Hereditary cancer in adults.

Primary genetic factors play a major etiologic role in approximately 5% to 10% of the total cancer burden. Since the bulk of hereditary forms of cancer lack premonitory physical stigmata of cancer risk, a well-orchestrated family history is mandatory for establishing a hereditary cancer syndrome diagnosis. Knowledge of the natural history of the particular hereditary form of cancer will aid the physician in the development and implementation of highly targeted surveillance strategies. Indeed, specific natural history features of cancer, particularly early age onset and multiple primary cancer excess, characterize the more than 200 mendelian inherited cancer syndromes. The veritable explosive developments in molecular biology now enable the identification of germline mutations so that, in certain hereditary cancers, a simple blood test will enable the physician to determine the cancer destiny of patients carrying the particular germline mutation.