Around 8.5 percent of children with cancer had mutations in genes such as BRCA1, BReast CAncer gene one and BRCA2, BReast CAncer gene two, which are known to cause breast and ovarian cancer in adulthood but have not been linked to childhood cancers before.
'More frequently than previously thought, children with cancer may have genes predisposing them to cancer, even when cancer doesn't show up in the child's family history,' said Dr John Maris, a paediatric oncologist at The Children's Hospital of Philadelphia, Pennsylvania, who wrote an editorial about the research for the New England Journal of Medicine.
The study itself was led by Dr James Downing at St Jude's Research Hospital in Memphis, Tennessee. His team examined the genes of 1120 cancer patients under the age of 20 for mutations in 60 genes that are associated with an increased risk of cancer. They found that 95 children – 8.5 percent – carried an inherited gene mutation that made them susceptible to the disease, compared with 1.1 percent in a control group of children.
Strikingly, less than half of these children had a family history of cancer, similar to the proportion in the general population.
Some of the most common mutations were in genes which are typically associated with adult-onset cancer, such as BRCA1, BRCA2 and APC, adenomatous polyposis coli gene.
'This kind of work helps in understanding where the tumors are coming from – and also what are some of the underlying driving mutations,' Dr Lisa Diller, Chief Medical Officer of Dana-Farber Boston Children's Cancer and Blood Disorders Center, who was not involved in the study, told Scientific American.
This discovery may help tailor treatments to specific patients, said Dr Downing. 'Knowing that a child has a mutation may change the way we treat that patient — the kind of chemotherapy we give, the kind of surgical approach we use, or the kind of radiation treatment that's given,' he told Time magazine.
In his editorial, Dr Maris argues that germline sequencing should be routinely incorporated into clinical care for young cancer patients. We don't yet understand all of this, he told Science. 'If a child happens to have a breast-cancer gene mutation, does that mean they're at risk for breast cancer later in life, or is that contributing to the child's cancer?'