The study shows how whole genome sequencing can benefit children with cancer

Disclosure of the entire genetic code for any child diagnosed with cancer could provide a more accurate diagnosis or open up new treatment options, according to a study presented at the NCRI festival. These are the results of a pilot study of a process known as sequencing of the entire genome.

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

The study was presented by Dr. Patrick Tarpy, a leading scientist for solid cancer at the Center for Eastern Genomic Laboratories, based at Cambridge University Hospitals of the NHS Foundation Trust, UK.

He said: “Sequencing of the entire genome can sometimes reveal unexpected results that may not have been taken into account through routine research. We have already learned a lot about the use of this type of test in our pilot study, both in terms of benefits for children and and in terms of how to optimize results. “

The study, part of the 100,000 Genome Project, included 36 children treated at Adenbrook Hospital in Cambridge and included 23 different types of solid tumors. For each child, a tumor sample and a blood sample were sent to a laboratory where the complete DNA sequence could be read. The researchers then looked for genetic differences, called variants, that could offer clues as to how the cancer developed, the specific type of cancer, and which treatments might be most effective.

This process revealed several potentially important options. In two cases the information specifies the diagnosis of the children, and in four cases it changes their diagnosis. In eight cases, she revealed new information about the prognosis of the children (the probable course of their disease). In two cases, he showed possible hereditary causes of cancer. In seven cases, he revealed treatments that may not have been considered, but are likely to be effective in treating children.

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

Our results from this relatively small pilot group of children with cancer show how diagnosis and treatment can be improved. This suggests that offering whole-genome sequencing to all children with cancer will provide more accurate information on diagnosis and prognosis, show if there may be any inherited cancer risk, and help inform treatment options. “

Dr. Patrick Tarpy, scientist

The pilot study also showed that some of the important variants are difficult to spot among all data obtained by sequencing the entire genome. Their significance could have been overlooked without the careful analysis and interpretation provided by an expert group called the Genomic Tumors Advisory Board.

Dr Tarpy added: “As we expand genome sequencing to complement current standard care tests for children with cancer, we need to ensure that we optimize all steps in this process to reduce execution time and reduce financial costs. .

Dr. Julia Chisholm is chair of the NCRI Children’s Group, based in The Royal Marsden NHS Foundation Trust and The Institute of Cancer Research, London, UK, and did not participate in this study. She said: “Cancer is rare in children and, thanks to research and better treatments, the survival rate in the UK has doubled since the 1970s.

“This study shows that it is possible and useful to analyze the entire genetic code in children diagnosed with cancer. The sequence of the whole genome helps us to be more precise in diagnosing tumors and to adapt the treatment to suit the individual patients as accurately as possible. As this innovation is introduced more widely, we hope that even more children will survive cancer. “


National Cancer Research Institute

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