[The state of the art of hereditary cancer studies]

During the last two decades, many genes responsible for hereditary cancer syndromes have been isolated. Based on the accumulating genetic information, genetic testing for both patients and the relatives is carried out in hospitals and clinics, and the clinical significance has been investigated. In addition to the genetic analyses of known genes and the functional analyses of the gene products, the recent research trends in hereditary cancer studies tend to move into the second era of research strategies including the isolation of novel genes responsible for remaining hereditary cancers, associated studies for finding cancer-susceptibility variants and the comprehensive analyses of expression profiles in tumors. Such new strategies are not only important to elucidate the pathophysiological mechanism of each hereditary cancer but may provide a potential application of tailor-made cancer therapy depending on the mutation status because many of the gene products seem to participate in the chemosensitivity of cancer cells. Furthermore, the research efforts have been expected to develop novel strategies for cancer prevention, diagnostics and therapeutics. In this paper, we have outlined the state of the art of studies on hereditary cancer syndrome, focusing on familial breast cancer and hereditary non-polyposis colorectal cancer.