DNA testing for cancer predisposition.

PURPOSE/OBJECTIVES: To describe and review scientific and regulatory aspects of molecular genetic technology in the context of DNA testing for cancer predisposition. DATA SOURCES: Published professional articles, texts, and proceedings; commercial testing companies; computerized data bases; and the World Wide Web. DATA SYNTHESIS: This article reviews the basic molecular biology (e.g., DNA, genes, chromosomes, DNA mutations) that is the foundation for indirect and direct methods of DNA testing for cancer predisposition. Key issues in DNA testing include who should be tested, provision of testing, and regulatory concerns. Benefits and problems of testing contribute to its current controversial status. CONCLUSIONS: Understanding the mechanisms of DNA testing for cancer requires knowledge of basic molecular biology. Family history of the cancer in question is a key indicator for predisposition testing. Accessing information regarding research-based testing is challenging. DNA testing for cancer predisposition is not a perfect test, as exemplified by issues related to test regulation and sensitivity. IMPLICATIONS FOR NURSING PRACTICE: Basic knowledge of DNA testing for cancer predisposition will help nurses to (a) have a better understanding of the indications for and ramifications of testing, (b) provide information about testing to patients and the lay public, (c) counsel patients and families at high risk for inherited cancers more effectively, and (d) interpret DNA test results.