Genetic mutation links with age in neuroblastoma
Neuroblastoma is a cancer of children, and it arises from nerve tissue. The older children are at diagnosis, the less likely they are to survive despite treatment, and new genetic biomarkers might start to open the door to the mechanisms behind this, as well as lead to personalized medicine for some groups of neuroblastoma patients.
Age at diagnosis seems to predict outcome after treatment--around 88% of children 18 months or younger are predicted to survive, compared with 49% between 18 months and 11 years, dropping to 10% in patients diagnosed at 12 or above. To see if there was a genetic biomarker to mark this, the researchers sequenced the genome and analyzed the telomere length of tumor samples from 40 infants, children, and young adults with advanced metastatic neuroblastoma, and from 64 historic samples. They found that the gene ATRX was only mutated in patients who were 5 or older, and that the number of mutations in the genes rose as the age at diagnosis rose. Older patients were also likely to have a chronic or indolent form of the disease.
This research could suggest a subtype of neuroblastoma in older children compared with younger children. If validated, the results may change the way doctors think about this cancer, said co-author Richard Wilson, Ph.D., director of the Genome Institute at Washington University School of Medicine in St. Louis. "This suggests we may need to think about different treatment strategies for patients depending on whether or not they have the ATRX mutation," he said.
The researchers concluded: "The identification of ATRX mutations now provides a new biomarker that may assist in identifying patients who develop a chronic but progressive clinical course and thus may be candidates for altered risk-based therapies."
The team is screening approved drugs to try to find something that could target the gene mutation, leading to personalized medicine for this subgroup of patients, particularly those with the more chronic form of the disease.