"Why does my child have cancer?": Inside the world of cancer genetic counselling at SickKids

Why does my child have cancer?

Bailey Gallinger’s job is to help families navigate the answer to that difficult, pressing question. In her 10 years at The Hospital for Sick Children (SickKids), she has learned that there’s real value in the education she gives patients and families. Understandably, most haven’t heard of cancer genetics before their diagnosis.

“It’s usually something they don’t need to know until they are faced with it,” says Gallinger, a genetic counsellor in SickKids’ Cancer Genetics Program.

“I do feel like pretty much every patient and family I see, at least I’ve taught them something or provided more information that the family didn’t get elsewhere. I can help guide them to try to figure out maybe why this happened. We don’t always get an answer, but sometimes that’s an answer in itself.”

Finding a cause 

Most cancers are sporadic, Gallinger explains, meaning sometimes it’s impossible to know why one child has cancer and another doesn’t.

But there is a subset of paediatric patients with cancer, at least 15 per cent of those treated at SickKids, who have a higher risk of developing cancer at an earlier age compared to the risk for the general population because they have a cancer predisposition syndrome caused by a genetic mutation in their DNA or genes.

Gallinger’s role is to try to figure out which category a patient falls into: Is their cancer caused by chance, or the result of a cancer predisposition syndrome? 

“That’s super important for families to know,” she says. “It can have a lot of implications.” 

If a child’s cancer is found to be caused by a cancer predisposition syndrome, Gallinger helps the family understand what that means and organize testing for other family members like the patient’s parents and siblings. Anyone else found to have the same syndrome is also monitored closely through surveillance protocols and the child is also followed with increased surveillance both during and after their treatment ends to look for new tumours. 

“Unfortunately, we can't at this point change someone's DNA, so currently we can't necessarily stop a cancer from starting,” Gallinger says.  

But genetic testing does allow for better prediction of cancer – and earlier treatment that can lead to better outcomes, all of which are at the core of SickKids’ Precision Child Health movement. If oncologists know someone has a higher risk of developing a certain type of tumour in a certain part of their body, they can use regular imaging – including MRIs, ultrasounds, CT scans, physical examinations and blood work – to try to catch and treat any developments early. That way, the patient may be able to have surgery to remove a small tumour, potentially sparing them from chemo and radiation.  

“If we can catch something early from a surveillance protocol, we know that studies show that these patients do much better than if they present to us with a big tumour or one that has already spread to other parts of the body,” Gallinger says.  

Emotional, rewarding work

In the near future, genetic testing for all children with cancer at SickKids will likely become a reality. Currently, Gallinger doesn’t see every patient with cancer at SickKids. She sees patients at higher risk of having a cancer predisposition syndrome, such as those with specific tumour types or a family history suggestive of a cancer predisposition syndrome.

She also organizes testing for patients who don’t have cancer, but whose parents or sibling have been diagnosed with a cancer predisposition syndrome, as their first-degree relatives have a 50 per cent chance of inheriting the genetic mutation that causes the syndrome.

It can be stressful for families to hear that other children might also be at risk for cancer if one has already been diagnosed, so Gallinger notes the timing of these conversations is important. So much happens with a new diagnosis, she says, and she wants to avoid further overwhelming families right at the beginning of their journey. 

Friends sometimes say to her, “Working in childhood cancer must be so sad.” It can be, Gallinger says, but she’s encouraged by the positive outcomes many children and youth have.  

She finds it rewarding to see younger patients who have a cancer predisposition syndrome grow up and become more involved in the process of understanding their own DNA and health through their regular check-ins, which continue after their treatment ends and they transition out of SickKids after their 18th birthday.  

Gallinger has also found it gratifying to see how her own skills have developed over the years in counselling patients of different ages, from young children with their families to adolescents. By tailoring her counselling approach to each patient and family, she provides families with the guidance and resources to find support and make decisions that are aligned with their individual needs, values and beliefs.  

“I think a lot of families realize they’re way stronger than they even realize when they are faced with something like this,” Gallinger says. “So it’s a privilege and honour to work with them in such a high-stress time.”