Imbalance between apostain expression and proliferative index can predict survival in primary glioblastoma.
BACKGROUND
Cell proliferation and cell death are opposing processes in tumour growth, with tumour progression reflecting the balance between proliferating and apoptotic cells. The purpose of the present study is to verify the hypothesis that an imbalance between apoptosis and proliferation can predict survival in patients with primary glioblastoma.


METHODS
After the immunohistochemical study of Apostain and MIB-1 expression, the index of apoptosis (AI), the index of proliferation (PI), and the ratio AI/PI was recorded for each tumour specimen, in a series of 32 primary glioblastomas. Studies of correlation between AI and PI, between AI and survival, between PI and survival, and between the ratio AI/PI and survival, were performed using the Spearman rank correlation test. Furthermore, a comparative study of survival was performed for subgroups of patients with ratio AI/PI greater or lesser than 1, using the log rank test.


RESULTS
In the present series, values of AI and PI showed a wide distribution, with a mean +/- SD of 8.16 +/- 7.2, and of 12.69 +/- 21.1, respectively. The values for the ratio AI/PI ranged between 0.01 and 6.03 (mean +/- SD: 1.44 +/- 1.60). Statistical study failed to obtain correlation between AI and PI. Survival of patients not correlated with AI neither with PI. The ratio between AI and PI did not correlate with survival either. Nevertheless, when survival for the subgroups of patients showing a ratio AI/PI greater or lesser than 1 was compared, a significant difference was found (p: 0.02). Survival ranged between 50 and 81 weeks (mean of 58.5 +/- 11.05 weeks) for the 12 cases showing a ratio AI/PI greater than 1, and it ranged between 8 and 85 weeks (mean: 38.20 +/- 25.37 weeks) for the 20 cases showing a ratio AI/PI lesser than 1.


CONCLUSIONS
Our present results suggest that a clear imbalance between cell proliferation and apoptosis can predict outcome in patients operated on for a primary glioblastoma.
Vaquero
J
J
Laboratory of Experimental Neuro-oncology, Neuroscience Research Unit of the Mapfre Medicine Foundation, Puerta de Hierro Clinic, Autonomous University, Madrid, Spain.
Zurita
M
M
Coca
S
S
Oya
S
S
D000368:Aged; D017209:Apoptosis; D001932:Brain Neoplasms / Q000473:pathology*; D002455:Cell Division; D005260:Female; D005909:Glioblastoma / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D012680:Sensitivity and Specificity; D016019:Survival Analysis