Genetic testing of pediatric cancer patients allows researchers and physicians to better understand a child’s treatment options, chance of survival and hereditary cancer risk factors.
Unfortunately, precision medicine for childhood cancer has lagged behind its adult counterpart.Although pediatric cancers are the number one cause of death by disease in children and adolescents, they are considered rare because they account for less than 1% of all new cancer diagnoses in the United States each year.
For 2022, it was estimated that 1.9 million new cancer cases would be diagnosed, approximately 17,000 of which would be kids. Their rarity makes biologically characterizing pediatric cancers more difficult, which in turn negatively affects the development of precision therapeutics and the ability to test them via clinical trials.
Yet, the need for better therapies is arguably more important for children with cancer who, if they survive, have a much longer potential lifespan over which they must deal with the long-term side effects of generalized chemotherapy and radiation.
A new test
To accelerate precision medicine for pediatric oncology, Children’s Mercy Kansas City (CMKC), together with the Children’s Mercy Research Institute (CMRI), pioneered a new whole-exome-sequencing-based genetic test for all children diagnosed with cancer. This new test is run on both a tumor sample from the patient, plus a sample of their normal, healthy cells, so we can pinpoint genetic variants unique to the tumor (known as “somatic” variants), as well as the genetic variants underlying a patient’s hereditary risk for cancer (known as “germline” variants).
While many pediatric research institutions in the country conduct genetic sequencing of tumors, the CMRI is one of the few institutions performing both research and clinical sequencing in-house on both the tumor and normal DNA samples.
Understanding the variants that are specific to a certain kind of tumor and a patient’s genetics may help provide a more specific diagnosis of tumor type or subtype, inform risk of cancer development for other family members, give additional prognostic information to help predict survival, and finally allow physicians to explore more personalized treatment approaches that may be more effective. These personalized therapies tend to have fewer negative side effects as they target tumor cells specifically — unlike standard chemotherapies that kill both tumor cells and normal cells.
We are planning to use this test for every patient at CMKC who receives a new cancer diagnosis, as well as for those children whose cancer has relapsed. Sadly, these genetic tests are not always well covered by insurance, and patient families may be reluctant or unable to pay out-of-pocket for the test.
Through a framework provided by CMKC administration and philanthropic efforts, such as Big Slick, an annual celebrity fundraising event, this new genetic cancer testing is available to all patients without any out-of-pocket expense, which reflects the hospital’s commitment to diversity, equity, and inclusion, as well as high-quality patient care.
In addition, through the support of the CMRI and philanthropic partnerships, we are conducting research sequencing on pediatric cancer patients and openly sharing this genetic data with researchers worldwide as part of the National Cancer Institute’s Childhood Cancer Data Initiative. Data from the first 200 patients is already available.
Finally, for patients who were clinically tested but whose tumors lacked a genetic basis or “driver” for their disease, we are performing the most advanced sequencing — called 5-base long-read whole genome sequencing — to discover novel genetic causes of pediatric cancer. This effort is an extension of one of the CMRI’s flagship research projects, Genomics Answers for Kids, which looks for answers and new treatments for pediatric patients with rare inherited genetic conditions.