Mortalidade por cânceres gástrico e colorretal em uma área urbana-industrial do Brasil

OBJETIVO: Estudar a mortalidade por cânceres gástrico e colorretal na Baixada Santista, região Sudeste do Brasil, onde situa-se importante complexo urbano-industrial. MÉTODO: Dos registros da Fundação Sistema Estadual de Análise de Dados (SEADE), obteve-se 1105 óbitos por câncer gástrico (CID 153-154) e 690 por câncer colorretal (CID 151), ocorridos em homens acima dos dez anos, residentes na Baixada Santista no período de 1980 a 1993, que encontram-se distribuídos entre os quatro municípios vinculados ao complexo industrial-portuário (área industrializada) e os quatro municípios situados fora dele (área não industrializada). Para cada câncer e para as áreas foram calculadas as taxas de mortalidade, padronizadas pela população mundial de 1960. Calculou-se então as razões entre essas taxas nos períodos de 1980-93, 1980-86 e 1987-93. RESULTADOS: As taxas de mortalidade para o câncer colorretal foram significantemente mais altas na área industrializada com razões de 1,6 [IC 1,22 -- 2,29], 1,6 [IC 1,2 -- 2,0] e 1,6 [IC 1,3 -- 2,0], respectivamente nos períodos de 1980-86, 1987-93 e 1980-93. O câncer gástrico não apresentou diferença entre as áreas industrializadas e não industrializadas, mas decresceu significantemente na Baixada Santista entre os períodos de 1980-86 e 1987-93. CONCLUSÕES: O excesso de mortalidade por câncer colorretal na área industrializada pode estar relacionado com a exposição a numerosos carcinogênicos orgânicos (hidrocarbonetos aromáticos e alifáticos clorados) e metais (cádmio, cromo e níquel) presentes na região. A diferença não significante para o câncer gástrico entre as duas áreas e o decréscimo nos últimos anos estaria refletindo predominantemente os avanços na qualidade de vida nas áreas urbanas. Esses resultados demandam a realização de estudos caso-controle para analisar as associações entre esses cânceres e os fatores ambientais (ocupacionais, urbano-industriais, hábitos, condições de vida e suscetibilidade genética).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 (ICD 153--154) 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

Visual field losses in workers exposed to mercury vapor

Visual field losses associated with mercury (Hg) exposure have only been assessed in patients exposed to methylmercury. Here we evaluate the automated visual field in 35 ex-workers (30 males; 44.20+/-5.92 years) occupationaly exposed to mercury vapor and 34 controls (21 males; 43.29+/-8.33 years). Visual fields were analyzed with the Humphrey Field Analyzer II (model 750i) using two tests: the standard automated perimetry (SAP, white-on-white) and the short wavelength automated perimetry (SWAP, blue-on-yellow) at 76 locations within a 27 degrees central visual field. Results were analyzed as the mean of the sensitivities measured at the fovea, and at five successive concentric rings, of increasing eccentricity, within the central field. Compared to controls, visual field sensitivities of the experimental group measured using SAP were lower for the fovea as well as for all five eccentricity rings (p<0.05). Sensitivities were significantly lower in the SWAP test (p<0.05) for four of the five extra-foveal eccentricity rings; they were not significant for the fovea (p = 0.584) or for the 15 degrees eccentricity ring (p = 0.965). These results suggest a widespread reduction of sensitivity in both visual field tests. Previous reports in the literature describe moderate to severe concentric constriction of the visual field in subjects with methylmercury intoxication measured manually with the Goldman perimeter. The present results amplify concerns regarding potential medical risks of exposure to environmental mercury sources by demonstrating significant and widespread reductions of visual sensitivity using the more reliable automated perimetry. (C) 2007 Elsevier Inc. All rights reserved

CYP1A2*1C, CYP2E1*5B, and GSTM1 polymorphisms are predictors of risk and poor outcome in head and neck squamous cell carcinoma patients

Head and neck squamous cell carcinoma (HNSCC) is associated with environmental factors, especially tobacco and alcohol consumption. Most of the carcinogens present in tobacco smoke are converted into DNA-reactive metabolites by cytochrome P450 (CYPs) enzymes and detoxification of these substances is performed by glutathione S-transferases (GSTs). It has been suggested that genetic alterations, such as polymorphisms, play an important role in tumorigenesis and HNSCC progression. The aim of this study was to investigate CYP1A1, CYP1A2, CYP2E1, GSTM1, and GSTT1 polymorphisms as risk factors in HNSCC and their association with clinicopathologic data. The patients comprised 153 individuals with HNSCC (cases) and 145 with no current or previous diagnosis of cancer (controls). Genotyping of the single nucleotide polymorphisms (SNPs) of the CYP1A1, CYP1A2, and CYP2E1 genes was performed by PCR-RFLP and the GSTM1 and GSTT1 copy number polymorphisms (CNPs) were analyzed by PCR-multiplex. As expected, a significant difference was detected for tobacco and alcohol consumption between cases and controls (P < 0.001). It was observed that the CYP1A2*1D (OR = 16.24) variant and GSTM1 null alleles (OR = 0.02) confer increased risk of HNSCC development (P < 0.001). In addition, head and neck cancer alcohol consumers were more frequently associated with the CYP2E1*5B variant allele than control alcohol users (P < 0.0001, OR = 190.6). The CYP1A2*1C polymorphism was associated with tumor recurrence (log-rank test, P = 0.0161). The CYP2E1*5B and GSTM1 null alleles were significantly associated with advanced clinical stages (T3 + T4; P = 0.022 and P = 0.028, respectively). Overall, the findings suggested that the genetic polymorphisms studied are predictors of risk and are also associated with tumor recurrence, since they are important for determining the parameters associated with tumor progression and poor outcomes in HNSCC. (C) 2009 Elsevier Ltd. All rights reserved.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo[FAPESP 04/00639-2]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo[CEPID/FAPESP 98/14335]National Council for Scientific and Technological Development (CNPq