By Corinna Wu

Does Family History Matter?

Self-reporting of cancer by immigrants may be unreliable

By Corinna Wu

Immigrants are two-thirds less likely to report a family history of cancer than people who were born in the United States, according to a recent study in the Jan. 15 Cancer. The findings suggest that doctors can’t rely solely on asking patients about their family history when deciding whether to recommend cancer screening and genetic testing.

Family history of cancer is “one of the main pieces of information that physicians are using in order to make that decision,” says study lead author Heather Orom, a social psychologist at the Barbara Ann Karmanos Cancer Institute in Detroit. “Are people at higher risk for cancer? Should they be screened earlier or more aggressively?”

Orom and her colleagues analyzed data from the National Cancer Institute’s 2005 Health Information National Trends Survey, which questioned people about how they find and use cancer information. The survey encompassed a nationally representative sample of more than 5,000 people. Previous studies have found that self-reporting of family history of cancer is lower among blacks, Hispanics and Asians compared with whites, but this is the first study to examine the effect of nativity along with race and ethnicity.

“It’s a very interesting paper,” says Dezheng Huo, an epidemiologist in the Department of Health Studies at the University of Chicago. “It suggests that both immigration and race play a role.” Huo expected the rate of self-reporting of family history by immigrants to be lower than it is for non-immigrants but says he was surprised by just how low it is.

The study could not determine exactly why self-reporting is lower. But the reasons are likely to be complex. When someone says they have no family history of cancer, “is it really ‘no,’ or is it that they don’t know?” says Esther M. John, an epidemiologist and the principal investigator of the Northern California Family Registry for Breast Cancer. Cancer used to be referred to as “the c-word”—something one did not dare mention by name, John says. Because of that stigma, people may not have shared their diagnoses, even with relatives. Also, distance might make it harder for immigrants to communicate with family members in their native countries.

What’s more, John and her colleagues have found that minorities tend to report breast cancer history as accurately as whites, meaning “the reporting of cancer really depends on the type of cancer,” she says.

Orom says it’s also possible that the low reporting of family history of cancer by immigrants might reflect rates of the disease in developing countries, where the rates of many cancers are much lower than in the United States. “But the important thing to remember is that it doesn’t necessarily mean they don’t have a genetic predisposition for the disease,” she says. Once families move to the United States and life expectancy increases, a person’s genetic predisposition to cancer could have more time to be expressed.

Actual family histories would certainly be the gold standard to confirm self-reporting in these types of studies, according to Orom. But as Huo points out, finding and interviewing family members of immigrants is difficult, if not impossible.

Simply finding out from a patient—immigrant or not—whether a family member has had cancer is not entirely helpful, Huo adds. “You need to know how old they were, how long they had it, and what their relationship to the patient is,” he says. Many patients, no matter where they are from, are unlikely to know those details.