. In order to validate the methodology, the investigation was extended to bladder cancer and to cancer in children. The former was correlated with general and chemical + rubber industrialization, whereas the latter was not correlated with any industrial process.

Increase of Mortality Kate of Cancer of the Larynx in the Town of Torino and in Italy since 1951

Mortality rates of cancer of the larynx in the town of Torino, in the whole of Italy and in France during 1950–71 are reported. Age standardized mortality rates as well as mortality rates truncated to the period 35–64 years of age are reported in Table 1 for males and in Table 2 for females. Graph 1 represents age specific mortality rates for cancer of the larynx in the three areas in 1966–67. Graphs 2, 3 and 4 report mortality rates in males in the three ares for cohort of birth. All rates are annual/100.000. An increase of mortality for cancer of the larynx in men is well documented in the town of Torino. From 1951 to 1966 the mortality rate truncated to age 35–64 increased from 6.3 to 12.0. The proportion of mortality for cancer of the larynx/mortality for all cancers during the same period increased from 3.1 % to 5.4%. In Italy, the mortality rate in men aged 35–64 was 6.5 in 1952 and 9.3 in 1967: during the same period the proportion of mortality for cancer of the larynx/mortality for all cancers increased from 3.8 % to 4.4 %. In France, the tendency to an increase of mortality for laryngeal cancer after 1951 was absent or debatable, although both the mortality rates of cancer of the larynx and the proportion of mortality for cancer of the larynx/mortality for all cancers were consistently higher than in Italy or in Torino. However, in 1966–67 at ages 35–44 the mortality rate for cancer of the larynx in men was higher in Torino than in France (Graph 1).

Mortality among shipyard workers in Genoa, Italy

The dockyards of Genoa are exposed to many known or suspect carcinogenic agents, namely, asbestos, silica, polycyclic aromatic hydrocarbons, and halogenated hydrocarbons; other possibly harmful substances are trace amounts of aromatic amines, welding smokes, paints, and lipid-removing solvents. A cohort study of causes of death of 2190 dockyard workers in Genoa was conducted between January 1, 1960 and December 31, 1975. Mortality rates were calculated for 20 different occupational categories, for which there exist different levels of exposure to noxious substances. Two control groups were selected: the general male population of Genoa and all male employees (462) of San Martino Hospital, Genoa for the same period of time. Causes of death that demonstrated significant excesses for both control groups were: cancer of the colon, excluding the rectum; cancer of the larynx; cancer of the lung, bronchus, and trachea; cancer of the kidney, urinary bladder, and other urinary organs; respiratory diseases; and cirrhosis of the liver. The data obtained from these 20 job categories revealed different types and levels of risk for various carcinogenic agents.

Mortality from Esophageal Cancer in Piedmont, Italy

Piedmont is located at the borderline between Italy (where mortality from esophageal cancer is relatively low) and France and Switzerland (where it is relatively high). Therefore, it seemed of interest to investigate the mortality from this cancer in Piedmont. Age-adjusted yearly mortality rates for 1965–1969 were 4.3 and 0.8 per 100,000 for males and females, respectively. Rates were very similar in the town of Torino, in the 23 suburbs of the first belt, in the nonmetropolitan areas of the province of Torino, and in the other 5 provinces of Piedmont. In both sexes, the rates did not differ from those observed in Italy during 1966–1967, whereas rates for males were lower than the national rates for France and Switzerland (14.0 and 8.5/100,000/year, respectively). Rates for males were also lower than in the adjacent French departments of Savoie, Haute-Savoie, and Isère (where in 1967–1968 they ranged between 9 and 16). Mortality rates from esophageal cancer in the town of Torino were constant from 1951–1971. During the same period, mortality from laryngeal cancer in men doubled. This suggests that although some etiological agents (alcohol consumption and tobacco smoking) are common to esophageal and laryngeal cancer, the interplay between these 2 factors as well as that with other carcinogens is different for the 2 types of cancer.