Commentary Page

Genetic testing evokes a number of different images, depending on the audience. The reality is that genetic testing is best defined by its purpose. Used to confirm a suspected diagnosis, to predict the possibility of future disease or carrier status in unaffected individuals, or, finally, to predict response to therapy, genetic testing will become more and more a part of the medical landscape as the 21st Century unfolds.

The U.S. National Human Genome Research Institute  estimates that there are 900 genetic tests currently available through diagnostic laboratories. In the field of Oncology, mutations in both the BRCA1 and BRCA2 genes are characterized by predisposition to breast cancer and ovarian cancer as well as prostate cancer. Susceptibility for colon cancer is associated with identifiable genes functioning in oncogene over-expression and tumor suppressor gene inactivation with the net promotion of malignant cell growth. For these forms of cancer, mutations in the relevant genes identify individuals at risk, changing medical outlooks for families, healthcare providers and, at a population level, issues for insurers.

The ability to test for these mutations raises questions concerning access, cost and public attitude, including that of affected individuals and family members as well as the public at large. In many countries, the identification of issues related to genetic technologies and services is underway. Access to and public awareness of genetic testing issues is of concern to all stakeholders as is concern about possible genetic discrimination and violation of medical privacy.

The American Society of Clinical Oncology (ASCO) has adopted a policy statement on Genetic Testing for Cancer Susceptibility, recommending access to genetic testing only in the “setting of pre- and post-test counseling”, to ensure that patients and their families understand the risks and benefits of cancer early detection and strategies for prevention. This implies that access to genetic testing should be linked to access to professional counseling, raising reimbursement issues for both types of services.

Who, then, will pay for these services? ASCO advocates public and third-party coverage of genetic testing, counseling and medical services for all individuals at significantly increased risk of hereditary cancer. However, it is not yet clear whether or not private or government insurance plans will support both testing of those individuals with a definitive history of disease (diagnostic service benefit) as well for those with a strong family history of disease ( screening service benefit). Failure to insure the latter service will most certainly limit access for individuals with significant family cancer histories, who may be at risk and who may benefit from early intervention strategies.

Another important issue is the question of how much the individual in an affected family wants to know and how the information will contribute to his or her decision to seek medical care. In a recent survey in the U.S., the issue of interest in knowing cancer genetic risk was addressed. It was found that while colorectal cancer patients and their first-degree relatives were interested in knowing about genetic testing, they were reluctant to complete the procedure when informed about the potential benefits and costs for a multiplicity of reasons. On the other hand, the results of another study among individuals who did agree to genetic testing for cancer suggested that testing positive improved compliance with subsequent colorectal cancer screening recommendations.

Genetic testing should not produce undo anxiety but rather guide informed follow-up. A recent study addressed our intuitive belief that positive genetic testing results increases psychological stress. Among 279 high risk women who underwent testing for mutations in the BRCA1/BRCA2 genes, those testing positive did not exhibit increased psychological distress or perceived risk. Does this suggest that family members of affected individuals are resigned, unconcerned, or could it be that they simply do not understand the implications of a positive test result?

As medicine moves toward developing novel genetic tests in additional disciplines, including brain diseases, mental illnesses, cardiovascular disorders, and others, we will do well to apply the insights and lessons of genetic testing in oncology, as they unfold. It should always be kept in mind that a positively identified genetic predisposition to develop cancer does not represent the certainty of developing the disease. Policy will best address appropriate access, utility, and privacy when it identifies and accounts for the perspectives of all those individuals it affects.