Combined treatment modality for anaplastic oligodendroglioma: A phase II study

Purpose: To investigate feasibility, toxicity and antitumor activity of com bined surgery, postoperative radiation therapy (RT) and adjuvant chemothera py (CHT) in adult patients with pure anaplastic oligodendroglioma (PAO) or mixed anaplastic oligoastrocytoma (MAO). Methods: Between January 1988, and June 1993, 23 patients entered into a ph ase II study. After surgery, post-operative RT was administered with 60 Gy in 30 daily fractions in 30 treatment days in 6 weeks. Two weeks after RT, adjuvant 'modified' PCV (mPCV) (Procarbazine, 60 mg/m(2), days 1-14; CCNU, 100 mg/m(2), day 1; and vincristine, 1.4 mg/m(2) (max. 2 mg), days 1 and 8) was administered every six weeks up to six cycles or until progression occ urred. Results: Median survival time is not attained yet, while 1-5 year survival rates are 100%, 100%, 78%, 61%, and 52%, respectively. Median time to tumor progression is not attained yet, while 1-5 year progression-free survival rates are 100%, 100%, 70%, 52%, and 52%, respectively. On univariate analys is of potential prognostic factors, sex, tumor location (frontal versus oth er), and histology (pure versus mixed anaplastic oligodendroglioma) were no t found to influence survival. Age of < 50 years carried improved prognosis as well as Karnofsky performance status (KPS) 90-100 when compared to KPS of 70-80. Patients having tumors less than or equal to 4 cm did better than those with tumors > 4 cm as well as those with total tumor resection when compared to those with subtotal tumor resection or biopsy only. Acute high- grade (greater than or equal to 3) CHT-related toxicity was mainly hematolo gical with only 3 (13%) patients experiencing acute grade 4 toxicity. Conclusions: Combined treatment modality consisting of surgery, postoperati ve high-dose RT and mPCV chemotherapy for patients with anaplastic oligoden droglioma was effective with acceptable toxicity. Further studies are neede d with more patients and longer follow-up to verify these results in this r are disease.