According to the National Center for Health Statistics, unintentional injuries and accidents are the leading cause of death for all kids and teens between the ages of one and 19 in the U.S. Cancer ranks second for children ages 5 to 9, third for kids ages 10 to 14, and fourth for all other youth age groups.

Leukemia is no longer the deadliest children cancer in the U.S., according to a new report released by the Center for Disease Control and Prevention (CDC).

Treatments for kids with leukemia have improved so much that it is no longer the leading cause of cancer deaths in children, the top spot now belongs to brain cancer, the CDC said.

"The shift from leukemia to brain cancer is a noteworthy development in the history of childhood cancer as it was always leukemia until quite recently," said Sally Curtin, demographer and statistician at the NCHS, which is part of the CDC, in an email interview with Live Science.

According to statistics from 2014 (the most recent year for which statistics are available), those two diseases were accounted for slightly more than half of all cancer deaths among children and adolescents in America.

Nearly 30 percent of the estimated 1,960 childhood cancer deaths that year were caused by brain cancer, and 25 percent were the result of leukemia. An additional 10 percent were due to bone and articular cartilage cancers, 9 percent of thyroid and other endocrine gland cancers, and 8 percent to mesothelial and soft tissue cancers, according to CDC's National Center for Health Statistics.

"Major therapeutic advances" in the treatment of leukemia, has likely resulted in the increases in survivorship.

"The leukemia specialists have done a really great job of stratifying these patients to give them appropriate therapy based on whether they feel their tumors are more aggressive or not," said Dr. Peter Manley, pediatric neuro-oncologist at the Dana-Farber/Boston Children's Cancer and Blood Disorders Center, who was not involved in the new report.

But when we are talking about survival rates among children with brain tumors, there are no significant changes, Manley said.

However, the survival rates related to certain subtypes of brain tumors (low-grade gliomas for example) are constantly improving and that current research is very promising, he said. According to Manley, "There's some really interesting information that's coming out".

Brain cancer researchers are focusing on cancer genomics, as well as on using molecular analysis and genome sequencing to learn what causes the tumors to grow and what makes them abnormal, he said. They have also been developing drugs that target the molecules involved in cancer growth and spread.

"The information coming from this research is so impressive that my feeling is that we will continue to see a decline in deaths," Manley told Live Science.

"Overall, the important thing to take from this [report] is that, across the board, there are significantly [fewer] cancer deaths just in the last 15 years," Manley said. "So the hope is, in the next 15 years, we'll continue to see that decline."

 "Pediatric brain tumors have not become deadlier over the years - survival rates for these patients have stayed relatively flat for decades," David F. Arons, chief executive of the National Brain Tumor Society said in a statement. "The reason these patients now face the highest mortality rates is because while other areas of oncology have made great strides in recent years, pediatric brain tumor research has not generated advances that have translated into meaningful clinical benefit for the most vulnerable patients."

Arons also said that the report underscores the need for new and better treatments for children who are diagnosed with brain cancer. Knowing that pediatric cancer doesn't receive nearly as much national funding as adult cancers, it will be hard to do much about that.