Low-grade gliomas: when to treat?
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Brain Neoplasms↗
Biomedical subjects
W R Shapiro
Publications and source records attributed to W R Shapiro.
Vasogenic brain edema induced by arachidonic acid: role of extracellular arachidonic acid in blood-brain barrier dysfunction.
The effects of free arachidonic acid on the capillary permeability of normal rat brains were studied by measuring the regional uptake of [14C]aminoisobutyric acid by a quantitative autoradiographic technique. Intracerebral infusion of sodium arachidonate increased capillary permeability in a dose-dependent manner up to a concentration of 2 mmol/L. A high dose of arachidonic acid (more than 5 mmol/L) produced marked tissue destruction around the injection site (needle track) and increased capillary permeability less than 2 mmol/L arachidonic acid did. A time-course study demonstrated that about 80% of the maximum increase in capillary permeability produced by arachidonic acid was observed within 2 hours after the infusion was initiated. In addition, capillary permeability gradually increased with time up to 24 hours, after which it declined to about half of the maximum increase 48 hours after infusion. These effects of arachidonic acid on capillary permeability were localized within about 1.6 mm around the injection site. Pretreatment with dexamethasone did not completely, but did significantly, inhibit the arachidonic acid-induced increase in capillary permeability. The inhibitory effect of dexamethasone was completely suppressed by the administration of actinomycin D, which inhibits de novo protein synthesis, 1 hour before the treatment with dexamethasone. These results suggest that arachidonic acid, which is released and accumulated in the extracellular space, increases the capillary permeability of the brain in at least two different ways. One is the direct action of the arachidonic acid itself, which can stimulate perturbation of the membrane of the capillary endothelial cells, thus promoting an increase in capillary permeability.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
A randomized comparison of intra-arterial versus intravenous BCNU, with or without intravenous 5-fluorouracil, for newly diagnosed patients with malignant glioma.
This Phase III trial tested the efficacy and safety of intra-arterial 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) for the treatment of newly resected malignant glioma, comparing intra-arterial BCNU and intravenous BCNU (200 mg/sq m every 8 weeks), each regimen without or with intravenous 5-fluorouracil (1 gm/sq m three times daily given 2 weeks after BCNU). All patients also received radiation therapy. A total of 505 patients were randomly assigned within the study. Fifty-seven patients were excluded, primarily because of neuropathology error, and the remaining 448 patients constituted the Valid Study Group. Of the total 505 patients, 190 patients could not receive intra-arterial BCNU and 315 patients were randomly assigned to receive intra-arterial (167 patients) and intravenous (148 patients) BCNU. Actuarial analysis (log-rank) demonstrated reduced survival for the intra-arterial group (p = 0.03). Serious toxicity was observed in the intra-arterial group; 16 patients (9.5%) developed irreversible encephalopathy with computerized tomography evidence of cerebral edema, and 26 patients (15.5%) developed visual loss ipsilateral to the infused carotid artery. Administration of 5-fluorouracil did not influence survival. The survival rate between the intravenous and the intra-arterial BCNU patients with glioblastoma multiforme did not differ, but was worse for intra-arterial BCNU patients with anaplastic astrocytoma than for those receiving intravenous BCNU (p = 0.002). Neuropathologically, intra-arterial BCNU produced white matter necrosis. It is concluded that intra-arterial BCNU is neither safe nor effective in prolonging survival when administered by the methods used in this study of newly diagnosed patients with malignant glioma.
Adolescent↗
Brain tumors.
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Antineoplastic Combined Chemotherapy Protocols↗
Chemotherapy of malignant gliomas: studies of the BTCG.
Phase III Trial 8,301 tested the efficacy and safety of intraarterial (IA) BCNU for the treatment of newly resected malignant glioma, comparing IA BCNU vs intravenous (IV) BCNU (200 mg/m2 q 8 wks), each regimen without or with IV 5-FU (1 g/m2/d x 3 two wks after BCNU). All patients also received radiation therapy. 505 patients entered the study; 448 were in the Valid Study Group (VSG). Excluding 190 patients who for medical reasons were not eligible for IA BCNU, 315 patients were randomized between IA (167) and IV (148) BCNU. Actuarial analysis (log-rank) demonstrated worse survival for the IA group (p = 0.002). Serious toxicity was observed in the IA group; 16 patients (9.5%) developed irreversible encephalopathy with CT evidence of cerebral edema, and 26 patients developed visual loss ipsilateral to the infused carotid artery. 5-FU did not influence survival. Survival between the IV and the IA BCNU patients with glioblastoma multiforme did not differ, but was worse for IA BCNU patients with anaplastic astrocytoma than for IV BCNU (p = 0.002). Neuropathologically, IA BCNU produced white matter necrosis. IA BCNU is neither safe nor effective. Phase II Trial 8420, compared IA cisplatin, 60 mg/m2 every 4 wks, vs IV PCNU, 100 mg/m2 q 8 wks; 311 patients were randomized. Preliminary results have been presented. Severe encephalopathy occurred in only 1.5% of patients receiving IA cisplatin. The median survival of the IV PCNU patients was 11.8 months; that of the IA cisplatin patients was 9.4 months, not statistically different.(ABSTRACT TRUNCATED AT 250 WORDS)
Antineoplastic Combined Chemotherapy Protocols↗
Increased capillary permeability in rat brain induced by factors secreted by cultured C6 glioma cells: role in peritumoral brain edema.
To investigate whether brain tumors secrete a factor(s) responsible for peritumoral brain edema, we studied the effect of conditioned medium from cultured C6 glioma cells on rat brain capillary permeability. Three different fractions of conditioned medium were obtained. SUP-N was a culture supernatant incubated 4 hours in serum-free medium. SUP-C was the 60-100 fold concentrated fraction obtained by dialysis-concentration of SUP-N; it contained 950 micrograms/ml of protein greater than 10 k-daltons from 3 x 10(8) cells. SUP-L was a water-dispersible lipid fraction from SUP-N; the major components of SUP-L were neutral lipids and free fatty acids. The supernatant fractions and their corresponding control solutions were infused into normal rat brain, and capillary permeability was determined using quantitative autoradiography by measuring the unidirectional entry constant, K (micrograms l/g.min), of 14C-alpha-aminoisobutyric acid (14C-AIB) into brain tissue. SUP-C and SUP-L significantly increased capillary permeability of normal brain; the effect of SUP-C was more intense and extensive than that of SUP-L. The highest mean K value (Kmax) of SUP-C was 10.83 +/- 0.99 and that of the control was 2.53 +/- 0.22 (p less than 0.001). The Kmax of SUP-L was 5.61 +/- 0.23 and that of the control was 2.67 +/- 0.36 (p less than 0.01). A time-course study after infusion of SUP-C demonstrated that more than 1.5 hours is required for the supernatant fraction to open the barrier and that the effect of SUP-C was reversible. The increase of capillary permeability induced by SUP-C was significantly inhibited by pretreatment of rats with dexamethasone (10 mg/kg, ip) 1 hour before intracerebral infusion of SUP-C (Kmax (untreated): 8.30 +/- 0.82, Kmax (treated): 1.33 +/- 0.64, p less than 0.001). These results indicate that experimental brain tumors secrete at least two different diffusible factors responsible for capillary endothelial leakage in normal brain. One is a protein of molecular weight greater than 10 k-daltons, whose effect is inhibited by glucocorticoids, and the other is a waterdispersible lipid.
Animals↗
Possible mechanism of vasogenic brain oedema induced by arachidonic acid.
Free arachidonic acid was infused into normal rat brains and the effect of arachidonic acid on capillary permeability was investigated by measuring the regional uptake of 14C-aminoisobutyric acid with a quantitative autoradiographic method. Arachidonic acid increased capillary permeability in a dose-dependent manner up to 2 mM. A high dose of arachidonic acid (greater than 5 mM) produced a profound tissue destruction around the needle track and less increased capillary permeability than 2 mM arachidonic acid. Time-course study disclosed that arachidonic acid markedly increased capillary permeability within 2 hours after infusion, and continued to increase with time to 24 hours. The effect of 48 hours infusion was about a half of that at 24 hours, indicating that the effect of arachidonic acid was partially reversible. Pretreatment with dexamethasone significantly inhibited the arachidonic acid-induced increase in capillary permeability and the administration of actinomycin D 1 hour before the pretreatment with dexamethasone suppressed the inhibitory effect of dexamethasone. These results suggest that arachidonic acid, which is deposited in the extracellular space, increases brain capillary permeability by two different ways. One is the direct detergent effect of arachidonic acid, and the other is the effect of arachidonic acid that is released from the membrane by the activation of phospholipase A2.
Animals↗
Human malignant gliomas secrete a factor that increases brain capillary permeability: role in peritumoural brain oedema.
The effect of conditioned media obtained from two human malignant gliomas and normal human glia on rat brain capillary permeability was investigated by measuring the entry of 14C-aminoisobutyric acid by a quantitative autoradiographic method. Conditioned media were concentrated 50-fold to create SUP-C. The SUP-C contained proteins with a molecular weight greater than 10 kD. The SUP-C from glioma cells markedly increased brain capillary permeability, whereas that from normal glial cells did not. The activity of capillary permeability factor in the SUP-C was significantly inhibited by pretreatment of animals with dexamethasone or BW755C (lipoxygenase inhibitor), but not with indomethacin. On the other hand, coincubation of glioma cells with dexamethasone produced SUP-C whose capillary permeability activity was about one and a half times greater than that without dexamethasone. These results indicate that human malignant glioma cells secrete a protein factor that increases brain capillary permeability. Glucocorticoids inhibit the effect of the factor by directly acting on capillary endothelial cells, possibly through the inhibition of phospholipase A2 activity, resulting in a decrease of lipoxygenase rather than cyclo-oxygenase products.
Aminoisobutyric Acids↗
Temporal effects of dexamethasone on blood-to-brain and blood-to-tumor transport of 14C-alpha-aminoisobutyric acid in rat C6 glioma.
We used quantitative autoradiography (QAR) to evaluate the effect of systemically administered dexamethasone on capillary permeability in brain tumors and surrounding brain. Rats bearing unilateral right hemispheric C6 gliomas were studied at one and twelve hours after 10 mg/kg of intraperitoneal dexamethasone. Capillary permeability was determined by measuring unidirectional blood-to-brain and blood-to-tumor transport of 14C-alpha aminoisobutyric acid (14C-AIB) over fifteen minutes. 14C-AIB entry into tumor, brain adjacent-to-tumor (BAT), and ipsilateral and contralateral cortices was determined and expressed as a unidirectional transfer constant, K. Nontreated tumor K was more than two-fold greater than K for BAT and ten-fold greater than ipsilateral cortical K, confirming substantial barrier disruption in tumor. In addition, the K for BAT was also significantly greater than K for cortex, indicating that the barrier in the peritumoral region was also disrupted. One hour after dexamethasone treatment, tumor K fell to 63% of its pretreatment value (p less than 0.025). By twelve hours post-treatment, tumor K fell to 25% of the untreated value (p less than 0.001) and to 47% of the one-hour value (p less than 0.005). BAT K fell to 29% of its untreated value (p less than 0.02) and to 46% of its one-hour value (p less than 0.02). By 12 hours, ipsilateral cortical K fell to 67% of the untreated cortical value (p less than 0.05). Compared to untreated values, there was no significant difference between contralateral cortical K at either one or twelve hours.(ABSTRACT TRUNCATED AT 250 WORDS)
Aminoisobutyric Acids↗
Capillary permeability factor secreted by malignant brain tumor. Role in peritumoral brain edema and possible mechanism for anti-edema effect of glucocorticoids.
Conditioned media from two human malignant gliomas, C6 rat glioma, Walker 256 carcinosarcoma, and normal human glia were concentrated 50-fold to create a culture supernatant (SUP-C). The effect of SUP-C on rat brain capillary permeability was investigated by measuring the entry of 14C-aminoisobutyric acid (14C-AIB) by means of quantitative autoradiography. The SUP-C contained proteins with a molecular weight of 10 kD or greater. The SUP-C from all tumor cells markedly increased brain capillary permeability, indicating the presence of a permeability factor, whereas that from normal glial cells did not. Glioma cells produced more factor after incubation for 20 hours than 4 hours. The activity of capillary permeability factor in the SUP-C was inhibited by pretreatment of animals with BW755C (lipoxygenase inhibitor), but not with indomethacin (cyclo-oxygenase inhibitor). Pretreatment of animals with dexamethasone prior to intracerebral infusion of tumor SUP-C significantly reduced the factor-induced increase in capillary permeability. On the other hand, coincubating glioma cells with dexamethasone produced SUP-C with a permeability activity that was about one and a half times greater than that without dexamethasone. These results indicate that glucocorticoids produce their anti-edema effects by directly acting on capillary endothelial cells, possibly through the inhibition of phospholipase A2 activity, resulting in a decrease of lipoxygenase rather than cyclo-oxygenase products. The production of capillary permeability factor by tumor cells was not inhibited, but rather enhanced, by administration of glucocorticoids.
4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyraz↗
Fatal necrotizing encephalopathy complicating treatment of malignant gliomas with intra-arterial BCNU and irradiation: a pathological study.
We describe the neuropathologic findings at autopsy in six patients who developed a progressive encephalopathy complicating the treatment of malignant gliomas with combined intra-arterial 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and cerebral irradiation. Four brains were free of tumor and one contained a microscopic focus of residual glioma. In only one case was there evidence of tumor progression. A disseminated process characterized by miliary foci of necrosis with mineralizing axonopathy was present in all cases, restricted to the internal carotid distribution of the perfused hemisphere and involving primarily though not exclusively the white matter, which was diffusely and severely edematous. This was combined in 3 cases with a histologically dissimilar, massive necrotizing leukoencephalopathy indistinguishable from pure radionecrosis. Much of the toxicity of this therapy is mediated by vascular injury, but the disseminated necrotizing lesion probably reflects, at least in part, direct neural damage.
Brain Diseases↗
Acute effects of low-dose cranial irradiation on regional capillary permeability in experimental brain tumors.
To determine the acute effects of low-dose cranial irradiation (CRT) on regional capillary permeability (RCP) of normal brain, brain tumor and damaged brain surrounding the tumor, we used quantitative autoradiography (QAR) to measure regional blood-to-tissue transport (K) of [14C]aminoisobutyric acid (AIB) in experimental C6 brain tumors 3-4 h after a single dose of 3 Gy CRT. K increased 63% in cortex, 30% in basal ganglia and 31% in brain surrounding the tumor (BST) vs. controls (P less than 0.005). K did not change in the tumor or in the brain adjacent to the tumor (BAT), suggesting that capillaries of normal parenchyma are more sensitive to the acute effects of CRT than capillaries of damaged parenchyma or tumor.
Aminoisobutyric Acids↗
Results of a randomized trial comparing BCNU plus radiotherapy, streptozotocin plus radiotherapy, BCNU plus hyperfractionated radiotherapy, and BCNU following misonidazole plus radiotherapy in the postoperative treatment of malignant glioma.
In Brain Tumor Cooperative Group Study 77-02, eleven institutions randomized 603 adult patients with supratentorial malignant glioma to one of four treatment groups following surgery: conventional radiotherapy (6000 cGy in 30-35 fractions) + BCNU, conventional radiotherapy + streptozotocin, hyperfractionated (twice daily) radiotherapy (6600 cGy in 60 fractions) + BCNU, and conventional radiotherapy with misonidazole followed by BCNU. Data were analyzed for the total randomized population and for the 557 patients (86% with glioblastoma multiforme) who met protocol eligibility specifications (including confirmed histopathology on central review). Median survival was approximately 10 months following randomization. Overall there was no statistically significant difference in survival among the four groups. Among non-glioblastoma patients, the misonidazole group appeared to have poor survival. Peripheral neuropathy was a dose-limiting toxicity with misonidazole. It is concluded that neither the addition of misonidazole nor hyperfractionated radiotherapy as given in this protocol offered any advantage over conventional radiotherapy plus either BCNU or streptozotocin for treatment of malignant glioma.
Adolescent↗
Experimental meningeal carcinomatosis selectively depresses local cerebral glucose utilization in rat brain.
Using quantitative autoradiography, we investigated the effect of meningeal carcinomatosis on local cerebral glucose utilization (LCGU). A rat model of meningeal carcinomatosis using Walker 256 tumor was used. LCGU was evaluated using 14C-2-deoxy-D-glucose according to the Sokoloff method. Thirty-one neuroanatomic structures were evaluated, both separately and as part of five functional or neuroanatomic groups: olfactory, auditory, visual, limbic, and white matter. The relationship between tumor and LCGU of underlying brain was examined. Compared with controls, there was no global change of LCGU in the experimental group that applied to all structures. However, mean LCGU was significantly depressed in olfactory cortex, temporal cortex, olfactory tubercle, amygdala, caudate/putaman, inferior colliculus, medial geniculate, anterior commissure, and corpus callosum, and the functional groups that make up the olfactory and auditory systems. There was no correlation between extent of regional tumor burden and degree of depression of LCGU in underlying structures. In meningeal carcinomatosis, tumor results in selective regional depression of LCGU. This occurs both in structures underlying tumor and those anatomically remote, but in certain cases, functionally related to structures subadjacent to tumor. These data may help to explain the diversity of neurologic dysfunction seen in patients with meningeal cancer.
Analysis of Variance↗
Randomized trial of three chemotherapy regimens and two radiotherapy regimens and two radiotherapy regimens in postoperative treatment of malignant glioma. Brain Tumor Cooperative Group Trial 8001.
Within 3 weeks of definitive surgery, 571 adult patients with histologically confirmed, supratentorial malignant gliomas were randomly assigned to receive one of three chemotherapy regimens: BCNU (1,3-bis(2-chloroethyl)-1-nitrosourea) alone, alternating courses (every 8 weeks) of BCNU and procarbazine, or BCNU plus hydroxyurea alternating with procarbazine plus VM-26 (epipodophyllotoxin). Patients accrued in 1980 and 1981 were to receive 6020 rads of whole-brain radiotherapy concurrent with the first course of chemotherapy. Patients accrued in 1982 and 1983 were randomly assigned to receive either whole-brain irradiation as above, or 4300 rads of whole-brain radiotherapy plus 1720 rads coned down to to the tumor volume. The data were analyzed for the total randomized population and separately for the 510 patients, termed the "Valid Study Group (VSG)," who met protocol eligibility specifications (including central pathology review), 80% of whom had glioblastoma multiforme. The median survival times from time of randomization for the three chemotherapy groups of the VSG ranged from 11.3 to 13.8 months, and 29% to 37% of the patients survived for 18 months (life-table estimate); the differences between these groups were not statistically significant. Survival differences between the radiotherapy groups were small and not statistically significant. It is concluded that, for malignant glioma, giving part of the radiotherapy by coned-down boost is as effective as full whole-brain irradiation, and that multiple-drug chemotherapy as outlined in this protocol conferred no significant survival advantage over BCNU alone.
Antineoplastic Combined Chemotherapy Protocols↗