Misonidazole and CCNU chemotherapy for recurrent primary brain tumor

Combined intra-arterial and systemic chemotherapy for recurrent malignant brain tumors

Seventy-nine patients harboring recurrent brain tumors received four cycles of infraophthalmic carotid injections of 160 mg of carmustine. Two milligrams of intravenous vincristine and 50 mg of oral procarbazine was also administered three times daily for 1 week in conjunction with each BCNU treatment. The response rate was 60% with a median survival for patients with astrocytomas, anaplastic astrocytomas, and glioblastomas of 32, 20, and 6.5 months, respectively. The median survival of the responding patients was 20 months, and the survival at 30 months was 45%. The survival in patients not responding to treatment was 5 months, reflecting the natural history of the tumor. There have been no deaths related to the treatment procedure. No incidents of severe or permanent eye complications or leukoencephalopathy were observed. Based on multivariate survival analysis, only patients with a good performance status who are not steroid dependent are candidates for this treatment.

2-Nitroimidazole potentiation of nitrosourea induced cytotoxicity in subcutaneous implants of rat 9L brain tumor cells

To determine if the 2-nitroimidazole (2-NI) and the nitrosourea (NU) in a brain tumor chemopotentiation trial should be selected on the basis of known structure-activity relationships (electron affinity, lipophilicity, alkylating activity, carbamoylating activity), s.c. implants of rat 9L brain tumor cells were treated with combinations of misonidazole (MISO) or etanidazole (SR-2508) administered under oxic and hypoxic conditions, and BCNU, CCNU or chlorozotocin (CLZ) administered under oxic conditions. Cell kill was assessed by an in vivo to in vitro colony formation assay. To mimic the 'preincubation effect', the 2-NI was injected i.p., and 30 min later the tumor was clamped. After 2 hr, the clamp was released, and the NU administered immediately. MISO (2.5 mmole/kg) and SR-2508 (3.75 mmole/kg) reached the same peak tumor concentration in 30 min. Both 2-NIs were metabolized at the same rate in the clamped tumors; however, metabolism of the 2-NIs by hypoxic cells over the 2 hr clamping period did not produce any measurable s.c. 9L cell kill. The relative effectiveness of the NUs for killing oxic s.c. 9L tumor cells was: BCNU greater than CCNU greater than CLZ. Clamping the tumor prior to NU administration did not change the NU cytotoxicity. No potentiation of the NU cytotoxicity by the 2-NIs was observed in oxic tumors. Although metabolism of MISO by hypoxic cells did not result in potentiation of CLZ cytotoxicity at any dose, it resulted in potentiation of BCNU cytotoxicity at all doses and CCNU cytotoxicity at high doses.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of chemotherapy in the treatment of gliomas in adults

Glioblastomas and previously irradiated recurrent gliomas remain incurable. Chemotherapy is able to palliate patients by shrinking tumors, thereby improving neurological status and quality of life. Chemotherapy may also be capable of prolonging survival in some instances. The effectiveness of chemotherapy against gliomas is comparable to the efficacy of chemotherapy against many other solid tumors. When given in an adjuvant setting along with radiation postoperatively, studies suggest that the nitrosoureas, dibromodulcitol, dianhydrogalactitol, procarbazine, teniposide, dacarbazine, and cisplatin may possibly be useful, although results for many of these drugs are inconclusive. Some chemotherapy combinations also appear to be useful in an adjuvant setting, particularly BCNU plus ifosfamide, BCNU plus cisplatin, CCNU plus dibromodulcitol, and CCNU plus lonidamine. However, there is not yet conclusive evidence that combination chemotherapy is superior to single agent adjuvant chemotherapy in the treatment of gliomas. While the use of chemotherapy prior to postoperative cranial radiation is worthy of further study, it has not to date proven to be more effective than chemotherapy combined with radiation. In patients whose tumors have recurred following radiation, palliation may be achieved with the nitrosoureas, procarbazine, teniposide, and diaziquone. Cisplatin, high dose methotrexate, the interferons, and a variety of other medications also may be of use. As in the case of adjuvant chemotherapy, chemotherapy combinations for recurrent tumor have not been conclusively demonstrated to be superior to single agent treatment, although some CCNU-based combinations are of interest. Many different chemotherapy drugs have been administered by intracarotid infusion. There is a moderately high risk of serious local retinal and neurological toxicity using this approach, and efficacy has not been proven to be improved by this approach. However, further studies of intraarterial administration of chemotherapy are warranted in light of theoretical considerations, pharmacological observations of enhanced local drug concentrations, and the observation that patients who have failed the same drugs intravenously may respond when lower doses of the drug are administered intraarterially. In addition, some patients have had tumor shrinkage in the area infused while tumor has grown in other areas. Thus, while intracarotid chemotherapy must be regarded as still investigational and potentially quite toxic, further studies are indicated. High dose chemotherapy has been administered in combination with autologous bone marrow rescue. High response rates and prolonged survival durations have been reported in some instances, justifying further study despite substantial toxicity.(ABSTRACT TRUNCATED AT 400 WORDS)

A randomized study of CCNU with and without benznidazole in the treatment of recurrent grades 3 and 4 astrocytoma. Report to the Medical Research Council by the Brain Tumor Working Party

In a randomized, double-blind study, 44 patients with recurrent high grade malignant glioma were allocated to chemotherapy of CCNU, with or without benznidazole (BENZO). Of 42 eligible patients, 23 received CCNU alone, and 19 CCNU received BENZO. Only 8 patients received the full 6 courses of treatment. The mean number of courses given was 2.8 for placebo and 3.4 for benznidazole patients. Progressive disease caused termination of treatment early for the majority of patients. There was no evidence of increased toxicity-leucopenia, anemia or thrombocytopenia-in the BENZO group, and only one patient in each treatment group had chemotherapy terminated because of toxicity. The BENZO group did not demonstrate any survival advantage: median survival time was 25 weeks in the BENZO group and 30 weeks in the placebo group. The confidence interval for the treatment difference is wide but excludes a BENZO-related addition of more than 7 months to the median survival time.