Tibial nerve tumor in a 72-year-old man

We read with great interest the recent articles of Buttarelli et al. [1] and Srivastava et al. [2] on MGMT status in pediatric high-grade gliomas. The authors observed MGMT promoter methylation in 7/24 (30%) and 10/20 (50%) of the tumors, respectively. In adults, MGMT promoter methylation is the most promising prognostic marker to predict patients' outcome and it has been observed in the 30–40% of the cases. On the other hand, only sporadic information are available regarding pediatric cases. In their seminal work, Donson and colleagues [3] observed four of ten (40%) GBM pediatric patients with methylation of the MGMT gene promoter and that the methylated cases were associated with an improved survival time. Moreover, MGMT down-regulation was associated with a good response to temozolomide therapy. Recently, Schlosser and colleagues demonstrated promoter methylation in 77% of pediatric high-grade gliomas [4]. To further investigate the role of MGMT promoter methylation status in this specific group of tumors, we retrospectively surveyed a series of ten pediatric patients surgically treated from January 2001 to September 2008, at the Department of Pediatrics (Pediatric Neurosurgery Unit) of the University Hospital of Padova (seven grade IV and three grade III gliomas). Patients included five males and five females with a mean age of 12.3 years (median 11.5 years) at diagnosis. In five cases, the surgical excision of the tumor mass was partial, in two cases sub-total and in three cases complete. All patients received post-operative chemotherapy with temozolomide (in seven cases combined with other alkylating agents) and radiation therapy. Overall, all patients suffered relapse or progression of the disease: three patients are still alive, whereas seven died. MGMT status assessment was performed as previously described [5], and no case of MGMT promoter methylation has been detected. This divergent data underlines the fact that we are still far from a well-defined characterization of pediatric cases. Further larger and multi-Institutional studies should investigate and validate the significant role of MGMT promoter methylation status assessment as a potential prognostic factor in pediatric high-grade gliomas, as well as to design different trials and treatment strategies for patients with unmethylated MGMT promoter.