Gene Variants Identified
Published: 2018-01-04 |
Newly identified germline variations in a key tumor suppressor gene predispose individuals to develop leukemia as children and leave them with a 1-in-4 chance of developing a second cancer later. St. Jude Children's Research Hospital scientist led the study, which appears in the Journal of Clinical Oncology. Researchers sequenced the TP53 tumor suppressor gene in 3,858 children with acute lymphoblastic leukemia (ALL) and identified 22 high-risk germline variations. The variants were associated with reduced gene activity and were five times more frequent in pediatric ALL patients than individuals without the disease. Germline variations are usually inherited and carried in the DNA of every cell, not just in the DNA of tumor cells. The 26 patients in this study who carried the high-risk TP53 variants were also almost four times more likely than other pediatric ALL patients to die of their disease or related complications.
"These germline variations are a double whammy for carriers," said corresponding author Jun J. Yang, Ph.D., an associate member of the St. Jude Department of Pharmaceutical Sciences and Department of Oncology. "Not only is their risk of developing leukemia very high, they are also more likely to relapse or develop a second cancer."
The association between the high-risk variants and second cancers is so significant that St. Jude researchers are exploring how to help patients and families manage their risk, Yang said. "Maybe these patients should avoid certain ALL therapies in order to reduce their risk of developing a second cancer," he said. "I believe this finding may change treatment and follow-up for these high-risk patients."