Cancer is a genetic disorder. Although hereditary cancers account for only a small fraction of all tumors, most cancers are caused by a variable mix of heredity and environment that leads to accumulations of genetic alterations and then uncontrolled cell proliferations (Kops et al., 2005
). In addition, genetic alteration is one of the a few most important biological factors that determine the diagnosis and prognosis of different cancers and dictate the treatment strategies for cancer patients. Furthermore, cancer specific therapies based on specific genetic alterations have opened a brand new era of cancer treatment (Jiang et al., 2003
). This lecture will focus on the genetic basis and possible mechanisms of tumorigenesis, common types of cancer, the importance of genetic diagnosis of cancer, and the methodology of cancer genetic diagnosis (Pinkel and Albertson, 2005
The workshop will also review presymptomatic testing of hereditary cancers, focusing on hereditary breast cancer genes, BRCA1 and BRCA2. We will review the nature of the involved genes, and the tumor phenotypes. Genomic analyses of sporadic breast tumors and hereditary tumors will be presented. These studies highlight the variety of genomic alterations present in sporadic tumors and show the differences and similarities between sporadic and hereditary tumors. Clinical aspects of BRCA-mutation testing, patient management and disease prevention will be discussed.
Recent developments in tumor classification using genome-wide expression profiling on microarrays will be reviewed. Initial studies applying expression profiling to identify patients likely to benefit from particular therapeutic approaches will be discussed.