Potential to Reduce Children’s Side-effects
29 March 2010 - Some children with rhabdomyosarcoma could be given less intensive treatment than current practice to reduce their risk of damaging side-effects.
Treatment for this childhood cancer is presently based on whether a patient’s cancer is classified as alveolar or embryonal, which is determined by the appearance of a tumour sample under the microscope. Alveolar rhabdomyosarcoma is considered more aggressive, so these patients are given a more intense combination of chemotherapy, radiotherapy and sometimes surgery.
ICR scientists have now found a genetic test that can identify patients with a less aggressive form of alveolar rhabdomyosarcoma, who may be able to avoid such intense treatment and the correspondingly higher risk of side-effects.
The team examined samples from 210 rhabdomyosarcoma patients and identified 39 cancers that looked like aggressive alveolar type but behaved more like the milder embryonal type. This group of patients had less cancer spread and higher survival rates. Genetic testing revealed that the cancers from these patients lacked a genetic abnormality, known as a PAX/FOX01 fusion gene, which has previously been linked to the alveolar subtype.
Subsequent analysis of thousands of genes confirmed alveolar rhabdomyosarcomas without a fusion gene are biologically similar to the embryonal subtype but very different from alveolar cancers with a fusion gene.
“We have shown that presence of a fusion gene – not tumour appearance – is a key factor in predicting cancer aggressiveness,” Dr Janet Shipley says. “This study should lead to a re-think in the management of children with the fusion gene-negative alveolar cancer in order to minimise side-effects for these patients.”
