[Molecular diagnosis on gastrointestinal cancers].

Many of the genetic alterations related to carcinogenesis and progression such as gene amplification, deletion, mutation and overexpression can be analyzed on paraffin-embedded clinical materials. Genetic abnormalities of tumor suppressor gene such as p53 and APC (adenomatous polyposis coli) are good markers for differential diagnosis of gastrointestinal cancers. Gene amplification and overexpression of oncogenes and growth factors/receptors such as c-met, K-sam, c-erbB2, EGF and EGF receptor are biological marker of biological malignancy. Molecular diagnosis has been done in Hiroshima Medical Association Laboratory to make an objective diagnosis for border line lesions and to obtain information on the biological behavior of gastrointestinal cancers based on genetic alterations. Molecular analysis is a powerful tool to complement histological diagnosis of gastrointestinal lesions.