WEDNESDAY, Nov. 12, 2014 (HealthDay News) -- Many American doctors may not support genetic testing in patients without a major family history of certain illnesses, suggests a new survey of physicians.
When presented with the hypothetical case of a middle-aged man with a family history of cancer in an aunt and uncle, more than a third of 180 U.S. doctors surveyed said they wouldn't recommend any genetic testing. Almost half would only recommend testing for cancer genes, and fewer than one in five would recommend whole-genome testing, according to the survey.
The genome is the complete genetic "blueprint" for an individual.
So what's going on? "Most doctors still feel uncomfortable with genetic testing," said Dr. Robert Klitzman, who studies genetic testing and is a professor of psychiatry at Columbia University's Joseph Mailman School of Public Health in New York City.
"Most doctors feel uncomfortable with knowing how to order genetic information, interpret it and counsel patients," explained Klitzman, who was not part of the study.
And even when genetic testing is done, the results may provide plenty of frustrating uncertainty about a patient's future health, he said.
In some cases where potential treatment options are clearer, such as women with histories of breast and ovarian cancer on one side of the family, doctors may be likely to order genetic tests, Klitzman said. Genetic tests can indicate that certain women have much higher risks of breast and ovarian cancers, according to the National Cancer Institute.
The survey asked readers of The New England Journal of Medicine to consider genetic testing in a made-up 45-year-old patient who requested it. The hypothetical man didn't appear to have any significant risks based on his health or family history.
Doctors responded from 77 countries. The responses from the United States were similar overall to those in the rest of the world. Of the 929 respondents, 74 wrote comments and expressed concern about what to tell the patient if testing showed a risk of cancer. Would the patient be stressed out or even be able to do anything? What about cost and the potential for discrimination against the patient based on his medical future?
Some of the survey respondents said they wanted to get more information about illness in the patient's family. That approach makes sense, Klitzman said. If relatives have had cancer, he said, the next step is to figure out if they're on the same side of the family, which increases risk.
"Cancer genetics has moved faster, both in terms of recognition of the role of genetic factors in familial predisposition and in terms of treatment decision-making for actual cancers, than has most other areas of genomics in medicine," said Dr. Bruce Korf, professor of genetics at the University of Alabama. "This may in part be due to the fact that cancer is very common and also to the fact that cancer is at its heart a genetic disease, and therefore the genes were more accessible to identification."
In a case like this one, Klitzman said, it's important for physicians to talk to patients about what they expect to learn from genetic testing: "What does he want, why does he want it and what will he do with the information?" When it comes to a higher risk of disease, "some people say 'I'm glad I got that information,' others say 'I don't even want to know about it unless there's something I can do about it.'"
Korf, who's familiar with the survey findings, said "many of the issues of concern can be, and are, successfully managed on a routine basis." As for cost, he said single gene tests can run hundreds or thousands of dollars depending on the complexity of the testing. Whole genome tests can cost $7,000 to $10,000, according to Korf.
What should patients do if they are concerned about their genetic risk? Both Klitzman and Korf recommended seeing a genetic counselor.
Korf said physicians need better awareness about the potential for genetic testing. "It is likely that genomic testing will become routine, and physicians will learn to incorporate this just as they have adopted other advanced technologies in medical practice."
The report appears in the Nov. 13 issue of The New England Journal of Medicine.
For more about genetic testing, try the U.S. National Library of Medicine.