Anxiety over cancer keeps people from genetic tests

Emotions and perceptions of personal risk combine to influence people's decisions about genetic testing for cancer.

How worried people are about getting cancer is the strongest predictor of whether they are willing to be tested for a cancer susceptibility gene, research is finding.

But it's not a straight linear relationship between worry and testing, a new study finds. Instead, people who are moderately distressed about their cancer risk are the most likely to get tested. And those with high levels of distress and those with the lowest distress opt against testing, finds Mount Sinai School of Medicine researcher Heiddis Valdimarsdottir, PhD, and her colleagues at Sloan-Kettering Cancer Institute.

"High levels of cancer-related distress were related to not coming in for testing," says Valdimarsdottir. "Clearly the distress is there, and it's predictive [of whether a woman will come in for testing] above and beyond family history. But the relationship is curvilinear."

The connection between worry and willingness to get tested is just one of many trends psychologists have uncovered as they rush to understand the psychosocial consequences of tests for cancer susceptibility genes. Studies are also finding that although people who test positive for a cancer gene are at some risk for psychological distress, it's a subset of people who decide not to get tested who may be at even higher risk.

Through their research, psychologists are focused on discovering the potential benefits and limitations of genetic tests for cancer, and determining which factors inhibit or encourage people to be tested. Knowing that, they say, will help them understand what type of information people need to make informed decisions about testing and who would most benefit from psychological counseling.

Answering those questions has become even more important now that any primary-care physician can administer tests for breast and colon cancer--an advancement that makes many psychological researchers uncomfortable.

"I don't think we have enough information," says Valdimarsdottir. "Most of the studies [on genetic testing] have been done with people who have been involved in genetic research for years. We don't know much about people off the street."

And some questions--such as "what's the impact of genetic testing on people who get an inconclusive result?"--haven't been tackled yet.

Meanwhile, many people are confused about who genetic testing is for and what the results mean. The two tests available for colon cancer and the two for breast cancer only cover 5 percent to 10 percent of the incidences of these cancers diagnosed in the United States each year and are only designed for people who have a history of those cancers in their families. That means 90 percent to 95 percent of cases aren't related to these genes--they could be related to some other as yet undiscovered gene or to some other, possibly environmental, factor.

In addition, testing positive for a breast-cancer susceptibility gene doesn't mean a woman will get breast cancer, only that her chance of getting breast cancer is higher than for the general population.

Ann-Marie Codori, PhD, and her colleagues at Johns Hopkins University School of Medicine, for example, find that among a group of 140 people in a hereditary colon-cancer registry, those who decide to get tested for a susceptibility gene are more worried that they will develop the disease than people who opt against testing.

"They have a stronger hunch they're going to get colon cancer, and they're more likely to think often about getting colon cancer," says Codori, who published her results last month in a special issue of the journal Cancer Epidemiology, Biomarkers and Prevention (Vol. 8, No. 4), which focused on psychosocial aspects of genetic testing.

Similarly, women who seek out genetic screening for breast cancer tend to have high levels of cancer-related distress, find Georgetown University's Caryn Lerman, PhD, and her colleagues.

However, the Georgetown researchers also found that people who have the highest rates of depression are the least likely to get tested. That was the result of a study of genetic testing for colon cancer published last month in the Journal of the American Medical Association (Vol. 281, No. 17, p. 1618_1622).

"Cancer-related worries may motivate people to be tested," postulates Lerman. "Whereas generalized symptoms [such as depression] may lead to lethargy, feelings of hopelessness and reduce the likelihood that a person will be tested."

In addition, Mount Sinai's Valdimarsdottir and her colleagues at Sloan-Kettering find that in a group of 105 women who have never before been counseled about genetic testing, those with the highest levels of cancer-related distress opt out of genetic testing. It's the women with middle levels of distress who decide to get tested, they find.

The findings that cancer-related worrying, above and beyond family history, predicts a person's willingness to be tested contrast with the factors physicians and genetic counselors often use to assess whether a person should get tested. Indeed, clinicians tend only to consider family history and other medical factors related to the risk of getting cancer. Such a discrepancy may lead to communication problems between patients and health-care providers about the appropriateness of testing, say psychologists.

While patients may want a test to relieve their worries, clinicians may see no reason to administer a test to someone with no family history of cancer, say the authors of the introductory article in the special issue of Cancer Epidemiology, Biomarkers and Prevention.

Worry about cancer risk may also play a role in a woman's decision to have a prophylactic mastectomy in the hope of avoiding ever developing cancer, says Michael Stefanek, PhD, director of the Basic Behavioral Research Branch at the National Cancer Institute (NCI).

In a study conducted before genetic tests for breast cancer were available, he and his colleagues found that the amount women worry about getting breast cancer is the strongest predictor of their willingness to undergo the extreme surgery. In fact, cancer-related worry was more influential than the women's family history or whether they'd had biopsies in the past.

"The degree to which women reported worrying about breast cancer on a day-to-day basis--saying that it's a daily part of their lives and it affects their activity levels and moods--predicts whether they consider the surgery and whether they decide to have the surgery," says Stefanek.

Now that the genetic tests are available, researchers have begun following people who test positive for cancer-susceptibility genes to see whether people take steps to prevent developing the disease by changing their diets, increasing exercise and getting regular screenings. Codori, for example, has preliminary evidence that people who test negative for one of the two known colon cancer-susceptibility genes--an inconclusive result because of limited test sensitivity--continue to get screened regularly for precancerous polyps.

Researchers are also interested in whether testing positive for a cancer-susceptibility gene increases a person's anxiety and overall psychological distress. To the surprise of many, so far, studies have found that people are not highly distressed by the news, says psychologist Robert T. Croyle, PhD, associate director for the Behavioral Research Program at NCI and a genetic testing researcher. Rather, they show small, clinically insignificant increases in anxiety that tend to disappear over time.

According to work by researchers such as Codori, that may be because people who opt for testing have greater confidence in their ability to cope with a positive result. That could mean that people who decide not to get tested are at higher risk for testing-related distress than people who decide to get tested, says Codori.

In fact, Georgetown's Lerman found just that in a recent study published in the Journal of Clinical Oncology (Vol. 16, No. 5, p. 1650_1654). People who had high levels of cancer-related distress before they underwent genetic counseling and subsequently decided not to be tested showed significant increases in distress over time. There was no such increase among people who were tested--even if they tested positive.

This finding suggests that many people are very concerned about cancer risk, but equally concerned about the risks of testing--including the risk of losing their insurance. This combination appears to be particularly distressful for people, says Lerman.

NCI's Croyle and his colleagues have also have begun to examine how one sibling's genetic-test results may impact brothers and sisters in families known to be at increased risk for the disease.

In particular, men who tested negative but whose siblings tested positive were just as distressed as people who tested positive.

"We may be tapping into a type of 'survivor guilt,'" says Croyle.

Interestingly, women didn't show signs of survivor guilt. Their reactions to the test results were primarily determined by their results alone, not those of their siblings. Men who showed the most psychological distress, the researchers found, were those who tested positive and who had siblings who decided not to get tested, presumably because of their worry for siblings who might be at increased risk for cancer, says Croyle.

These are just the first results of many studies under way to determine the psychological implications of genetic testing for families, he adds. Indeed, researchers have only begun to scratch the surface in their quest for understanding how the availability of genetic testing for cancer will influence people and their behaviors.

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