Gastric and colorectal cancer mortality in an urban and industrialized area of Brazil

Abstract

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 .

Aberrant crypt foci and colon cancer: comparison between a short- and medium-term bioassay for colon carcinogenesis using dimethylhydrazine in Wistar rats

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Geospatial Disparities and the Underlying Causes of Major Cancers for Women in Taiwan

“…The hot spots of colorectal and female sexual-organ cancers were located in areas of high levels of urbanization or high population density. Urbanization might be associated with increased risk of colorectal cancer [33,34], which is growing rapidly in China because of the influence of urbanization [35]. Among the cancers of the female sex organs, the incidence rates of breast cancer are higher in urban areas compared with rural areas in the United States [36].…”

Mortality in the Bedouin Population and Proximity to a Regional Industrial Complex

“…Increased mortality from respiratory diseases in men and women living in Teesside (England), near a constellation of petrochemical, steel, and other industries, has been suggested as a health effect indicator of local industrial air pollution (Bhopal et al 1998). The majority of ecological studies have shown increased mortality due to cancer in relation to residence in the vicinity of waste sites (Altavista et al 2004;Minichilli et al 2005) and industrial facilities (Yang et al 1997;Bhopal et al 1998;Williams and Jalaludin 1998;Medrado-Faria et al 2001;Litt and Burke 2002;Belli et al 2004;Parodi et al 2004;Casella et al 2005).…”