EXPRESSION OF THE NEUROTROPHIN RECEPTOR TRKC IS LINKED TO A FAVORABLEOUTCOME IN MEDULLOBLASTOMA

Medulloblastoma, the most common malignant brain tumor of childhood, h as a variable prognosis. Although half of the children and young adult s with the disease survive longer than 10 years after diagnosis, the o thers relapse and die despite identical therapy. We have examined the expression of neurotrophins and their receptors in medulloblastoma bla stoma samples snap frozen in the operating room to preserve RNA integr ity. All tumors (n = 12) were found to express mRNA encoding neurotrop hin 3 and its receptor TrkC. The level of trkC expression was highly v ariable, with a more than 50-fold difference between the highest and l owest values. By Kaplan-Meier analysis, patients with tumors expressin g high levels of trkC mRNA had significantly longer intervals without disease progression than those with low levels (log-rank, P = 0.03) an d a more favorable overall survival (log-rank, P = 0.05). Thus, trkC e xpression is a prognostic indicator for patients with medulloblastoma.