a The tumor code is a random 2 letter code. Recurrent tumor from the same patient receives the same code with the addition of R. For each patient the primary and recurrent tumors were diagnosed by the same neuropathologist.
b Age in years at diagnosis of primary tumor.
c GBM = glioblastoma multiforme.
d BCNU = 1,3-bis(2-chloroethyl)-1-nitrosourea.
e NA = not applicable since this was a primary tumor.