Pilot study reveals the benefits of ‘whole genome sequencing’ for children with cancer

Doctor Patrick Tarpey. Credit: NCRI/Patrick Tarpey

Unraveling the complete genetic code for each child diagnosed with cancer could provide a more accurate diagnosis or reveal new treatment options, according to research presented at the NCRI festival. These are the results of a pilot study of the process known as whole genome sequencing.

The study also shows how whole genome sequencing, which is currently being rolled out for all childhood cancer patients in England, can be refined to provide maximum benefits to children with cancer.

The study was presented by Dr. Patrick Tarpey, Lead Scientist for Solid Cancer at the East Genomic Laboratory Hub, based at Cambridge University Hospitals NHS Foundation Trust, UK.

He said: “Full genome sequencing can sometimes unravel unexpected results that may not have been considered through routine research. We’ve already learned a lot about using this type of test in our pilot study, both in terms of the benefits for children and how you can evaluate the results.” optimize.”

The study, part of the 100,000 Genomes Project, included 36 children treated at Addenbrooke’s hospital in Cambridge and included 23 different types of solid tumors. For each child, a sample of their tumor and a sample of their blood was sent to a lab where the complete DNA sequence could be read. Scientists then looked for genetic differences, called variants, that could provide clues about how the cancer developed, the specific cancer type, and which treatments might be most effective.

This process revealed several potentially important variants. In two cases, the information refined children’s diagnosis and in four cases it changed their diagnosis. In eight cases, it revealed new information about children’s prognosis (the likely course of their illness). In two cases, it showed possible hereditary causes of the cancers. In seven cases, it revealed treatments that may not have been considered but were likely to be effective in treating the children.

For example, in one child, scientists found that two genes were stuck together (known as gene fusion), and this likely encouraged the tumor to grow. Knowing this meant doctors could offer another treatment called an MEK inhibitor, which would not normally be used to treat this type of cancer.

dr. Tarpey said: “Our results from this relatively small sample of children with cancer show how diagnosis and treatment can be improved. It suggests that providing full genome sequencing to all children with cancer will provide more accurate information about diagnosis and prognosis, showing whether there is a hereditary cancer risk and help inform treatment options.”

The pilot study also showed that some of the important variants were difficult to spot among all the data produced by whole genome sequencing. Their significance would have been missed without the careful analysis and interpretation of a panel of experts called a Genomic Tumor Advisory Board.

dr. Tarpey added: “As we scale whole genome sequencing to complement current standard care testing for children with cancer, we need to ensure that we optimize all steps in this process to reduce turnaround times and keep financial costs low.”

dr. Julia Chisholm is Chair of the NCRI’s Children’s Group, based at The Royal Marsden NHS Foundation Trust and The Institute of Cancer Research, London, UK, and was not involved in this research. She said: “Cancer is rare in children and thanks to research and better treatments, survival rates in the UK have doubled since the 1970s.

“This research shows that it is feasible and beneficial to analyze the entire genetic code in children with cancer. Whole genome sequencing helps us be more precise in the diagnosis of tumors and tailor treatments as closely as possible to individual patients. As this innovation is more widely introduced, we hope even more children will survive cancer.”

Comprehensive clinical sequencing opens the door to the promise of precision medicine

Provided by the National Cancer Research Institute

Quote: Pilot study reveals the benefits of ‘whole genome sequencing’ for children with cancer (2021, November 8), retrieved November 8, 2021 from https://medicalxpress.com/news/2021-11-reveals-benefits-genome-sequencing- children .html

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