TIME-TREND ANALYSIS OF MORTALITY FROM MALIGNANT-TUMORS OF THE NERVOUS-SYSTEM IN SPAIN, 1952-1986

We analyzed time trends in mortality from malignant tumors of the nerv ous system (MTNS) in the adult Spanish population during the period 19 52-1986, using Poisson regression analysis of age at death, year of bi rth and year of death. During such period, mortality rose especially i n the elderly as well as among young and middle-aged men. We found two modest period effects, in both sexes attributed to changes in certifi cation practice. An ascending effect in cohorts born up to 1920 in mal es and females was attributed to improvements in ascertainment. A posi tive, progressive, cohort effect in males born post-1920 was detected. Mortality from MTNS in Spain was medium-high with a tendency to rise, most likely due to improvements in diagnosis and registration. From t his analysis, the existence of a true increase in incidence of brain g lioma among young and middle-aged male adults during recent decades is suggested.