[Genetic predisposition to cancer]

Epidemiological studies indicate that environmental factors are more important for cancer development than inherited factors. However, clinical observations such as familial cancer clustering, constitute compelling evidence to the existence of inherited susceptibility to cancer. Few cancer-predisposing genes have been identified so far, by hard laboratory work and with the help of molecular biology tools. The predisposing genes that have been cloned can be used for DNA-based diagnosis. Genes inherited in altered form in familial cancers are the same genes that are altered in somatic cells of individuals with sporadic cancers. Identification of cancer genes through the study of rare families in which susceptibility to cancer is inherited, could have important consequences for diagnosis and treatment of common cancers.