Intracarotid VP-16 in malignant brain tumors

Twenty-eight patients with malignant brain tumors (16 with primary brain tumors and 12 with brain metastases) progressing after cranial irradiation with or without chemotherapy received varying doses of intracarotid VP-16. Courses of therapy were repeated every 4 weeks along with computerized axial tomography scan and neurologic examination. Of 15 evaluable patients with primary malignant brain tumors, 1 responded to therapy and 5 had no immediate tumor progression for 2–10 months. None of 12 evaluable patients with brain metastases responded to intracarotid VP-16 although 5 had no immediate tumor progression from 1–4 months. Side effects of treatment were uncommon. Using this route of administration, intracarotid VP-16 does not appear to increase response rates in patients with primary malignant brain tumors, compared with results reported for intravenous VP-16.     

A correlative study ofin vivo andin vitro labeling index using bromodeoxyuridine in human brain tumors

The labeling index (LI) of 216 cases of human brain tumors was determined by the immunohistochemical technique with monoclonal antibody to bromodeoxyuridine (BrdU). The proliferative potential of 110 cases was estimated using the intra-operative intravenous infusion of BrdU at a dose of 200 mg/sq m. In another 106 cases, thein vitro technique of incubating freshly resected tumor tissue fragments with 100 M bromodeoxyuridine was used. The BrdU LI in these tumors was then correlated with the histological types and the data as determined by both thein vivo andin vitro BrdU incorporation were compared. The results indicate that althoughin vivo andin vitro techniques could possibly provide equivalent data in some histologic types, a clear statistically valid proof however is not apparent from this study.     

Enhancement of ACNU cytotoxicity by pretreatment withO 6-methylguanine in ACNU-resistant brain tumors

Summary O ⁶-Methylguanine is a substrate of the DNA repair enzymeO ⁶-methylguanine-DNA methyltransferase, which is involved in the repair mechanism of DNA damage induced by chloroethylnitrosoureas such as 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU). We tested the enhancement effect ofO ⁶-methylguanine pretreatment on ACNU cytotoxicity in ACNU-resistant brain tumors. Exposure toO ⁶-methylguanine at various times ranging from 2 to 48 hours increased the cytotoxic effects of ACNU on C6-1 cells, and this effect was highest at higher concentrations 500 and 1,000 M. Colorimetric cytotoxicity assay revealed at least a two-fold increase in ACNU cytotoxicity relative to controls withoutO ⁶-methylguanine. Intraarterial ACNU after treatment withO ⁶-methylguanine (two intravenous bolus injections of 80 and 40 mg/kg) significantly (P < 0.05 or P < 0.01) reduced the proliferation activity of transplanted C6-1 tumors for 96 hours after injection, whereas intravenous ACNU together withO ⁶-methylguanine significantly (P < 0.05) reduced C6-1 activity for only 48 hours. Thus, pretreatment withO ⁶-methylguanine prolonged the suppression effect of ACNU. The C6-1 tumors treated only with intravenous or intraarterial ACNU showed transient inhibition and rapid regrowth for 24 hours after treatment. These results indicate thatO ⁶-methylguanine increases ACNU cytotoxicity in anin vitro andin vivo brain tumor model.     

Sensitivity of human malignant intracranial tumors against MCNU in vitro in comparison to ACNU and BCNU

Summary An in vitro chemosensitivity test was carried out in 50 specimen of human malignant intracranial tumors. Aim of the study was to evaluate the proportion of sensitivity against MCNU (Ranomustine) in comparison to ACNU and BCNU. 47 tests were evaluable. Mean viability of the specimen was 83.3 ± 18.7%, mean plating efficiency was 0.068 ± 0.051%. 9/47 settings revealed sensitivity against MCNU in vitro (ACNU: 10/47; BCNU: 16/46). There was no advantage of MCNU concerning age or sex of the patients. Brain metastases seemed to be slightly more frequent sensitive against MCNU than primary brain tumors. Cross resistance between ACNU, BCNU and MCNU was rather high. The results of this in vitro series do not encourage a clinical trial of MCNU as an alternative to the commonly used nitrosoureas.Behring Werke, D-3550 Marburg/Lahn, FRG     

Clinicopathological features, MIB-1 labeling index and apoptotic index in recurrent astrocytic tumors

This is a study of 64 cases of recurrent astrocytic tumors of all four WHO grades wherein a comparative evaluation of initial vs. recurrent tumor was done with respect to histological grading, MIB-1 labeling index (LI) and apoptotic index (AI). The aim was to identify factor/s that could influence interval to recurrence and/or malignant progression. Recurrence was noted in all grades and upon recurrence, 93.3% of grade II (low grade diffuse) astrocytomas and 63.6% of grade III anaplastic astrocytomas underwent malignant progression. However, none of the Grade I tumors showed evidence of malignant progression. Though interval to recurrence varied considerably, there was a correlation with histological grade of the initial tumor in that grade I and II tumors had a significantly longer mean interval to recurrence (43 months and 54.8 months respectively) as compared to grade III and IV (glioblastoma multiforme) tumors (17.6 and 12.8 months respectively). The interval to recurrence was also longer for grade II and III tumors which showed progression on recurrence (55.3 months for Grade II->Grade III; 54 months for Grade II->Grade IV and 20.6 months for Grade III->IV) as compared to tumors which recurred to the same grade (12.5 months for Grade III->Grade III and 12.8 months for Grade IV->Grade IV). A statistically significant inverse correlation of MIB-1 LI with interval to recurrence was noted. Higher the MIB-1 LI, shorter was the interval to recurrence. Further a cut off MIB-1 LI value of 2.8% could be proposed in predicting recurrence free survival. Interestingly, MIB-1 LI of grade II tumors, which had progressed to grade IV was significantly higher than MIB-1 LI of grade II tumors which had progressed to grade III. Thus, this study establishes the potential role of MIB-1 LI of the initial tumor in determining interval to recurrence. However, apoptotic index has no role in predicting either interval to recurrence or malignant progression.     

Characterization of brain tumors by MRS,DWI and Ki-67 labeling index

Summary With the advent of fast imaging hardware and specialized software, additional non-invasive magnetic resonance characterization of tumors has become available through proton magnetic resonance spectroscopy (MRS), hemodynamic imaging and diffusion-weighted imaging (DWI). Thus, patterns could be discerned to discriminate different types of tumors and even to infer their possible evolution in time. The purpose of this study was to investigate the correlation between MRS, DWI, histopathology and Ki-67 labeling index in a large number of brain tumors. Localized proton spectra were obtained in 47 patients with brain tumors who subsequently underwent surgery (biopsy or tumor removal). We performed MRS with short echo-time (30ms) and metabolic values in spectra were measured using an external software with 25 peaks. In all patients who had DWI, we measured apparent diffusion coefficients (ADC) in the same region of interest (ROI) where the voxel in MRS was located. In most tumors the histological diagnosis and Ki-67 labeling index had been determined on our original surgical specimen. Cho/Cr, (Lip+Mm)/Cr, NAA/(Cho+Cr) and Glx/Cr indexes in MRS allowed discriminating between low- and high-grade gliomas and metastases (MTs). Likewise, absolute ADC values differentiated low- from high-grade gliomas expressed by Ki-67 labeling index. A novel finding was that high Glx/Cr in vivo MRS index (similar to other known indexes) was a good predictor of tumor grading.     

Permeability change and brain tissue damage after intracarotid administration of cisplatin studied by double-tracer autoradiography in rats

Summary The present study was designed to find the reliable parameter(s) for the detection of early neurotoxicity following intracarotid (IC) administration of cisplatin. IC administration was performed for 60 minutes in female Wistar rats derived into four groups according to the dose given (1 mg, 1.2 mg, and 1.5 mg of cisplatin, and normal saline in control rats). Blood-brain barrier (BBB) permeability and local cerebral blood flow (LCBF) were measured by a double-tracer autoradiography technique using 1-[¹⁴ C]--aminoisobutyric acid (¹⁴ C-AIB) and 4-[¹⁸ F] fluoroantipyrine (¹⁸ F-FAP), respectively. Blood chemistry and neuropathology were also examined. BBB permeability was incereased only on the ipsilateral side. This increase was dose-dependent, preceded the brain necrosis, and was statistically significant in the hypothalamus [1.2 mg group), auditory cortex and caudoputamen (1.5 mg group). Renal dysfunction was often observed. The changes in the LCBF did not occur until brain necrosis was noticeable. These findings demonstrate that the increase in the BBB permeability provides a sensitive and reliable indication of an early toxicity to brain tissue following IC administration of cisplatin.Dr. S. Sugimoto was on leave of absence from the Department of Neurosurgery, School of Medicine, Hokkaido University N15W7, Kita-Ku, Sapporo, JapanDr. S. Nagahiro was on leave of absence from the Department of Neurosurgery, Kumamoto University, Medical School, 1-1-1 Honjyo, Kumamoto, 860 Japan     

人实体瘤BUdR离体标记BUdR／DNA双参数FMC测定Tpot的初步研究

探索人实体瘤标本ＢＵｄＲ离体标记ＢＵｄＲ／ＤＮＡ双参数ＦＭＣ测定Ｔｐｏｔ的方法。方法选用头颈肿瘤活检标本及直肠癌手术标本行离体溴脱氧尿嘧啶核苷标记双参数流式细胞术,测定肿瘤潜在培养增时间。结论Ｔｏｐｔ测定应尽可能采用在体ＢＵｄＲ标记,人实体瘤合适的离体标记方法需进一步摸索。     

Thermal enhancement of ACNU and potentiation of thermochemotherapy with ACNU by hypertonic glucose in the BT4An rat glioma

Hyperthermia increases the cytotoxicity of the nitrosourea BCNU (carmustine). Glucose given before treatment may further increase the value of thermochemotherapy, presumably by lowering tumour pH through blood flow reduction. The water-soluble ACNU (nimustine) is an alternative to other nitrosoureas in the treatment of gliomas. The drug is soluble without use of ethanol, and the eye complications when given intra-arterially are reduced compared with similar use of BCNU. The influence of simultaneous hyperthermia on treatment with ACNU, and the value of glucose administered before thermochemotherapy therefore were investigated in the malignant rat glioma BT4An.BD IX rats with subcutaneous BT4An tumours on the hind leg were treated with ACNU (i.p.), or ACNU and locally applied waterbath hyperthermia (44° C for 45 min), with or without previous glucose (6 g/kg i.p. 2 hours before treatment).ACNU (10 or 20 mg/kg) alone and ACNU (20 mg/kg) after previous glucose did not influence tumour growth, compared to the controls.Simultaneous ACNU (10 mg/kg) and hyperthermia clearly was more effective than treatment with hyperthermia alone. Glucose load before treatment further enhanced the effect of combined ACNU and hyperthermia.Glucose before treatment did not change local toxicity or weight profiles of treatment with ACNU alone, or simultaneous ACNU and hyperthermia. Glucose load therefore represented a therapeutic gain when administered before thermochemotherapy with ACNU.     

Capillary permeability in experimental rat glioma and effects of intracarotid CDDP administration on tumor drug delivery

We have examined the capillary permeability within and adjacent to experimental rat gliomas, and the effect of intracarotid administration of cisplatin in this model. Permeability to¹⁴C-sucrose was 25-fold and six-fold higher within the brain tumor and in the tumor periphery and adjacent tissue respectively than in the normal cortex. Intracarotid administration of cisplatin resulted in ten-fold increase in experimental gliomas and also a significant increase in the tumor periphery and adjacent tissue, when compared to the intravenous route. Intracarotid administration of cisplatin to rat did not cause acute vascular damage in either the brain or brain tumor at the dosage used.     

Parenchymal damage in the territory of the anterior choroidal artery following supraophthalmic intracarotid administration of CDDP for treatment of malignant gliomas

We treated ten patients with malignant glioma by intracarotidchemotherapy with cis-diamminedichloroplatinum (CDDP) and/or3-(4-amino-2-methyl-5-pyrimidinyl)methyl-1-(2-chloroethyl)-3-nitrosourea(ACNU). Three of the patients who underwent supraophthalmic intracarotidinfusion of CDDP developed a low-density area in the basal ganglia on CTscan or an enhancing lesion in the hypothalamic region on MRI, with orwithout neurologic symptoms. No patient had such complications withsupraophthalmic infusions of ACNU, or with cervical intracarotid infusion ofCDDP or selective infusion of CDDP via the anterior or middle cerebralarteries. Supraophthalmic intracarotid administration of CDDP may augmentdrug delivery to tumors and prevent visual complications, but is accompaniedby considerable risk of parenchymal damage in the territory of the anteriorchoroidal artery. Possible mechanisms for such complications are discussed.     

Proliferative activity of central neurocytoma: Measurement of tumor volume doubling time,MIB-1 staining index and bromodeoxyuridine labeling index

Central neurocytoma is considered to be a benign intracranial neoplasm, but little is known about the biological behavior of this type of tumor.Proliferative activity of central neurocytoma was measured in 10 cases using MIB-1 staining for Ki-67 antigen.The MIB-1 staining value varied from < 0.1% to 5.6%, to indicating that some of these tumors have proliferative potential similar to that of anaplastic astrocytoma or malignant meningioma. Thebromodeoxyuridine labeling index (BUdR LI, BrdU LI) was measured in 2 cases and the results correlated well with those of the MIB-1 analysis. Tumor volume doubling time (Td) measured in one case was 358 days which is similar to that of malignant meningioma.In one case, the MIB-1 value taken beforeand after 58 Gy of radiation treatment decreased markedly from 5.6%to 0.2%. The other 9 cases were also treated by radiation therapy (50—60 Gy) and no tumor recurrence was observed during follow-up periods ranging from 23 to 160 months. Another two patients with partially removed and 3 with subtotallyremoved tumors showing relatively high MIB-1 values might also have benefited from radiation therapy.     

Isolation and characterization of microvessels from normal brain and brain tumors

We describe a new technique for isolating microvessels from both brain and brain tumors. This method is relatively quick and provides a microvessel preparation free of contamination by other brain tissue. Using this method, structurally intact microvessels from normal rat brain and from a malignant rat astrocytoma were isolated and characterized with light microscopy, scanning electron microrscopy and transmission electron microscopy. In contrast to microvessels derived from normal rat brain, rat astrocytoma microvessels had endothelial cells with multilayered basement membranes, extensive microvilli on the cell surfaces, and a significant increase in the number of pinocytes in the cytoplasm. Furthermore, astrocytoma microvessel endothelial cells had pleomorphic electron dense nuclei with pale perichromatin, whereas the nuclei of endothelial cells of microvessels derived from normal brain tissue were finely granular and homogeneous with characteristically electron dense perichromatin. The morphologic characteristics of the astrocytoma microvessels are similar to the histologic changes seen in astrocytoma tissue in situ, and correlate well with the known altered functions of brain tumor neovasculature.     

Study on brain targeting of raltitrexed following intranasal administration in rats

Purpose: To investigate the levels of raltitrexed (RTX) in blood and different brain tissues in rats and to find out whether there is any direct drug transport from nasal cavity to brain tissues following intranasal (i.n.) administration. Methods: Raltitrexed was administered to male Sprague-Dawley rats either intranasally or intravenously. Drug concentrations in blood and brain tissues were determined at different times post dosing. Results: The plasma levels achieved after i.n. administration were significantly lower than those following intravenous (i.v.) administration (P<0.05) before 120 min; but were significantly higher (P<0.05) after 120 min. Following i.n. administration, RTX concentrations in different brain tissues were constantly detected for quite a long time and differed significantly from each other, the rank order being C _OB>C _OT>C _CR>C _CL. On the contrary, RTX appeared only at the initial two or three time points in different brain regions after i.v. injection, and the concentrations were similar. AUC values in four brain regions by the nasal route were 54- to 121-fold compared with the i.v. route, the drug targeting index (DTI) values of nasal route were 71–158 for different brain regions, and about 99% of RTX content within 360 min in the brain were transported via the olfactory pathway. Conclusions: These results showed that antineoplastic RTX could be directly transported into the brain via the olfactory pathway in rats.     

Prognostic and therapeutic implications of the MIB-1 labeling index in breast cancer

Background  Assessment of tumor proliferative activity is considered to be the most powerful prognostic factor aside from axillary lymph node status. The purpose of this study is to assess the clinical value of measurement of proliferative activity using the MIB-1 labeling index in patients with breast cancer. Methods  Surgical specimens from 36 patients with benign breast disorders and 146 patients with breast cancer were investigated. The MIB-1 labeling index was determined on the specimens stained by immunohistochemical methods as much as possible. Clinical factors associated with the MIB-1 labeling index were reviewed. Results  The MIB-1 labeling index for non-proliferative disorders, proliferative disorders, and breast cancer was 3.4±1.9%, 8.9±6.2% and 20±12%, respectively. The MIB-1 labeling index and tumor size, lymph node metastasis status, and clinical stage according to the TNM classification correlated significantly. Survival rate was inversely correlated with the MIB-1 labeling index. No patient with an MIB-1 labeling index of less than 10% had lymph node metastases, and all are alive without recurrence. Patients with an MIB-1 labeling index of over 30% had an extremely poor prognosis. Conclusions  The MIB-1 labeling index is very useful for predicting both either extremely good or extremely poor prognosis, and axillary lymph node metastasis.     

Current epidemiological trends and surveillance issues in brain tumors

The absence of an overall increase in incidence rates for all primary brain tumors since the 1950s argues against a recently introduced environmental tumorigen impacting these tumors. Historical increases in brain cancer mortality and incidence rates appear to be leveling off following the widespread introduction of CT and MRI scans, indicating that increases in overall rates of malignant tumors are likely to be an artifact of diagnosis and reporting issues. Further studies are needed to understand those tumor types with rates that do appear to be increasing among adults; specifically lymphomas, nerve sheath tumors, pituitary tumors and ependymomas. Patterns of incidence by race, ethnicity, socioeconomic status, and seasonal and regional variation would assist in directing relevant new research questions. Filling in the gap of information on patterns for prevalent, second primaries and metastatic tumors may be useful in understanding the public perception regarding brain tumor rates and would be a valuable addition to healthcare planning tools.     

Putrescine metabolism in human brain tumors

Summary The metabolism of the polyamines, putrescine, spermidine and spermine, was studied in human brain and brain tumors. Samples of brain and tumors were incubated with³H-putrescine and the amounts of labeled polyamines were measured. The amount of putrescine conversion was found to be greater in tumors that in normal brain samples. Furthermore, the metabolism of putrescine in brain tumors was related to tumor type and appeared to correlate with the degree of malignancy. The significance of these findings with regard to positron emission tomographic scanning and therapy of patients with malignant gliomas is discussed.     

MOPP regimen as primary chemotherapy for brain tumors in infants

Summary Seventeen infants with central nervous system malignancies, all with tissue diagnosis, were treated with the combination chemotherapy nitrogen mustard, vincristine, procarbazine and a steroid (MOPP) as primary therapy following surgery. Diagnoses include: 7 astrocytomas (grade: 3-I, 3-II, 1-III), 6 medulloblastomas, 2 ependymoma/astrocytoma mixed, 1 ependymoma and 1 primitive neuroectodermal tumor. Fourteen were under 2 years of age, 2 between 2 and 3 years of age, and 1 between 3 and 4 years of age. Fifteen responded and 2 failed. Of the responders, 6 are in continuous complete remission (median duration 28.9+ months) and 9 are in relapse (median duration of remission 10.3 months). Of the 2 patients who failed and 9 who relapsed, 4 expired and 6 are living in partial or complete remission. We conclude that MOPP therapy is well tolerated, has effectiveness, and allows postponement of potentially debilitating radiotherapy in infants with brain tumors. Address for offprints: Jan van Eys, PhD MD, Department of Pediatrics, Box 87, UT MD Anderson Hospital, 6723 Bertner Avenue, Houston, Texas 77030.     

Intra-arterial administration of carboplatin and the blood brain barrier permeabilizing agent,RMP-7: A toxicologic evaluation in swine

RMP-7 is a bradykinin B2 receptor agonist shown to permeabilize the blood-brain barrier, especially that associated with brain tumors, when administered via both intracarotid and intravenous routes. Both routes of administration are currently being tested in human trials in combination with the chemotherapeutic agent carboplatin as therapy for gliomas. As an essential prerequisite to the initial intracarotid clinical trials, the potential neurotoxicity of intra-arterial administration of RMP-7 (at a high or low dose), alone and in combination with carboplatin, was assessed in anesthetized Red Duroc swine. Five treatment groups were evaluated with each pig receiving a series of alternating, intra-arterial infusions of RMP-7 (or saline) followed by carboplatin (or saline), as follows: (1) vehicle control: saline/saline; (2) carboplatin only control: saline/carboplatin (50 mg total); (3) RMP-7 only control: RMP-7 (750 ng/kg)/saline; (4) low dose combination: RMP-7 (75 ng/kg)/carboplatin (50 mg total); and (5) high dose combination: RMP-7 (750 ng/kg)/carboplatin (50 mg total). For each subject, one of the alternating dosing sequences (above) was repeated four times during a single dosing session which lasted approximately 40 minutes. Assessments during the in-life phase of the study in the pre- and post-treatment periods consisted of heart rate, arterial blood pressure (systolic, diastolic, and mean), blood gases, body weight, general clinical observations (including evaluation for neurological deficit) and clinical pathology (including a comprehensive battery of standard blood coagulation, hematological and serum chemistry tests). In addition, during the time of treatment, heart rate and arterial blood pressure were monitored. The animals were terminated two weeks after dosing and the brain and rete mirabile (distal to site of infusion) were evaluated for gross and histopathological abnormalities. The histopathology analysis included a reader-blinded analysis using low and high power light microscopic examination of both H&E and Kluver-Berrera stained sections through several key cortical and subcortical brain regions. Transient decreases in arterial blood pressure (mean of 10–25 mmHg) were observed in both groups receiving the high dose of RMP-7 (i.e., 750 ng/kg). No other side effects attributable to RMP-7 and/or carboplatin were observed, and clinical observations revealed no evidence of neurologic deficits. Post-mortem examination revealed no evidence of CNS or cerebral vascular pathology attributable to carboplatin and RMP-7. This study demonstrates that intracarotid administration of the maximum tolerated dose of RMP-7 (750 ng/kg) alone, or in combination with carboplatin (50 mg) is not accompanied by any serious adverse effect, apparent cerebrovascular abnormality or neuropathologic consequence and offers further evidence for the safety of this novel therapeutic approach for enhancing delivery of chemotherapeutics to brain tumors.