Osteosarcoma is the most common primary bone tumor in children. Primary tumors are those originating in a specific place in the body rather than those that have spread from elsewhere. About 30 percent of children with osteosarcoma that has not spread from the bone and 60 percent of those whose tumors have spread do not survive.
"Overall, our results indicate that telomerase gene expression is associated with an unfavorable outcome for children being treated for osteosarcoma," said Jeffrey S. Dome, M.D., associate member in Hematology-Oncology at St. Jude. Dome is senior author of the JCO report. Robert P. Sanders, M.D., a St. Jude postdoctoral fellow, is the paper's first author.
Although study results are preliminary, they might lead to tests that could identify children at high risk for treatment failure or death. That could help physicians determine how to modify therapies to improve chances of success in the future. The findings were based on a retrospective study of samples taken from osteosarcoma tumors of children treated at St. Jude during a 20-year period.
Telomerase is an enzyme that helps cancer cells survive and proliferate. The enzyme builds and maintains caps called telomeres that are located on the ends of chromosomes. These telomeres protect the chromosome ends from damage that otherwise would trigger apoptosis--the cell's self-destruct program.
Most cancers activate telomerase to maintain telomeres in order to protect their chromosomes and ensure the cells survive and multiply.