TUESDAY, Feb. 28, 2017 (HealthDay News) -- Children who survive cancer are living longer.

And one reason may be that fewer childhood cancers are treated with radiation today than were 20 years ago, researchers suggest.

Although the study can't prove a cause-and-effect link, the researchers found that as use of radiation in childhood cancers declined dramatically, so did the number of kids with cancers that returned.

Advertisement

"The most ominous late effect of pediatric cancer treatment is a second [cancer]. This study shows efforts to reduce the late effects of treatment are paying off," said study leader Dr. Gregory Armstrong. He's with St. Jude Children's Research Hospital's Department of Epidemiology and Cancer Control in Memphis, Tenn.

"The risk of second cancers for survivors increases with age, so it is good to see the reduction emerging early in survivorship while survivors are still young," Armstrong said in a hospital news release.

The study included information on more than 23,000 children, all five-year cancer survivors. The kids were treated at 27 different medical centers in the United States and Canada.

From the 1970s to the 1990s, the percentage of children treated with radiation for cancer fell from 77 percent to 33 percent. And the average dose of radiation used to treat children with cancer was also reduced.

For kids who survived cancer once, the risk of developing cancer again within 15 years also dropped, the researchers said.

The study was published online Feb. 28 in the Journal of the American Medical Association.

More information

The U.S. National Cancer Institute provides more information on childhood cancer.