Intracranial gliomas in Ferrara, Italy, 1976 to 1991

We planned a descriptive study on the incidence of intracranial gliomas spanning a 16-year period (1976-1991) in the Local Health Service 31 of Ferrara, Northern Italy.

We used a complete enumeration approach by reviewing all the possible sources of case collection available in the study area.

The mean annual incidence rate was 5.8 new cases per 100,000 population (6.96 for men and 4.78 for women; p < 0.05), resulting in 4.7 per 100,000 when directly adjusted to the Italian population. The age-specific incidences showed a small peak in childhood, an increase with age, reaching a maximum in the age group 60 to 64 and then a decline in the elderly. This pattern is similar for both sexes. The adjusted rates increased from 3.94 per 100,000 population in the first five-year period to 5.6 per 100,000 in the third (a nonsignificant difference). The distribution of cases within the study area was substantially uniform.

The incidence rates of Ferrara fell into the middle-high values so far reported and confirmed the male preponderance found in previous studies. The age-related pattern is similar to that observed, with few exceptions, in other surveys. Like other authors we did not find a significant temporal trend, although the incidence rates tended to increase with time. The data encourage further, wider epidemiological studies of a prospective nature.