The prognostic value of tumor markers in patients with glioblastoma multiforme: analysis of 32 patients and review of the literature

Although several studies have examined brain tumor markers for prognostic value, few investigations have stratified analysis based on specific histologic grade. The objective of this study was to evaluate a single histologic grade of glioma, the grade IV glioma or glioblastoma (World Health Organization Classification), with a comprehensive panel of tumor markers in an attempt to identify those with prognostic significance. Tumor samples from a cohort of patients with glioblastoma multiforme (n = 32) were examined for tumor markers, DNA analysis, and clinical variables in an attempt to determine a 'profile' for this tumor. We used univariate and multivariate statistical analysis to determine the prognostic value of tumor cell ploidy, percent S-phase, DNA index, p53, and Ki-67 labeling index, as well as the variables of gender, race, age, location of tumor, history of chemotherapy, and primary versus recurrent tumor. Two additional tumor markers, multidrug resistance gene 1 and glutathione-S-transferase subtype pi, were included in the sample testing, but were not analyzed statistically. Univariate analysis indicated that increasing age had a strong association with decreased survival. Female gender, increasing Ki-67, no chemotherapy before sample collection, and primary glioblastoma showed some association with decreased survival in the univariate model. The univariate results indicated that race, side of tumor, ploidy, S-phase, DNA index, and p53 had no prognostic value. Multivariate modeling demonstrated that age, gender, and Ki-67 were the strongest factors associated with survival. The relevant literature is reviewed.