Microscopic thrombi in anaplastic astrocytoma predict worse survival?

The purpose of this study is to determine whether anaplastic astrocytoma patients with intratumoral vascular thrombi have a worse survival than anaplastic astrocytoma patients without thrombi. A retrospective review of 101 patients (60 males; mean age, 53.3 years) with anaplastic astrocytoma (World Health Organization grade III) was conducted. Thrombi were counted relative to the number of involved blood vessels in the initially resected tumor (69 biopsies, 32 subtotal resections) and were correlated with survival and development of postoperative deep venous thrombosis (DVT). Of tumors with thrombi (n = 17), the percentage of blood vessels with thrombi ranged from 1.5% to 20% (mean, 5.6%). Of these patients, 16 died of tumor (mean survival, 15.4 months), and 1 patient was alive with tumor at 180 months. Eighty-four patients with anaplastic astrocytoma had no intravascular tumor thrombi; 75 of these patients died of tumor (mean survival, 26.5 months), 4 patients were alive, and 5 patients were lost to follow-up. Evidence of DVT was found in 2 (18.2%) of 11 tested patients with thrombi vs 10 (18.5%) of 54 patients without thrombi. Patients with microscopic intratumoral thrombi (17% of anaplastic astrocytoma) had a worse survival compared with patients without thrombi; the difference did not reach statistical significance. There was no correlation between the presence of intratumoral thrombi and the development of DVT.