[Oncogenes and oncogene products--possibilities and significance of their detection].

Diagnosis- and/or prognosis-related alterations of (proto) oncogenes may be detected in neuroblastoma (N-myc), carcinoma of breast and ovary (HER2/neu), NHL (c-myc, bcl-2), CML (c-abl/bcr), and some other neoplasias. A wide variety of methods for the detection of gene alterations can be applied. The methods of detection have to be chosen according to the expected mechanisms of oncogene activation, the availability of adequately prepared tissue, and the technical standard of the laboratory. The sensitivity, specificity, and quantitation of morphological techniques (immunohistochemistry and in situ hybridization) is restricted and their results have to be interpreted most carefully. Whenever possible, at least two different techniques should be used, preferably on two different levels, i.e. RNA/DNA and protein. Furthermore, the combination of morphological and non morphological methods should be aspired.