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DIFFUSE INTRINSIC PONTINE GLIOMA:
COLLABORATION IS LEADING TO CHANGE

Dr Loice Swisher whose daughter Tori is a ten year medulloblastoma survivor. Loice is an FDA Patient Representative and emergency medicine physician. She is pictured here on a family vacation in Utah.

“It’s been almost two years since Sam was diagnosed in December 2006. The only improvement that I’ve seen during this time is that we have this wonderful site!” [the DIPG Internet Yahoo support list and discussion group]

So said “Sheila” (in December 2008), whose young grandson had died in February 2008 from a diffuse intrinsic pontine glioma.

A diffuse intrinsic pontine glioma, known as DIPG, is perhaps the most feared pediatric brain tumor because of the dismal survival statistics and devastating clinical course. This tumor tends to strike four to ten year olds with approximately half of these young children dying in the first year and 80-90% by the end of the second.

Despite more than 200 trials, no treatment has been found to be effective for long term survival in DIPG. For some children, steroids and radiation allow for a ‘honeymoon’ with relief of symptoms. But this is often followed by a relentless advancing of the disease and tragically, death months later.

Basic science research into this tumor has been frustratingly difficult. A significant hurdle has been the lack of tumor tissue on which to carry out tests.

In 1993, the standard of care for DIPG in the United States changed, as biopsy provided no improvement in survival over neuro-imaging in typical pediatric diffuse pontine tumors. Since that time, biopsies of pediatric DIPG have been uncommon resulting in the scarcity of tumor material for research. At the time “Sheila” wrote, there were no published reports on cell lines, no animal models and no molecular/genetic studies.

The changes in the medical community’s approach to a disease are often evident much before the patient community is aware of them because the time from concept to study to publication of a research paper can take years. In 2008, change was beginning in DIPG research. The heart-wrenching post from grandmother “Sheila” launched an effort towards earlier awareness of research endeavors as well as international advocacy collaboration.

In 2005 the biopsy debate had heated up again. St Jude Children’s Research Hospital in Memphis, Tennessee (USA) responded with a concerted effort to approach families for post-mortem tumor donation for research resulting in more molecular information on DIPG. Since many children die at home, far from St Jude, the emotional and logistical challenges were numerous.

A family responded to the financial issues raised by these challenges by establishing a foundation called Tyler’s Treehouse (established in 2006), specifically started to fund the logistical aspects of this study.

Over the ensuing years, many families with DIPG children have provided the ultimate gift to the research community involved with these studies of their child’s tumour tissue. Some families as far away as Australia and South America have donated their child’s tissue. The St. Jude efforts haven’t lead to publication yet, however, The Hospital for Sick Children (“Sick Kids”) in Toronto, Canada published the first whole genomic analysis of DIPG tumors in February 2010.

Their French colleagues took a different approach, with a clinical trial including upfront stereotactic biopsy of pediatric DIPG. In the July 2007 issue of the Journal of Neurosurgery the surgical results were published. With 33 children there was no mortality and only two children had transient morbidity.

The combined effect of the French stereotactic biopsy results and the molecular analysis studies from “Sick Kids” in Toronto has lead to renewed efforts for future clinical trials to include molecular analysis from stereotactic biopsy samples.

The development of animal models is also emerging.

At the 2008 ISPNO (International Symposium on Pediatric Neuro-Oncology) conference in Chicago (USA), Dr. Oren Becher won the best basic science presentation award for his genetically engineered mouse model of brainstem glioma. The excitement of potentially being able to study this tumor in a mouse model has resulted in requests for Dr Becher’s mice from several others interested in studying brainstem glioma.

For some time, the non-availability of resected tumor tissue for the development of cell lines has met with failure, even to the point of new researchers being discouraged from pursing this direction.

In the summer of 2009, Stanford University in California revealed that Dr. Michelle Monje had been able to culture neurospheres from post-mortem pediatric DIPG tissue using a stem cell technique. This breakthrough in DIPG research at Stanford has lead to an EGFRviii vaccine being introduced to the pediatric brain tumor community for the first time as well as other research. Some of this has been funded through the Kyle O’Connell Foundation.

Truly exciting events have been two international meetings of researchers and clinicians to discuss DIPG. The Fondo Alicia Pueyo hosted the first conference in Barcelona, Spain in February 2009. The second event was hosted by The Hospital for Sick Children in Toronto with funding support by Just One More Day and B.R.A.I.N.child.

We are now seeing a change in DIPG research – and the international collaboration of parents, advocates, clinicians and researchers that is making this happen.

 

Written by: Dr. Loice Swisher

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