Prognostic significance of annexin VII expression in glioblastomas multiforme in humans

Glioblastoma multiforme (GBM) is the most common and lethal primary brain tumor in adults. It is nearly uniformly fatal, with a median survival time of approximately 1 year, despite modem treatment modalities. Nevertheless, a range of survival times exists around this median. Efforts to understand why some patients live longer or shorter than the average may provide insight into the biology of these neoplasms. The annexin VII (ANX7) gene is located on the human chromosome 10q21, a site long hypothesized to harbor tumor suppressor genes associated with prostate and other cancers. To test whether ANX7 expression might be a predictor for GBMs, we examined ANX7 expression, p53 accumulation, and the MIB-1 labeling index in a retrospective series of 99 GBMs.

In all 99 cases, the patient's age, Karnofsky Performance Scale (KPS) score before surgery, extent of surgery, tumor location, and immunohistochemical features were analyzed using univariate and multivariate analyses to identify whether any significance exists among ANX7 expression, p53 accumulation, the MIB-1 labeling index, and survival time. Kaplan-Meier analyses demonstrated that a higher KPS score before surgery (< 0.0001), total tumor excision (p = 0.0072), young patient age (p = 0.03), and ANX7 expression (p = 0.0006) correlated with longer survival. Multivariate Cox regression analyses demonstrated that ANX7 expression was the strongest predictor of outcome (p < 0.0001), independent of all other variables. In addition, ANX7 expression correlated with higher MIB-1 immunostaining, but did not correlate with p53 accumulation. Moreover, a significant positive correlation was observed between p53 and MIB-1 staining.

These findings indicate that a higher KPS score before surgery, total tumor excision, young patient age, and ANX7 expression correlate with longer survival in patients with GBMs. Multivariate Cox regression analyses demonstrated that ANX7 expression was the strongest predictor of outcome (p < 0.0001) and was independent of all other variables.