RESUMO
Breast cancer is an important cause of morbidity and mortality in Brazil. Some studies have analyzed the potential role of organochlorine compounds in breast cancer etiology. These chemical compounds have been widely used in agriculture and in vector-control programs in Brazil. A case-control study was carried out in the main cancer hospital of the Instituto Nacional de Câncer in Rio de Janeiro to investigate exposure to organochlorinated pesticides as a risk factor for breast cancer. We investigated 177 cases of invasive breast cancer at the hospital, between May 1995 and July 1996, and 350 controls selected among female visitors at the same hospital. In addition to information obtained from interviews, blood samples were taken, to analyze residual amounts of organochlorine by gas chromatography using an electron capture detector. [1,1-Dichloro-2, 2-bis(p-chlorophenyl)ethylene] (DDE) was determined in sera of 457 women from a total of 493 participants who had serum samples available. Residues of hexachlorobenzene were found in 11 women only. No statistically significant association was found between breast cancer risk and serum level of DDE or history of exposure to pesticides. Serum levels of DDE (ng/ml) were similar in patients (median = 3.1, mean = 5.1) and controls (median = 3.1, mean = 4.8) (p = 0.93). The age-adjusted odds ratio of breast cancer for women in the upper quintile compared with those in the lowest quintile was 0.90 (95% confidence interval 0.47-1.73). When adjusted for other variables, the risk remained not statistically significant (upper quintile odds ratio = 0.79, 95% confidence interval 0.39-1.60). In our hands, exposure to organochlorinated pesticides measured by history or serum analysis was thus not a risk factor for breast cancer.
Assuntos
Neoplasias da Mama/induzido quimicamente , Diclorodifenil Dicloroetileno/análogos & derivados , Inseticidas/efeitos adversos , Adulto , Idoso , Análise de Variância , Brasil/epidemiologia , Neoplasias da Mama/epidemiologia , Estudos de Casos e Controles , Diclorodifenil Dicloroetileno/efeitos adversos , Exposição Ambiental/efeitos adversos , Feminino , Humanos , Pessoa de Meia-Idade , Razão de ChancesRESUMO
Serum levels of organochlorine pesticides (OCP) were measured in agricultural workers from Rio de Janeiro State, Brazil. Blood samples from 26 volunteers (24 males, 02 females, 17-60 years old) were taken in October 1997. OCP residues (op'DDT pp'DDT, pp'DDD, pp'DDE, aldrin, dieldrin, endrin, heptachlor, heptachlor-epoxide, (alpha-, beta- and gamma-hexachlorocyclohexane, and hexachlorobenzene) were analyzed by gas chromatography with an electron capture detector. Tests detected pp'DDE in 16 out of 26 samples, but pp'DDE concentration exceeded 1.4 (microgram/L (i.e. 1.8, 2.4 and 4.4 microgram/L) in only 3 of these. beta-HCH was found in 6 (23.1%) out of 26 samples. In one sample (-HCH did not exceed 1.4 microgram/L, but in the remaining samples concentrations ranged from 1.4 to 5.3 microgram/L. The percentage of positive pp'DDE samples increased from the youngest /= 40 yrs: 100%). A similar trend was found for beta-HCH contamination (/= 40 yrs: 66.7%). Dieldrin was found in only one sample. No other OCP residue was found in the samples. Serum concentrations of OCPs found in this study are comparable to blood levels reported for the non-occupationally exposed population in Brazil and elsewhere.