Cancer genetic risk assessment for individuals at risk of familial breast cancer

Apr 19 2007

Since recent medical findings have revealed that some families have increased breast cancer risk, a number of people are turning to cancer genetic services to learn more.

Most often they leave satisfied and with less stress and worry about getting the disease, according to a new review by Welsh researchers.

Patients concerned about developing familial breast cancer, which relates to a genetic problem, are increasingly requesting referrals to genetic centers to have an assessment of their risk, for reassurance and counseling, or for genetic testing. This demand has led to the opening of a number of genetic clinics across the country specifically dedicated to cancer.

The systematic review aimed to evaluate what impact these genetic services are having on patients, and the reviewers weren't surprised to find positive results.

“Many people have spent years worrying about cancer in their family,” said review co-author Rachel Iredale, Ph.D. “A genetic risk assessment enables people to reach a better understanding of hereditary breast cancer, their own personal risk, and means access to additional services, such as extra mammography screening or genetic testing, is often easier. Most people are satisfied with the service they receive.”

The review appears in the current issue of The Cochrane Library , a publication of The Cochrane Collaboration, an international organization that evaluates research in all aspects of health care. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing trials on a topic.

According to the National Cancer Institute, more than 192,000 women in the U.S. learn they have breast cancer each year and about 5 percent to 10 percent of these women have a hereditary form.

A mutation or alteration of the BRCA1 or BRCA2 genes causes the known hereditary form. The NCI reports that women with a mutation in either gene are three to seven times more likely to develop breast cancer.

The Cochrane reviewers analyzed three studies comprising 1,251 women who underwent genetic risk assessment for hereditary breast cancer. Researchers assessed their understanding of cancer risk and level of satisfaction with genetic counseling.

Iredale and her colleagues at the Institute of Medical Genetics in Wales found that all studies showed that genetic counseling improved patients' psychological well-being and decreased their levels of anxiety and worry about developing cancer.

Two studies showed patients were highly satisfied with counseling. In one study, 82 percent said they liked counseling “very much,” and in the other studies, more than half found it “very useful.” All three studies showed that patients left with an improved knowledge of breast cancer overall.

In short, the reviewers concluded that having a risk assessment for familial cancer is beneficial for patients and Iredale predicted that as the public's knowledge about genetic links to cancer increases, so too will the need for more of these types of services.

“Demand for these genetic services is likely to increase as genetic predispositions to other common conditions, such as cardiovascular disease, become known,” she said. “Many of these conditions are not gender-specific, though, so both women and men would seek these new services.”

Apostolos Psychogios, M.D., a medical geneticist at Memorial Hospital in Savannah, Ga., agreed that demand for genetic testing will increase, but said the medical field is not quite prepared to handle the growth.

“Today there are only about 1,170 medical geneticists in the country who practice in a clinical setting,” he said. “This means there is about one clinical geneticist to every 1.5 to 2 million people. We are very few and with more genetic discoveries and advances in DNA testing on the horizon, we are not enough.”

Psychogios added that at his institution, if a genetic risk assessment shows a patient has the BRCA1 or BRCA2 mutation, a team of health care professionals that includes a geneticist, an oncologist and a genetic counselor are involved in helping the patient make an informed decision on how to proceed.

The Cochrane Collaboration is an international nonprofit, independent organization that produces and disseminates systematic reviews of health care interventions and promotes the search for evidence in the form of clinical trials and other studies of interventions. Visit http://www.cochrane.org for more information.

Sivell S, et al. Cancer genetic risk assessment for individuals at risk of familial breast cancer (Review). Cochrane Database of Systematic Reviews 2007, Issue 2.