Most people who are at high risk of getting the skin cancer because it runs in their family can't answer that question. Melanoma genetic testing has not been widely offered because it wasn't clear it would help, and the advice would be the same regardless of the results: Annual skin examinations by a doctor, monthly self-checks for spots or other changes, and caution in the sun.
And people with negative results may get a false sense of security and not take precautions.
But a new study by Utah researchers showed, for the first time, that revealing results helps patients protect themselves. Even patients who learned they didn't have the mutation did a better job of screening themselves.
That could pave the way to routine genetic testing among those with a family history of the disease, including among children.
"Not one patient reported regret at getting results," Lisa Aspinwall, the lead author and associate professor of psychology at the University of Utah, said Friday. "People said, 'I'd much rather know. It helps me prepare for going in the sun.' "
The research was published in the June edition of Cancer Epidemiology, Biomarkers & Prevention. Researchers started with a group of Utahns who already knew they had a family history of melanoma. The patients had previously participated in research that identified the specific CDKN2A/p16 mutation. Those with the mutation have a 76 percent lifetime risk of getting melanoma.
The Utahns had been counseled to take precautions in the sun and screen themselves, but they did not know whether they had the mutation.
Their self-screening practices were evaluated six months before getting the results and one month after. Monthly checks are important because the prognosis is better than when melanoma is caught early than when it's found at an advanced stage.
Presumably, these patients were already doing a good job of protecting themselves, because their family history alone doubled their risk of melanoma - from the 1 percent risk in the general population to a 2 percent chance.
But the study found that wasn't true.
Patients who tested positive for the mutation changed from doing too few self exams to doing more than recommended. In essence, they became as vigilant at checking their skin as patients who already had a melanoma.
Such overscreening can be a problem, however, because people are more apt to notice problems if they wait a few weeks between self exams.
Even patients who tested negative went from underscreening themselves to doing more routine monthly exams.
Since they are following the patients for two years, researchers will be able to see whether those behaviors stick.
Sancy Leachman, a co-author and director of the melanoma program at the Huntsman Cancer Institute, said patients deserve to know if they have the gene.
"Instead of being a lifeguard, maybe they will choose to do an indoor job," she said.
Still, a genetic test is not recommended for everyone. Only 10 percent of melanoma cases are hereditary. Leachman said only select patients should be tested, including those with a history of melanoma and those with a strong family history of the disease.
Salt Lake City-based Myriad Genetics offers the test for $745 and says most insurance companies cover the cost.
Utah researchers are now asking study participants about testing children. Aspinwall said many parents in high-risk families want to know, hoping it will change a teen's sunbathing habits.
Melanoma is on the rise. In 2005, 557 Utahns were diagnosed, up from 494 in 2004. It kills an average of 63 Utah residents a year; 62,480 Americans are expected to develop it this year. Whether you have the melanoma gene mutation or not, there are precautions all Utahns should take against skin cancer:
* Apply sunscreen with SPF 15 or higher 30 minutes before spending time outdoors and reapply every two hours;
* Cover up by wearing hats, long sleeves, and sunglasses;
* Avoid the sun between 10 a.m. and 4 p.m. when you are most likely to be exposed to the ultra- violet rays that damage and age your skin;
* Seek shade when you can't avoid the sun.
Source: Utah Department of Health and Utah Cancer Action Network