Researchers from the University of Colorado (CU) Cancer Center has found that the youngest patients with brain tumours - those ages from 0 to 3 months - have about half the five-year survival rate of children ages 1 to 19.

The study was published in the journal, Journal of Neuro-Oncology. Adam Green, MD, an associate professor of pediatric haematology/oncology at the CU School of Medicine, and his co-researchers analysed population-based data for almost 14,500 children ages 0 to 19 who were diagnosed with brain tumours. They found significantly poorer outcomes among the youngest patients.

"It's unusual to see infants or babies with brain tumours, but we do see them," Green explained. "We generally just don't have the same standards of treatment that we do for older children. We also know that infants can't report their own symptoms like older kids often can," he added.

Green and his co-researchers used data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program, a national cancer registry that covers more than a quarter of the U.S. population and represents the extensive diversity of the country.

The researchers extracted SEER data relating to childhood brain tumours and divided it into three age groups - 0 to 3 months, 3 to 6 months, and 6 to 12 months. They compared data in these three groups with brain tumour data in people ages 1 to 19.

What they discovered, Green said that "the types of brain tumours that babies get are different than in older patients, and that's an important finding in and of itself. The most important findings we had were that the survival that babies have from brain tumours is worse than older kids for almost all of the types of brain tumours we study."

Further data analysis showed that five-year survival in the 0 to 3 months age group is between 30 and 35 per cent, whereas five-year survival in the 1 to 19 age group is about 70 per cent. Five-year survival in the 3 to 6 month and 6 to 12 month age groups was also significantly lower than in older children.

This stark contrast in five-year survival rates "suggests that there may be just a lot of confusion and concern and reluctance in the pediatric neuro-oncology community to give these infants treatment or to perform surgery," Green says. "That may be a major cause of why these kids don't do as well. Also, they're more likely to present with metastatic disease when they do present with cancer, partly because they can't report their own symptoms so their diagnosis may be delayed."

"The youngest patients' tumours show different biology than tumours in older children and are often diagnosed in prenatal ultrasounds. Symptoms are different between age groups as well. Older children may present with headaches or vomiting, whereas "babies obviously aren't reporting headaches, but they may be inconsolably fussy over long periods of time or have a rapidly expanding head circumference that's off the growth charts," Green said.

"They may not be meeting developmental milestones or may have abnormalities in the way their eyes move. The symptoms may be more subtle and not typical of the usual brain tumour symptoms in older children," he added.

A particular challenge in treating the youngest patients with brain tumours is that though there are established standards of care and treatment for pediatric brain tumours, health care providers may be reluctant to use them on very young babies.

"We have radiation-sparing regimens that we use for children under 5, and we know those work well, but when it gets down to patients this young, it may be coming from the parents or from parents and medical teams thinking that it's going to be too toxic," Green explained.

"There may be a concern that patients this young are not going to tolerate surgery," he added. Green said that he hopes an immediate effect of the study is to inform the health care community of the decreased five-year survival rates for children younger than 1 who develop brain tumours. In turn, he hopes this awareness will lead to an increased willingness to apply standard-of-care therapies to the youngest patients with brain tumours.

"Taking the longer view, we still need to understand the biology of these tumours better," Green said. "We have some understanding now of how a certain type of brain tumour in an infant is different than that same type of brain tumour in an older child and we may need dedicated, specialised treatment protocols for these youngest children," he added.

Also, because many brain tumours in the youngest patients already are metastatic at diagnosis, "hopefully it will drive home the message in the general paediatrics community that there needs to be vigilance for this possibility," Green said.

"These tumours are rare, but primary care paediatricians and other folks in primary care need to be aware that these tumours can occur in infants. The biggest take-away is that these patients just aren't getting the treatment that would be considered standard in older kids," he concluded.