Children over the age of 10 who are being treated for cancer appear to be at a significantly increased risk of bone osteonecrosis compared to younger children, an expert says.
Speaking at the Australian and New Zealand Bone and Mineral Society annual scientific congress held on the Gold Coast earlier this month paediatric endocrinologist Craig Munns from the Children’s Hospital at Westmead, Sydney, told conference delegates there was a compelling case for screening older children for bone lesions – the hallmark of osteonecrosis.
“Children over the age of 10 [and adults] are more likely to get osteonecrosis and that’s a predictor of joint collapse, which can lead to the need for joint replacement,” he said.
According to Professor Munns research had shown that in childhood acute lymphoblastic leukaemia (ALL) symptomatic osteonecrosis occurred in about 17 percent of children, 83% of whom had the disease within the first year of treatment. The same study revealed asymptomatic disease in over half of the children.
Another study looking at the cumulative incidence of osteonecrosis showed that the bone disease occurred in half of children over 10 years of age, compared to an incidence of 15 percent in children aged less than 10 years.
Furthermore, 50% percent of the hips of children aged less than 10 years showed improvement, something not seen in the children aged over 10.
Professor Munn said data from his centre also followed the same pattern.
“There’s this real line in the sand as far as children are concerned,” he told delegates.
During question time following the presentation Professor Emma Duncan, a Senior Staff Specialist in Endocrinology at Royal Brisbane and Women’s Hospital, asked Professor Munn what happened at the age of 10 that caused the increased risk.
“What’s the trigger, is it puberty?” she asked.
Professor Munns said potential factors at play could be weight, pubertal hormones, or something inherently different.
“Younger children heal better than older children so I think it is something more inherent with the fact that you’re growing up… but we don’t know,” he said.
MRI tells a better story
Current recommendations state that patients suspected of having osteonecrosis should first have an x-ray to detect bone lesions, Professor Munn told delegates.
“If [the x-ray] is negative then you can do an MRI, however if you do an x-ray and it is positive but you’re unsure of the size of the lesion then an MRI is recommended,” Associate Professor Munns said.
“If there is significant changes on the x-ray the current recommendation is not to do an MRI…however an MRI gives you a really good idea of what’s going on and the extent of the lesion”.
“So even though these are the recommendations I think we have to think beyond that – is there a better way of getting an idea of what’s going on?” he said.