NEW YORK (GenomeWeb News) – A retrospective study of individuals with eye cancer suggests these patients favor genetic testing that provides hints about their risk of cancer metastasis, even if there aren't avenues available for improving the outcomes of those at higher risk.
In a paper appearing in the June issue of the Journal of Genetic Counseling, researchers from the University of California at Los Angeles asked hundreds of patients with ocular melanoma to fill in a questionnaire evaluating their opinions about genetic tests for metastasis risk and related issues. Of the nearly 100 individuals who responded, 97 percent said they were in favor of receiving prognostic information, regardless of whether it directly affected their treatment.
"The issue of genetic testing has been a huge source of clinical controversy," corresponding author Tara McCannel, co-director of the UCLA Jules Stein Eye Institute's Ophthalmic Oncology Center, said in a statement. "Our research demonstrates that it's valuable to give people these details, even when their disease is not presently treatable."
Choroidal melanoma is a cancer that arises in the pigmented layers of the retina or nearby blood vessels. It affects roughly four to seven Americans per million. About half of all those diagnosed with the cancer eventually develop metastases to other parts of the body. Once this occurs, individuals usually die within about a year, though systemic interventions are sometimes effective.
Although tumor size can help gauge an individual's metastasis risk, researchers have also been working to identify genetic markers to predict this cancer progression. For instance, about half of choroidal melanomas involve the loss of one copy of chromosome 3 and half of these metastasize within five years.
That has led to the development of using fluorescence in situ hybridization or high-density array mapping tests to assess chromosome 3 monosomy or disomy to identify patients who are at a slightly increased or decreased risk of metastasis. A UK study of almost 300 eye cancer patients found that 97 percent of those offered prognostic cytogenetic testing took it.
In an effort to determine whether American eye cancer patients favored prognostic testing, the researchers surveyed 171 eligible choroidal melanoma patients who'd been treated at the UCLA Jules Stein Eye Institute between early 2002 and late 2006. Of these, 99 completed and returned the survey.
Almost 97 percent of the individuals who replied were in favor of prognostic genetic tests. Most patients reportedly cited a "desire for information" as their reason for wanting the prognostic test, though an interest in using the information to plan for the future was also popular. Of the 92 patients who responded to a question about genetic counseling, 98 percent said such counseling should be offered for those receiving such tests.
"Everyone wants to know what their risk is for metastasis," co-author Annette Stanton, a UCLA psychology, psychiatry, and biobehavioral sciences researcher, said in a statement. "If the risk is low, it's a huge relief and emotional burden off patients' shoulders. If the risk is high, it enables patients to plan arrangements for their family and finances and make the most of their time alive."
For the 38 patients surveyed who had already had the chromosome 3 prognostic test, though, responses about the test's usefulness varied. The 34 percent of patients who'd been shown to have the lower risk chromosome 3 disomy generally thought the test was more useful than the 29 percent of individuals with monosomy or the 34 percent of individuals who got inconclusive results. More patients with monosomy than with inconclusive results rated the test as useful.
"We hope that these findings reduce clinical resistance and pave the way for prognostic testing to become the standard of care in the management of ocular melanoma," Stanton said.
Even so, the study authors conceded that their results need to be replicated in larger studies. They also acknowledged the possibility that survey non-respondents might have a different opinion than those who filled in the survey and noted that a prospective study might uncover different views than those expressed by patients retrospectively.
Finally, the researchers noted that prognostic tests should continue to be evaluated as they are changed and refined. "[A]s cytogenetic testing for prognosis in choroidal melanoma evolves, continued research on how patients use and adjust psychologically to this information will be necessary," they concluded.