[Genetic research with stored human tissue: a coding procedure with optimal use of information and protection of privacy].

To answer research questions concerning the course of disease and the optimal treatment of hereditary breast cancer, genetic typing together with the clinical and tumour characteristics of breast cancer patients are an important source of information. Part of the incidence of breast cancer can be explained by BRCA1 and BRCA2 germline mutations, which with current techniques can be retrospectively analysed in stored, paraffin-embedded tissue samples. In view of the implications of BRCA1- or BRCA2-carrier status for patients and other family members and the lack of clear legal regulations regarding the procedures to be followed when analysis is performed on historical material and no individual informed consent can be asked from the patients, an appropriate procedure for coding such data or rendering it anonymous is of great importance. By using the coding procedure described in this article, it becomes possible to follow and to work out in greater detail the guidelines of the code for 'Proper secondary use of human tissue' of the Federation of Biomedical Scientific Societies and to use these valuable databases again in the future.