Fifty-three patients with primary or metastatic brain tumors were treated with 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) and 5-fluorouracil (5-FU) and their response was analyzed.
Histological classification of these tumors were as follows: 31 glioblastomas, 4 astrocytomas, 2 ependymomas, 1 oligodendroglioma, 1 meningioma, 2 malignant lymphomas, 3 metastatic tumors, and 9 unverified tumors. Most patients received conventional surgery before chemotherapy and concomitant radiotherapy. ACNU was administered intravenously at a dose of 2 mg/kg once a week for two consecutive weeks. 5-FU was administered at a dose of 10 mg/kg on five consecutive days. If no considerable side effect was observed, ACNU administration was repeated every eight weeks. The effectiveness of the chemotherapeutic regimen was evaluated by CT findings.
The results of the present study can be summarized as follows. The overall response rate of the combined treatment was 24%. There was no statistically significant difference in the responsiveness according to tumor type and dose of ACNU. Survival rates of the patients with glioblastoma (31 cases) were 90% for six months, 67% for 1 year, 27% for 2 years, 8% for 3 years, and 0% for 5 years. As for side effects, 58% of the patients showed delayed bone marrow depression in the form of leukocytopenia, thrombocytopenia, or both between the fourth and fifth week after treatment. This was the major toxic manifestation and was usually transient.
The results were sufficiently encouraging to support further study of these chemotherapeutic agents.