Researchers from Newcastle University (UK) and The Institute of Cancer Research (London, UK) have identified the unique genetic pathways that lead to childhood medulloblastoma relapse. The findings of the study were published in Cancer Cell.
The survival rate for children with medulloblastoma is 60–70% but for those patients who relapse this reduces to >5%. The study shows that taking an additional tumor sample at recurrence may identify patients that could be treated with existing drugs that target genetic faults.
The researchers collected relapsed tumor biopsies from 29 patients and identified a variety of changes that were associated with the return of the cancer in a more aggressive form. In particular, a specific combination of two genetic changes was found to be associated with a number of different subtypes, which account for a very aggressive form of the disease.
Further to this, the researchers investigated drug treatments for relapsed medulloblastomas in mice. They were able to slow the growth of the tumor with an experimental drug that targets one of the faults.
Louis Chesler from The Institute of Cancer Research commented: “We were very pleased to show in our study that some children with relapsed medulloblastoma could benefit from currently available targeted drugs, which usually have fewer and less severe side effects than traditional chemotherapy. It gives us a recipe to direct the use of targeted medicines in relapse where they are most needed.”
Chesler also added: “To personalize treatment to those who might benefit, doctors will need access to tumor samples as soon as children develop relapsed disease. Tumor biopsies are not routinely taken in these situations currently – and that will have to change before we can match the best treatments to the children who desperately need them,”
Steve Clifford (Newcastle University), joint lead researcher of the study, commented: “Our study shows that we need to understand and treat relapsed medulloblastoma in a completely new way. It’s clear that new biopsies need to be taken when the disease returns to give doctors a clearer picture of the best and most appropriate treatment.”
Peter Johnson, Cancer Research UK’s chief clinician, explained: “We urgently need new treatments that are effective in relapsed medulloblastoma – there are too few effective options that doctors can use. We’re learning more all the time about how cancers evolve and change – in the short term this work will mean that doctors can decide on the most appropriate palliative care options for medulloblastoma but more importantly the research will lead to better treatments in the future.”