Santhosh Upadhyaya, MD, Pediatric Hematologist from St. Jude Children’s Research Hospital speaks about ATRT molecular groups: looking at the biology from the clinic.
Atypical teratoid rhabdoid tumor (ATRT) is a rare form of brain tumor that often affects children. Scientists at St. Jude Children’s Research Hospital studied the molecular groups of ATRT and correlated them with clinical results using evidence from two clinical trials. Clinical Cancer Research, a publication of the American Association for Cancer Research, published a paper outlining the findings today.
"If you look at the biology of ATRT, we have learned in the last few years that this is not a single disease but instead there are at least three biologically different groups of the same disease," said first and corresponding author Santhosh Upadhyaya, M.D., St. Jude Department of Oncology. "But what are the outcomes for these different groups? That is where the current St. Jude study offers insight into how these different groups of ATRT can present, and what their outcomes may be with different treatment regimens."
ATRT has been categorized into three molecular groups: ATRT-MYC, ATRT-SHH, and ATRT-TYR. Researchers examined the treatment results of 74 children with ATRT using data from the SJYC07 and SJMB03 clinical trials. Since ATRT is a rare pediatric cancer, this is one of the largest populations of children with the disease.
ATRT-TYR is more common in children under the age of three and is less likely to spread, according to the results. They also discovered that ATRT-SHH is more prevalent in very young children and has a higher risk of metastasis at the time of diagnosis. Furthermore, while ATRT-TYR children had the best overall response, ATRT-SHH and ATRT-MYC children had similar treatment responses in the absence of metastases.
The researchers also looked at the SMARCB1 gene in the blood, which is a common ATRT genetic mutation. The researchers found that about a third of the children examined had a SMARCB1 gene mutation. These children are more likely to have the ATRT-SHH community and grow ATRT at a younger age. The researchers discovered that having this abnormality had little effect on the results of treatment.
"While we have clearly made giant strides in understanding the molecular basis of ATRT, substantial progress is still required before treatment decisions can be made on the basis of different molecular groups," Upadhyaya said.