Prognostic significance of tumor-enhancement and angiogenesis in oligodendroglioma

OBJECTIVE: To study the prognostic significance of angiogenesis and enhancement on contrast-enhanced computerized tomography (CT) in oligodendrogliomas. MATERIAL AND METHODS: CD34 immunostaining was employed in samples of 26 low-grade oligodendrogliomas from patients treated by extensive resection and radiotherapy to determine the tumor angiogenesis index (TAI), calculated by measuring the immunostained endothelial surface area, in microm(2), per 1000 tumor cells. Preoperative CT scan was evaluated in each case, and the absence or presence of tumor enhancement after contrast administration was recorded. Survival was analyzed and statistically compared for subgroups of patients with lesions in which the TAI was less than or greater than 15, and for subgroups of patients having tumors showing presence or absence of enhancement on contrast-enhanced CT. RESULTS: Survival of patients with tumors showing a TAI of less than 15 was 100% and 71% at 5 and 10 years, respectively, vs a survival of 50% and 0% for patients showing a TAI of more than 15 (P < 0.05). The 14 patients whose tumors showed enhancement in preoperative contrast-enhanced CT had 5- and 10-year survival rates of 57% and 14%, respectively, vs 100% and 83% for the 12 patients whose tumors presented no enhancement (P < 0.05). Moreover, 79% of the tumors showing contrast enhancement had a TAI greater than 15, while 92% of those exhibiting no enhancement had a TAI of less than 15. CONCLUSION: These findings indicate a relationship between enhancement on preoperative CT scan and endothelial surface area in oligodendrogliomas, and suggest that this enhancement and the TAI may be considered angiogenesis-related factors with similar prognostic significance in terms of survival.