Genetic Indicators for Likelihood of Secondary Adulthood Cancer

According to a new study, two genetic variations may exist that would predict which childhood Hodgkin’s lymphoma patients are at highest risk for secondary cancer in adulthood. The purpose of the study was to point out that despite the fact that Hodgkin’s lymphoma is one of the most treatable cancers around, pediatric survivors tend to face more of a risk for radiation-therapy induced second malignant neoplasms.

Kenan Onel, MD, PhD, associate professor of pediatrics at the University of Chicago, Illinois, and senior author of the study expounded on the findings:

"The idea is that different exposures elicit different cellular responses, each with its own set of genetic determinants," he told Medscape Medical News. "Thus, by not accounting for them in GWASs, you are by definition going to obscure and attenuate disease-related genetic signals.

"Thus, in the absence of exposure information, they will appear neutral in genetic studies and not be identified," he added. "Our risk variants seem to be associated with risk for second cancers in Hodgkin's lymphoma patients treated under the age of 20, but not over the age of 20," he said, "and the average time to development of a second cancer is about 20 years.

"The next step is to identify more patients to study so that we can have more confidence in the clinical value of our findings," Dr. Onel explained. "Data from Stanford University suggest that some subsets of patients with Hodgkin's lymphoma can be successfully cured with chemotherapy alone, so there are radiation-therapy-free options.

"If the patient does need radiation, then the presence of the risk variants may suggest that the patients be closely monitored for second cancer, much the same way as a patient with a BRCA mutation would be followed," he pointed out.

"All of this is in the future of course," he added, "assuming our results stand up to further scrutiny."

The study was published online July 24 in Nature Medicine.