Results Of Genetic Testing Need Expert Interpretation

Genetic Counselors Aid Patients

In today's ever-changing healthcare environment, cancer patients and their physicians are turning to computers and other technologies to help with complicated decisions concerning care. However, two new studies suggest nothing beats the human touch, according to reports in the Journal of the American Medical Association.

Educational "decision aids" for women worried about breast cancer work just fine, but they can never replace expert counseling from physicians or other health professionals, such as genetic counselors, the studies found.

"In the ideal world, these things are an educational tool, perhaps for use in a 'precounseling' session, " says Dr. Charis Eng, director of clinical cancer genetics at Ohio State University. "But otherwise, trained people absolutely need to be involved."

Complexities Require Knowledge

According to Dr. Eng, recent advances in diagnostic procedures and treatments, plus a wider understanding of the role of genetics in disease, has made decision-making on the part of patients and their physicians tougher than ever.

Especially in the area of genetics, there simply are not enough trained genetics counselors like Dr. Eng to go around - only about 400 in the US.

Nevertheless, "medicine is going to be pervaded by genetics and genomics," Dr. Eng says.

Relying on one's physician for up-to-date genetics information may be difficult, she says, because "most physicians aren't trained in this field."

With a lack of specific training, some physicians may not be able to interpret gene test results for women who worry they might have a genetic predisposition to breast cancer.

Many women with a family history of breast cancer may worry they carry the BRCA1 or BRCA2 gene variants that can raise cancer risk.

In the first study, researcher Dr. Michael J. Green and colleagues at Penn State College of Medicine compared the usefulness of an educational, interactive computer program he created against traditional in-person genetics counseling. The goal: To see how the computer program helped women come to grips with issues surrounding BRCA1/BRCA2.

The computer "decision aid" first outlines the causes of breast cancer, then talks about genetic inheritance of disease in general before focusing on specific genes such as BRCA1 and BRCA2.

"We found that for improving knowledge, the computer program and the genetic counseling were both very effective," Dr. Green says. "They both raised knowledge levels considerably."

"On the other hand, knowledge isn't everything," Dr. Green adds. "For lowering anxiety, counselors did better than the computer. People like talking to a counselor, they like that one-on-one interaction."

The second study, led by Timothy Whelan of Hamilton Health Services in Hamilton, Canada, examined the effectiveness of a "decision board" - a kind of flip chart - to help breast cancer patients make informed choices about whether to have a mastectomy or a less-radical lumpectomy.

The decision board guided women through various topics, such as "Treatment Choice," "Side Effects," and "Results of Treatment Choice for the Breast/for Survival."

The researchers found use of the chart "helpful in improving communication and enabling women to make a choice regarding treatment."

Genetics Field Ever-Expanding

But while they may be useful tools, Dr. Eng says computer programs or decision boards should not and cannot replace the advice of a well-informed physician or genetics counselor.

For one thing, she says, "Who's going to keep these things updated?" Genetics research is proceeding at an incredibly fast pace, she points out, so what seems like good information today may be obsolete a year from now.

The genetics of disease is also becoming increasingly complicated, with malignancies dependent on the interaction of a number of genes, not just a single mutation, Dr. Eng says.

Dr. Green agrees, stressing that his computer program "isn't designed to give people specific advice."

"It's not a substitute for talking to a healthcare professional," he says. "It's designed to provide information - it doesn't tell them whether or not to get tested, or their specific risks for breast cancer, it's much more general. If they have specific questions they should always talk to a treatment professional.

Always consult your physician for more information.

Genetic Testing Facts

According to the federal government's Human Genome Program, currently in the US no regulations are in place for evaluating the accuracy and reliability of genetic testing. Most genetic tests developed by labs are categorized as services, which the US Food and Drug Administration (FDA) does not regulate. Only a few states have established some regulatory guidelines.

The Human Genome Program states that a few companies have started marketing test kits directly to the public. Some of these companies make claims about how the kits not only test for disease but also serve as tools for customizing medicine, vitamins, and foods to each individual's genetic makeup.

Another concern by these federal experts is that individuals who purchase such kits will not seek out genetic counseling to help them interpret results and make the best possible decisions regarding their personal welfare. More information on these "questionable" test kits is available from Dubious Genetic Testing, an online report provided by Quackwatch.

Genetic Testing and Insurance

The Human Genome Program states that, in most cases, an individual will have to contact his or her insurance provider to see if genetic tests, which cost between $200 and $3000, are covered.

Usually insurance companies do not cover genetic tests. Those that do will have access to the results. Insured persons would need to decide whether they would want the insurance company to have this information.

States have a patchwork of genetic-information nondiscrimination laws, none of them comprehensive. Existing state laws differ in coverage, protections afforded, and enforcement schemes.

The National Conference of State Legislatures provides a listing of current legislation regarding genetic information and health insurance. The recent marketing of genetic test kits directly to consumers, may lead to an increase in demand for insurance coverage.

Online Resources

(Our Organization is not responsible for the content of Internet sites.)

American Cancer Society

American Society of Clinical Oncologists

Centers for Disease Control and Prevention (CDC)

Gene Tests, NIH

Human Genome Program

National Cancer Institute

National Conference of State Legislatures

National Institutes of Health (NIH)

National Library of Medicine

Susan G. Komen Breast Cancer Foundation

US Department of Heath and Human Services

QuackWatch

September 2004

Results Of Genetic Testing Need Expert Interpretation

Complexities Require Knowledge

Genetics Field Ever-Expanding

Genetic Testing Facts

Genetic Testing and Insurance

Genetics of Breast Cancer Defined

Online Resources

Genetics of Breast Cancer Defined

Hereditary breast ovarian cancer (HBOC) syndrome is characterized by the following features in a family:

Other factors that increase the chance that a family has the hereditary breast ovarian cancer syndrome include:

In 1990, DNA linkage studies on large families with the above characteristics identified the first gene associated with breast cancer. Scientists named this gene “breast cancer 1” or BRCA1 (pronounced brak-uh).

BRCA1 is located on chromosome 17. Mutations in the gene are transmitted in an autosomal dominant pattern in a family - a mutation or alteration in a gene that lies on one of the first 22 pairs of chromosomes, which, when present in one copy, causes a trait or disease to be expressed.

Since it was clear that not all breast cancer families were linked to BRCA1, studies continued and in 1994, scientists discovered another gene (similar to BRCA1), and named it BRCA2. BRCA2 is located on chromosome 13.

Mutations in this gene are also transmitted in an autosomal dominant pattern in a family.

Both BRCA1 and BRCA2 are tumor suppressor genes that usually have the job of controlling cell growth and cell death. Everyone has two BRCA1 (one on each chromosome #17) and two BRCA2 genes (one on each chromosome #13).

When a person has one altered or mutated copy of either the BRCA1 or BRCA2 gene, their risk for various types of cancer increases:

BRCA1 Mutation

BRCA2 Mutation

Both copies of a tumor suppressor gene must be altered or mutated before a person will develop cancer.

In HBOC, the first mutation is inherited from either the mother or father and is therefore present in all cells of the body. This is called a germline mutation.

Whether a person who has a germline mutation will develop cancer and where the cancer(s) will develop depends upon where (which cell type) the second mutation occurs.

For example, if the second mutation is in the ovary, then ovarian cancer may develop. If it is in the breast, breast cancer may develop.

The process of tumor development actually requires mutations in multiple growth control genes. Loss of both copies of BRCA1 or BRCA2 is just the first step in the process.

What causes these additional mutations to be acquired is unknown. Possible causes include chemical, physical, or biological environmental exposures, or chance errors in cell replication.

Some individuals who have inherited a germline BRCA1 or BRCA2 mutation never develop cancer because they never get the second mutation necessary to knock out the function of the gene and start the process of tumor formation.

This can make the cancer appear to skip generations in a family, when, in reality, the mutation is present.

Persons with a mutation, regardless of whether they develop cancer, however, have a 50/50 chance to pass the mutation on to the next generation.

It is also important to remember that the BRCA1 and BRCA2 genes are not located on the sex chromosomes. Therefore, mutations can be inherited from the mother or the father’s side of the family.

Always consult your physician for more information.