9 research outputs found
Breast cancer risk in mothers of twins.
The risk of breast cancer associated with delivering a twin birth was examined in a population-based nested case-control study of nearly 4800 Swedish women with breast cancer and 47000 age-matched control subjects. All were aged less than 50 years and parous. After adjustment for age at first birth and parity, a 29% reduction in breast cancer risk was observed in mothers of twins relative to those who were not (odds ratio = 0.71, 95% confidence interval 0.55-0.91). These results provide evidence that women who bear twins are at reduced risk of breast cancer, one explanation for which may be their unusual levels of hormonal exposure
Breast cancer in Swedish women before age 50; evidence of a dual effect or completed pregnancy
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Confiabilidade e validade das declarações de óbito por câncer de boca no Município do Rio de Janeiro Reliability and accuracy of oral cancer as the reported underlying cause of death in the Municipality of Rio de Janeiro
As estatísticas de mortalidade constituem uma fonte bastante utilizada em estudos epidemiológicos de neoplasias. Com o objetivo de avaliar a confiabilidade e a validade da causa básica de morte "câncer de boca", no Município do Rio de Janeiro, selecionou-se no banco de dados da Secretaria Municipal de Saúde, todas as declarações de óbito (DOs) com essa causa básica, no ano de 1999. As DOs foram submetidas à nova codificação da causa básica, por técnico independente, e construiu-se formulário padronizado para coleta de dados clínicos e laboratoriais para a confirmação do diagnóstico nos prontuários médicos de cada caso. Foi considerado como padrão-ouro o diagnóstico de câncer de boca formulado com base no exame histopatológico e/ou história clínica. Observou-se concordância simples de 95,1% e coeficiente kappa de 0,93. O valor preditivo positivo correspondeu a 86,5%. Conclui-se que as estatísticas de mortalidade por neoplasia de boca no Município do Rio de Janeiro são confiáveis e que é boa a validade desta causa básica, possivelmente, por se tratar de sítio de fácil acesso para a inspeção direta e com maior facilidade de confirmação clínica.<br>Mortality statistics are frequently employed in cancer epidemiology studies. The aim of this research was to evaluate the reliability and validity of oral cavity cancer as the underlying cause of death reported on death certificates in the Municipality of Rio de Janeiro, Brazil. All death certificates since 1999 reporting this underlying cause of death were selected from the Municipal Mortality Information System. The death certificates were re-coded by an independent technician, and a standardized questionnaire was designed to collect clinical and laboratory data for diagnostic confirmation from patient records. Histopathological results and/or clinical history were considered as the gold standard to establish the diagnosis of cancer of the mouth. Reliability analysis showed a simple percentage agreement of 95.1% and a kappa coefficient of 0.93. Positive predictive value was 86.5%. Mortality statistics for oral cancer in Rio de Janeiro Municipality demonstrate good reliability and validity, possibly because diagnostic confirmation is facilitated by easy access to the tumor site