The promises resulting from the decoding of the human genome have not been fulfilled to the extent as expected. At the same time it is fair to say that the results of recent genetic research have not been useless. In the area of familial cancer the clinical benefit of genetic testing for healthy family members is very convincing, where the risk of disease can be reduced substantially through preventive interventions. For example, prophylactic mastectomy and premenopausal ovariectomy can reduce the cancer risk in carriers of BRCA1 and BRCA2 mutations dramatically. In recent years, the research has moved towards the decoding of the genetic causes of sporadic cancers as well. Genome-wide and hypothesis-free association studies have linked different chromosome regions to cancer. By this, new insights into disease mechanisms could be gained, an important requirement for the development of diagnostics and drugs. However, what is missing is the evidence that the associated SNPs (Single Nucleotide Polymorphisms) could be useful for individual risk calculation or for stratification of the population into groups with different preventive or screening needs