Long-term glioblastoma multiforme survivors: a population-based study.
BACKGROUND
Long-term glioblastoma multiforme survivors (LTGBMS) are uncommon. The frequency which these occur in an unselected population and factors which produce these unusually long survivors are unknown.


OBJECTIVE
To determine in a population-based study 1) the frequency of LTGBMS in a population and 2) identify which patient, treatment or tumor characteristics would predict which glioblastoma (GBM) patient would become a LTGBMS.


METHODS
The Alberta Cancer Registry was used to identify all patients diagnosed with GBM in southern Alberta between 1/1/75-12/31/91. Patient charts were reviewed and histology re-examined by a blinded neuropathologist. LTGBMS were defined as GBM patients surviving > or = 3 years after diagnosis. Each LTGBMS was compared to three age-, gender-, and year of diagnosis-matched controls to compare patient, treatment, and tumor factors to GBM patients without long-term survival.


RESULTS
There were 279 GBMs diagnosed in the study period. Five (1.8%) survived > or = three years (range, 3.2-15.8 years). Seven additional long-term survivors, who carried a diagnosis of GBM, were excluded after neuropathologic review; the most common revised diagnosis was malignant oligodendroglioma. LTGBMS (avg. age = 45 years) were significantly younger when compared to all GBM patients (avg. age = 59 years, p = 0.0001) diagnosed in the study period. LTGBMS had a higher KPS at diagnosis (p = 0.001) compared to controls. Tumors from LTGBMS tended to have fewer mitoses and a lower Ki-67 cellular proliferative index compared to controls. Radiation-induced dementia was common and disabling in LTGBMS.


CONCLUSIONS
These data highlight the dismal prognosis for GBM patients who have both a short median survival and very small chance (1.8%) of long-term survival. The LTGBMS were younger, had a higher performance status, and their tumors tended to proliferate less rapidly than control GBM patients. When long-term survival does occur it is often accompanied by severe treatment-induced dementia.
Department of Clinical Neurosciences, University of Calgary.
J N
JN
Scott
N B
NB
Rewcastle
P M
PM
Brasher
D
D
Fulton
N A
NA
Hagen
J A
JA
MacKinnon
G
G
Sutherland
J G
JG
Cairncross
P
P
Forsyth
D000328:Adult; D000416:Alberta / Q000453:epidemiology; D001921:Brain / Q000473:pathology; D001932:Brain Neoplasms / Q000453:epidemiology* / Q000473:pathology; D005260:Female; D005909:Glioblastoma / Q000453:epidemiology* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008938:Mitosis / Q000502:physiology; D011153:Population; D017741:Survivors