Child Cancer Patients are not Seeing the Full Benefits of Tumour Sequencing
51% of child cancer patients in a recent trial had gene mutations in their tumours that could be targeted by an existing adult cancer drug. However, due to clinical obstacles only 7% were able to receive the relevant drug, raising concerns about the lack of cancer therapies available for children.
Treating cancer in children is difficult, as many experience adverse effects from the chemotherapy drugs. However, the greater availability of tumour DNA sequencing has enabled the specific cancer-causing mutations in patient’s tumours to be identified, allowing patients to be assigned drugs that directly target these mutations. Although this approach has transformed the treatment of cancer for adult patients, child patients have yet to see the full benefit of tumour sequencing. A recent study aimed to identify if tumour sequencing could also lead to more effective treatment for child cancer patients.
A selection of 91 genes that control cancer growth were searched for in the tumour DNA of 223 child cancer patients. 51% of the children had genes expressed in their tumours that could be targeted by an existing adult cancer therapy. For example, three children had tumours with mutations in the BRAF gene, enabling their tumours to be treated with an existing melanoma drug that targets the BRAF mutation.
However, only 7% of the children with targetable mutations were able to undergo treatment with the relevant drug. Many drugs had not been tested on children so were unable to be used due to safety concerns and some relevant clinical trials did not accept paediatric patients. Several other drugs were too costly to be available through the NHS and some children became too ill to receive treatment after being tested. The children that were able to be treated by adult drugs generally had good responses and displayed either slower or no disease progression whilst on treatment.
More research is therefore needed to ensure that existing cancer treatments for adults are also made safe and available for children.
At the World Metastasis Summit, taking place in Boston this November, Bruce Zetter, Professor of Cancer Biology at Harvard University will be discussing A Method to Select Drug Candidates that Target Late-stage Tumors. You can view the full agenda here.