Genetic Testing for Cancer Risk Assessment: A Review.

Both environmental factors and an inherited predisposition influence carcinogenesis. The direct role of inheritance in the development of cancer is evident in familial cancer syndromes. These syndromes predispose to cancer through the inheritance of a mutation in a single gene in affected carriers. While many inherited cancer syndromes are rare, an inherited predisposition is directly responsible for 5%-10% of all colon and breast cancers. Complex multigenic inheritance plays an important role in cancer predisposition for the population at large. The identification of genes responsible for an inherited predisposition to colon and breast cancer syndromes has directed public attention to genetic testing for susceptibility to cancer. Assays are currently available to determine individual susceptibility to specific cancers. Cancer genetic testing is currently a time-consuming and complex procedure which requires expertise in its application, interpretation, and follow-up strategic planning. This review discusses cancer genetics and its application to individual and family cancer risk assessment with particular emphasis on breast and colon cancer.