[Criteria of genetic predisposition to hereditary non polyposis colorectal cancers]

Clinical and histological characteristics of non polypoid colorectal cancers with an hereditary predisposition are presented. The various known genetic syndromes (hereditary non polyposis colorectal cancers, Lynch syndrome type I and type II, Torre-Muir's syndrome, hereditary flat adenoma syndrome) are discussed to find a possible correlation between this nosological classification and their molecular substratum. The main problem today, is to correctly define the population of hereditary predisposed patients to colon cancer, in order to seek and identify the major responsible gene. Any physician, specialist or not, should be encouraged to give the details of the cancer familial context of his patients, in order to aid the oncologist geneticist in his task.