There's been a sharp decline in the number of U.S. children taking part in cancer clinical trials over the past few decades, but researchers say that might be good news.
Why? Having more effective treatments available now may be one reason for that decrease, they explained.
The researchers, from the University of Colorado Cancer Center, analyzed national data and found that pediatric oncology clinical trial enrollment fell from 40-70% in the 1990s, to 20-25% in the early 2000s, and to 19.9% currently.
Historically, pediatric cancer patients have been much more likely than adult cancer patients to enroll in clinical trials as part of their treatment, according to the authors.
"Childhood cancer is rare overall, so historically high enrollment rates to clinical trials has been integral to improving outcomes for our patients," explained study first author Dr. Kelly Faulk, cancer center investigator and pediatric oncologist at Children's Hospital Colorado.
"The potential reduction in enrollment isn't all bad news," Faulk added in a university news release. "One reason trial enrollment may be decreasing is that good treatments have been developed for some of the most common childhood cancers, thereby shifting the focus and resources toward opening trials for higher-risk, but often more rare, cancers."
Also, childhood cancers tend to have fewer mutations than adult cancers, so they provide fewer genetic targets for the kinds of new drugs being tested in many clinical trials, Faulk noted.
But a less positive factor is a lack of funding for childhood cancer research, which limits the number of new clinical trials.
Faulk and her colleagues found no significant racial, ethnic or socioeconomic disparities within childhood cancer clinical trial enrollment, unlike many adult clinical trials.
However, this study did find that teens and young adults are under-enrolled in cancer clinical trials.
"They can feel lost between pediatric and adult cancer care, and unfortunately these [teen and young adult] patients represent a population that has failed to see the same improvements in outcomes that their younger counterparts have," Faulk said.
"Given their age and other socioeconomic factors, they may not see doctors as often and commonly suffer from suboptimal health insurance coverage," she said.
The study was published online recently in the journal PLOS One.
The American Cancer Society has more about cancer in children.