Childhood cancer survivors found to be at higher risk of mental illness

Most children with cancer in Canada now survive. But they're at greater risk of poor mental health outcomes, such as anxiety and substance abuse, according to a Canadian oncologist who was surprised at the extent of severe issues.

About 80 per cent of children with cancer will achieve a long-term cure. Yet childhood cancer survivors may be vulnerable to long-term physical effects that can be severe. Less is known about impacts on mental health.

In Thursday's issue of the journal Cancer, researchers analyzed data from about 4,000 childhood cancer survivors in Ontario as well as 20,000 others in the general population to compare health care use. The findings have implications for mental health supports and parenting those who have survived cancer. 

Among cancer survivors who were four years and younger when they were diagnosed, 131 had a severe event during the follow-up period of the study. 

By age 28, the cumulative incidence of a severe event such as hospitalization or visit to an emergency department for a mental health reason among this group was more than 16 per cent. 

"That really surprised us," said Dr. Sumit Gupta, a co-author of the study and a staff oncologist Toronto's Hospital for Sick Children.

The most frequent mental health issues included anxiety, substance abuse and mood disorders. 

The researchers also found that childhood cancer survivors had a 34 per cent higher rate of medical visits for a mental health complaint compared to the general population.

Gupta and his team looked at some of the treatments children with cancer receive at a young age to see if the drugs triggered a reaction. The type of chemotherapy didn't pan out as an explanation.

Instead, it seems like something about the experience of enduring cancer when young increases the risk of long-term mental health problems, he said.

Challenge to turn off hypervigilance 

The data itself doesn't provide many clues. But Gupta speculates that being labelled as a child cancer survivor could contribute.

If so, one of the implications is for parents.

"You can imagine that if you're a parent and your kid gets diagnosed with cancer and you go through months and maybe even years of watching your kid like a hawk for any complications of treatment and your whole life … becomes 100 per cent focused on making sure that your kid is OK and you basically become hyper vigilant, appropriately so, for all that time," Gupta said in an interview.

"And then when your kids survives, then we ask parents to do maybe an equally hard task, which is to turn that hyper vigilance off. "

Gupta, a clinician investigator at Sick Kids who treats children with leukemia and lymphoma, gave an example: "I had a mother once tell me that coming off of treatment was in a very strange way just as hard as going on to treatment."

'Like a room with the lights out'

The findings make sense to Geoff Eaton of St. John's. Eaton, 42, had acute leukemia twice in his twenties.

"It takes longer to recover from cancer than to be treated for it," said Eaton, founder and executive director of Young Adult Cancer Canada, which supports young adults.

For decades and to this day, the majority of resources are for cancer treatment, which Eaton acknowledges is important.

"But we have focused so heavily on treatment that we almost entirely neglected the rest of the patient's life," he said. "The rest of a patient's life is like a room with the lights out. We don't even know what's in there. There's been such little investigation and study into that."

Gupta wants cancer survivors, their families and health-care providers to be aware of the mental health risk, just as they are attuned to long-term physical health effects of surviving cancer, such as cardiac health.

"We still have a lot of stigma toward mental health in our society," Gupta said. "I think making survivors and families aware of this potential and encouraging them that if they are feeling distress or significant anxiety or significant depression or any other mental health issue that maybe isn't unexpected and they should seek help … instead of trying to struggle with it with their own."

The subjects in the study were diagnosed before age 18 and treated between 1987 and 2008.