BRAIN CANCER MORTALITY IN AN AGRICULTURAL REGION, RIO DE JANEIRO STATE, BRAZIL: A POPULATION-BASED AGE- PERIOD-COHORT STUDY

摘要

Background: Brain cancer etiology has been poorly understood. Several studies indicate that residents in agricultural regions have an increased mortality risk. Aims: To explore an age-period-cohort effect study on brain cancer mortality in Serrana Region, an agricultural area in Rio de Janeiro State, Brazil. Methods: This was a descriptive epidemiologic study of mortality brain cancer in residents ＞ 19 yr. either performed at an agricultural (Serrana Region) or a non-agricultural one (Metropolitan Region) during 1996 -2010. Trend analysis was carried out using Joinpoint regression, and the age-period-cohort effects ascertained using log-linear Poisson regression. Results: The estimated brain cancer mortality annual percentage change in Serrana Region was 3.8% (95% C.I. 0.8 and 5.6), while - 0.2 (95% C.I. -1.2 -0.7) at the Metropolitan Region. In the former, a cohort effect was observed with increased mortality risk ratios, MRR: comparatively to those born in 1945-49, men born in 1980-84 presented a MRR= 4.07 (95% C.I. 1.83-9.04), and those born in 1985-89, a MRR = 4.17 (CI95% 1.79 - 9.74). Increased risk ratios were not observed in the Metropolitan Region, while an age effect was observed in both areas. Conclusion: These findings support the hypothesis that residents in agricultural regions may have experienced an increased exposure to brain cancer risk factors. The observed cohort effect is suggestive that environmental exposures, such as pesticides and biological agents, among others related to rural activities, may represent important risk exposures involved in brain carcinogenesis.