MONDAY, July 9, 2007 (HealthDay News) -- Cancer tends to grow faster in children than in adults, but a new study finds there's scant evidence on how delays in diagnosis might affect outcomes.
What research there is suggests that some kinds of tumors are more likely to be missed for longer periods of time, however.
Researchers could only find 23 studies focused on the effects of diagnosis delays for pediatric cancer, and they don't make it clear whether serious shortcomings exist, said report co-author Eduardo Franco.
"They led to conflicting interpretations in terms of what would have an impact," said Franco, a professor in the departments of oncology and epidemiology at McGill University in Montreal. "The research needs to be more focused."
Cancer in children is rare, affecting about 10,000 kids in the United States each year. While death rates have gone down, pediatric malignancies are especially dangerous, because tumors grow more rapidly than in adults.
Launching the first review of its kind, Franco and a colleague examined existing research to figure out what causes delays in diagnosis and how they may affect the health of children with cancer. Since tumors worsen over time, a prompt diagnosis can be crucial.
The findings are to be published in the Aug. 15 issue of Cancer.
The authors found 23 studies from around the world, which Franco called a fairly small number. There's much more interest in the impact of diagnosis delays on adults, he said, adding that delays in breast cancer diagnoses alone might spawn 23 studies a year.
While they weren't conclusive, the studies suggested that it takes longer for doctors to diagnose brain and eye tumors, which are both rare. However, many of the studies looked at those types of tumors specifically, so comparison to other types of cancer is difficult.
The studies also suggested that it generally takes longer for doctors to diagnose disease than it does for patients or their families to figure out that there's a problem in the first place.
According to the review, the research as a whole suggested delays could be related to other factors, such as health-care systems that don't allow patients to see specialists without permission.
The challenge for researchers is to figure out how much of diagnosis delays are "part of the natural, regular process of troubleshooting and conducting diagnosis," Franco said. "There is a point where we should say, 'It's no longer a concern of the parents, they've done their part.' From that time onwards, it's a responsibility of the health-care system."
How bad were the diagnosis delays? The studies suggested they weren't major, Franco said, but the research was mostly on teaching hospitals and didn't provide a larger look at all kinds of facilities.
Dr. Daniel Wechsler, chief of pediatric hematology-oncology at Duke University Medical Center, said it's difficult to derive any conclusions from the studies examined in the new review, because they're "from a wide range of countries and cover a wide range of diagnoses."
Better education of pediatricians and family practitioners could possibly help quicken diagnosis of eye tumors, Wechsler said. But they only make up about 1 percent of childhood tumors.
There are sometimes delays in diagnosis of brain and bone tumors, he said, but "for the vast majority of other pediatric tumors, delays are not really a problem."
According to Franco, the next step in research is to launch larger studies that examine factors such as health-care systems (the Canadian system vs. that in the United States, for example) and to look at various types of hospitals.
There's more on childhood cancers at the U.S. National Cancer Institute.