Purpose: To study the gastric and colorectal cancer mortalities and their relation to the urban-industrialization in Baixada Santista, located in the southeastern region of Brazil.Methods: Selected from the registries of the State System of Data Analysis Foundation (SEADE) were 1105 deaths due to gastric cancer and 690 due to colorectal cancer (ICD 151) that occurred from 1980 to 1993 in males, above 10 years of age, residing in Baixada Santista. For each of these types of cancer, the standardized mortality rates, age-adjusted by world population in the 1960s, for 4 industrialized and 4 non-industrialized urban communities in that region were calculated. The ratios among those rates were calculated in order to compare the mortality in the periods 1980-93, 1980-1986, and 1987-1993.Results: Standardized mortality rates for colorectal cancer were significantly higher in industrialized area, with ratios of 1.6 [95% CI 1.22 -2.29], 1.6 [95% CI 1.2 -2.0], and 1.6 [95% CI 1.3 -2.0] in the periods 1980-86, 1987-1993 and 1980-93, respectively. Gastric cancer did not show any statistical difference between the industrialized and non-industrialized areas, but there was a significant decrease in BS from the period 1980-1986 to 1987-1993.Conclusions: The significant elevation of colorectal cancer mortality in the industrialized area could be related to exposure to numerous carcinogens such as aromatic hydrocarbon, organic-chloride, metals, and industrial-port dust present in the region. Alternatively, the non-significant difference in gastric cancer between industrialized and non-industrialized areas and significant decrease in the last few years could be predominately reflecting the advances in the quality of life in urban areas. These results require further case-control studies that could help with the analysis of the associations among cancer and environmental factors (occupational, urban-industrial, habit, and life condition) and genetic susceptibility. Parkin in 1993 1 , analyzing estimates for the world incidence of cancer for males up to the year 1985, observed that gastric cancer (GC) was in second place (25.4/100,000) and colorectal cancer (CRC) in third place (17.8/100,000). When the incidences among developed and developing countries were considered, he observed GC in first place in the former, including the tropical region of South America in which Brazil is situated, while CRC ranked second in all developed countries.In Brazil, the morbidity and mortality due to GC has risen, reaching first place among all kinds of cancer in the 1970s and 1980s, except in the more developed regions such as the south and southeast. In contrast, the mortality and incidence of CRC are not as high, and this type of cancer is not ranked among the first five 2,3 .Although the excessive mortality of GC and CRC has usually been associated with lifestyle in urban and industrialized areas, several authors have shown a relationship between these kinds of cancer and exposure to occupational carcinogenic agents 4-8 .

It seems that environmental and occupational exposure to carcinogenic chemical agents, related to the productive process in the industrial complex, is a significant factor in mortality due to cancer.

-Objectives:The industrialization process and nervous system cancer (NSC) mortality in a urban region of Brazil. Method: From registries of the State System of Data Analysis Foundation (SEADE), 103 males deaths by NSC (ICD-9) in Baixada Santista (BS), from 1980 to 1993 were selected. Mortality ratios were calculated comparing the standardized mortality rate for ages over 10 years old (G1) and for the age group from 35 to 64 years old, in the industrialized and non-industrialized areas in three periods : 1980-1993, 1980-86, 1987-93. Results: A statiscally significant high mortality was observed in the industrialized area, for ages over 10 in all periods and only from 1980 to 1993 for ages from 34 to 64. The highest mortality ratio occurred from 1980-86 for ages over 10 -4.12 (CI 1.79-9.42). Conclusion: High mortality was probably related to the environmental and occupational exposure to many organic and inorganic chemical substances, considered carcinogenics, such as aliphatic and aromatic hydrocarbons, organochlorinated, formaldehyde, nitrogenated compounds and heavy metals, found in the port and industrial complex. We discuss the importance of case-control studies in characterizing the association of these and other risk factors in the determination of NSC.KEY WORDS: occupational cancer, cancer mortality, cancer epidemiology, nervous system cancer; brain cancer. Mortalidade por câncer do sistema nervoso em uma área industrializada do Brasil 1980-1993RESUMO -Objetivo: Estudar o processo de industrialização e a mortalidade por câncer do sistema nervoso (CSN) em uma região urbana do Brasil. Método: Foram selecionados dos registros das Fundação Sistema Estadual de Análise de Dados Estatísticos (SEADE), 103 óbitos por CSN (ICD-9) ocorridos na Baixada Santista, no sexo masculino acima dos 10 anos, de 1980 a 1993. Calcularam-se as razões de mortalidade, padronizadas por idade, comparando as áreas industrializada e não industrializada, nos períodos de 1980-93, 1980-96 e 1987-93. Resultados: Observou-se excesso significante de mortalidade na área industrializada para a população acima de 10 anos, em todos os períodos -3.11 ) e 2.63 . Para o grupo de 35-64 anos o excesso ocorreu apenas no período de 1980-93 -2.46 (CI 1.20-5.11). Conclusão: Supõe-se que esse excesso relaciona-se à exposição ocupacional e ambiental a carcinogênicos presentes no complexo industrialportuário como: hidrocarbonetos aromáticos, órgano-clorados, compostos nitrogenados e metais. Estudos casocontrole são necessários para o estudo desses e de outros fatores de risco na determinação do CSN. PALAVRAS-CHAVE: câncer ocupacional, mortalidade por câncer, epidemiologia do câncer, câncer do sistema nervoso.