Abstract
A 10 year old presented in 2014 with left sided weakness and numbness and was found to have a large infiltrating mass involving the right perisylvian frontal and temporal cortex and causing mass effect. It was biopsied and shown to be an anaplastic oligodendroglioma (WHO Grade III) with no LOH 1p19q. The patient underwent 60 Gy cranial radiation with temozolomide and the MRI following radiation showed the mass had progressed with increased enhancement. The patient was then started on maintenance temozolomide, bevacizumab, and irinotecan but 7 months later further progressed. The patient was switched to procarbazine, lomustine and vincristine (PCV) but after 4 months showed further progression. Patient was wheel chair bound and was made do not resuscitate. Foundation One testing was sent and revealed mutations in EGFR, a receptor tyrosine kinase, and FBXW7, a member of the SCF complex predicted to sensitize cells to rapamycin. As a consequence, the patient was started on erlotinib, an EGFR inhibitor, and rapamycin, a mTOR inhibitor. The patient showed immediate response and tumor regression and continues to remain on these medications with sustained response for 2.5 years. Immunofluorescent analyses of fixed tumor specimens indicates that EGFR-positive cells in the pre-treatment tumor frequently also exhibit high levels of p-S6, an indicator of mTOR activity, suggesting that a majority of cells within this tumor may be targeted by both inhibitors simultaneously, rather than two independent populations being present. This regimen has potential to be an effective regimen in those with similar mutations.