Prognostic Significance of p53 and p21WAF1/CIP1 Immunoreactivity and Tumor Micronecrosis for Recurrence of Meningiomas

Recurrence is an important factor for prognosis of meningioma patients, this also occurring with some lesions diagnosed histopathologically as benign. To analyze their relationships with clinicopathological factors, p53 and p21^WAF1/CIP1 immunoreactivity, 80 meningiomas were classified into four groups with regard to the World Health Organization (WHO) histological classification and recurrence: 40 cases of Group I (typical type)-NR (no recurrence); five cases of Group I-R (recurrence); 20 cases of Group II (atypical or anaplastic type)-NR and 15 cases of Group II-R.Micronecrosis was detected in 25% of Group II-NR and 73.3% of Group II-R (P=0.007, odds ratio (OR) =8.25, 95% confidence interval (CI) =1.79–38.01). Patients receiving radiation therapy had a lower risk of recurrence (P=0.041, OR =0.20, 95% CI =0.05–0.85). Immunoreactivity for p53 protein was positive in 22% of Group I and 54% or Group II (P=0.005), and in 80% of Group I-R and 15% of Group I-NR (P=0.006, OR = 22.7, 95% CI = 2.15–239.4). p21^WAF1/CIP1 protein was detected in 22% of Group I and 48% of Group II (P=0.017), but with no link to recurrence. Multivariate analysis also showed p53 immunoreactivity in Group I (benign lesions) and micronecrosis in Group II (atypical/anaplastic meningiomas) to be strong prognostic factors for recurrence (P<0.05). These results indicate that p53 immunoreactivity and micronecrosis can help predicting recurrence of meningiomas.