Phase II trial of carmustine plus O(6)-benzylguanine for patients with nitrosourea-resistant recurrent or progressive malignant glioma

PURPOSE

We conducted a phase II trial of carmustine (BCNU) plus the O(6)-alkylguanine-DNA alkyltransferase inhibitor O(6)-benzylguanine (O(6)-BG) to define the activity and toxicity of this regimen in the treatment of adults with progressive or recurrent malignant glioma resistant to nitrosoureas.

PATIENTS AND METHODS

Patients were treated with O(6)-BG at an intravenous dose of 120 mg/m(2) followed 1 hour later by 40 mg/m(2) of BCNU, with cycles repeated at 6-week intervals.

RESULTS

Eighteen patients were treated (15 with glioblastoma multiforme, two with anaplastic astrocytoma, and one with malignant glioma). None of the 18 patients demonstrated a partial or complete response. Two patients exhibited stable disease for 12 weeks before their tumors progressed. Three patients demonstrated stable disease for 6, 12, and 18 weeks before discontinuing therapy because of hematopoietic toxicity. Twelve patients experienced reversible > or = grade 3 hematopoietic toxicity. There was no difference in half-lives (0.56 +/- 0.21 hour v 0.54 +/- 0.20 hour) or area under the curve values (4.8 +/- 1.7 microg/mL/h v 5.0 +/- 1.3 microg/mL/h) of O(6)-BG for patients receiving phenytoin and those not treated with this drug.

CONCLUSION

These results indicate that O(6)-BG plus BCNU at the dose schedule used in this trial is unsuccessful in producing tumor regression in patients with nitrosourea-resistant malignant glioma, although stable disease was seen in five patients for 6, 12, 12, 12, and 18 weeks. Future use of this approach will require strategies to minimize dose-limiting toxicity of BCNU such as regional delivery or hematopoietic stem-cell protection.

Phase II study of irinotecan (CPT-11) in children with high-risk malignant brain tumors: the Duke experience

A phase II study of irinotecan (CPT-11) was conducted at Duke University Medical Center, Durham, NC, to evaluate the activity of this agent in children with high-risk malignant brain tumors. A total of 22 children were enrolled in this study, including 13 with histologically verified recurrent malignant brain tumors (glioblastoma multiforme [GBM] 4, anaplastic astrocytoma 1, ependymoma 5, and medulloblastoma/primitive neuroectodermal tumor 3), 5 with recurrent diffuse pontine glioma, and 4 with newly diagnosed GBM. All patients with recurrent tumor had prior chemotherapy and/or irradiation. Each course of CPT-11 consisted of 125 mg/m ( 2 ) per week given i.v. for 4 weeks followed by a 2-week rest period. Patients with recurrent tumors received therapy until disease progression or unacceptable toxicity. Patients with newly diagnosed tumors initially received 3 cycles of treatment to assess tumor response and then were allowed radiotherapy at physician's choice; patients who demonstrated a response to CPT-11 prior to radiotherapy were allowed to continue the drug after radiation until disease progression or unacceptable toxicity. A 25% to 50% dose reduction was made for grade III-IV toxicity. Responses were assessed after every course by gadolinium-enhanced MRI of the brain and spine. Twenty-two patients received a median of 2 courses of CPT-11 (range, 1-16). Responses were seen in 4 of 9 patients with GBM or anaplastic astrocytoma (44%; 95% confidence interval, 11%-82%) (complete response in 2 patients with recurrent GBM lasting 9 months and 48+ months; partial response in one patient with a newly diagnosed midbrain GBM lasting 18 months prior to radiotherapy; and partial response lasting 11 months in 1 patient with recurrent anaplastic astrocytoma), 1 of 5 patients with recurrent ependymoma (partial response initially followed by stable disease lasting 11 months), and none of 5 patients with recurrent diffuse pontine glioma. Two of 3 patients with medulloblastoma/primitive neuroectodermal tumor had stable disease for 9 and 13 months. Toxicity was mainly myelosuppression, with 12 of 22 patients (50%) suffering grade II-IV neutropenia. Seven patients required dose reduction secondary to neutropenia. CPT-11, given in this schedule, appears to be active in children with malignant glioma, medulloblastoma, and ependymoma with acceptable toxicity. Ongoing studies will demonstrate if activity of CPT-11 can be enhanced when combined with alkylating agents, including carmustine and temozolomide.

Comprehensive molecular cytogenetic investigation of chromosomal abnormalities in human medulloblastoma cell lines and xenograft

Cell lines and xenografts derived from medulloblastomas are useful tools to investigate the chromosomal changes in these tumors. Here we used G-banding, fluorescence in situ hybridization (FISH), spectral karyotyping (SKY), and comparative genomic hybridization to study 4 medulloblastoma cell lines and 1 xenograft. Cell line D-425 Med had a relatively simple karyotype, with a terminal deletion of 10q and amplification of MYC in double-minutes (dmins). FISH demonstrated that an apparent isochromosome (17q) by routine karyotyping was actually an unbalanced translocation between 2 copies of chromosome 17. Cell line D-556 Med also had a simple near-diploid stemline with an unbalanced 1;13 translocation resulting in a gain of 1q, an isochromosome (17q), and dmins. These findings were initially described using routine G-banded preparations, and FISH showed that the dmins were an amplification of MYC and the i(17q) was an isodicentric 17q chromosome. The other finding was confirmed by FISH, SKY, and comparative genomic hybridization. Cell lines D-721 Med and D-581 Med had complex karyotypic patterns that could be completely characterized only when FISH and SKY were used. Xenograft D-690 Med also had a complex pattern that FISH and SKY were helpful in completely elucidating. Interestingly, balanced reciprocal translocations were seen as well as complicated unbalanced translocations and marker chromosomes. Comparative genomic hybridization demonstrated only a deletion of 10q22-10q24, supporting the idea that despite the complexity of the chromosomal rearrangements, minimal alterations in the overall chromosomal content had occurred. This study demonstrates that routine cytogenetic preparations are adequate to describe chromosomal abnormalities in occasional medulloblastoma samples, but a broader spectrum of molecular cytogenetic methods is required to completely analyze most of these tumor samples.

Phase II trial of murine (131)I-labeled antitenascin monoclonal antibody 81C6 administered into surgically created resection cavities of patients with newly diagnosed malignant gliomas

PURPOSE

To assess the efficacy and toxicity of intraresection cavity (131)I-labeled murine antitenascin monoclonal antibody 81C6 and determine its true response rate among patients with newly diagnosed malignant glioma.

PATIENTS AND METHODS

In this phase II trial, 120 mCi of (131)I-labeled murine 81C6 was injected directly into the surgically created resection cavity of 33 patients with previously untreated malignant glioma (glioblastoma multiforme [GBM], n = 27; anaplastic astrocytoma, n = 4; anaplastic oligodendroglioma, n = 2). Patients then received conventional external-beam radiotherapy followed by a year of alkylator-based chemotherapy.

RESULTS

Median survival for all patients and those with GBM was 86.7 and 79.4 weeks, respectively. Eleven patients remain alive at a median follow-up of 93 weeks (range, 49 to 220 weeks). Nine patients (27%) developed reversible hematologic toxicity, and histologically confirmed, treatment-related neurologic toxicity occurred in five patients (15%). One patient (3%) required reoperation for radionecrosis.

CONCLUSION

Median survival achieved with (131)I-labeled 81C6 exceeds that of historical controls treated with conventional radiotherapy and chemotherapy, even after accounting for established prognostic factors including age and Karnofsky performance status. The median survival achieved with (131)I-labeled 81C6 compares favorably with either (125)I interstitial brachy-therapy or stereotactic radiosurgery and is associated with a significantly lower rate of reoperation for radionecrosis. Our results confirm the efficacy of (131)I-labeled 81C6 for patients with newly diagnosed malignant glioma and suggest that a randomized phase III study is indicated.

Dendritic cells pulsed with a tumor-specific peptide induce long-lasting immunity and are effective against murine intracerebral melanoma

OBJECTIVE

Dendritic cells (DCs) are specialized cells of the immune system that are capable of generating potent immune responses that are active even within the "immunologically privileged" central nervous system. However, immune responses generated by DCs have also been demonstrated to produce clinically significant autoimmunity. Targeting the epidermal growth factor receptor variant III (EGFRvIII), which is a mutation specific to tumor tissue, could eliminate this risk. The purpose of this study was to demonstrate that DC-based immunizations directed solely against this tumor-specific antigen, which is commonly found on tumors that originate within or metastasize to the brain, could be efficacious.

METHODS

C3H mice were vaccinated with DCs mixed with a keyhole limpet hemocyanin conjugate of the tumor-specific peptide, PEP-3, which spans the EGFRvIII mutation, or the random-sequence peptide, PEP-1, and were intracerebrally challenged with a syngeneic melanoma expressing a murine homologue of EGFRvIII.

RESULTS

Systemic immunization with DCs mixed with PEP-3-keyhole limpet hemocyanin generated antigen-specific immunity. Among mice challenged with intracerebral tumors, this resulted in an approximately 600% increase in the median survival time (>300 d, P < 0.0016), relative to control values. Sixty-three percent of mice treated with DCs mixed with the tumor-specific peptide survived in the long term and 100% survived rechallenge with tumor, indicating that antitumor immunological memory was also induced.

CONCLUSION

In a murine melanoma model, immunization with DCs mixed with tumor-specific peptide results in an antigen-specific immunological response that recognizes the EGFRvIII mutation, has potent antitumor efficacy against intracerebral tumors that express EGFRvIII, and results in long-lasting antitumor immunity.

Endodermal cyst of the oculomotor nerve

Endodermal cysts are rare congenital intracranial lesions. Although histologically benign, they can become symptomatic as a result of mass effect and cause neurological deficits. We report a 30-year-old woman who presented with paresis of her right oculomotor nerve. Magnetic resonance imaging showed a 13 x 8-mm cystic lesion originating from the right oculomotor nerve at its exit from the mesencephalon. She underwent craniotomy, biopsy, slit resection, and drainage of the cyst. To our knowledge, endodermal cysts have not been previously described in relation to the oculomotor nerve.

CD34 and dural fibroblasts: the relationship to solitary fibrous tumor and meningioma

Intracranial solitary fibrous tumors (SFTs) are typically dural-based, CD34-positive neoplasms of uncertain histogenesis. We examined ten cases of meninges obtained at autopsy from patients with no history of neurological illness, head trauma, or neurosurgical intervention, and ten cases of typical meningiomas with attached dural margins not involved by tumor. All cases were immunostained with CD34. CD34 reactivity was noted in the long, thin delicate processes of dural fibroblasts preferentially located in the meningeal portion of the dura rather than the periosteal portion. No CD34 reactivity was identified in the arachnoid or pia mater, except in some endothelial cells. One supratentorial dural-based fibrous nodule and one SFT within the confines of the fourth ventricle showed strong and diffuse reactivity to CD34, bcl-2, and vimentin, and were negative for epithelial membrane antigen (EMA), S-100 protein, glial fibrillary acidic protein, smooth muscle actin, and desmin. We also describe a meningothelial meningioma within which a well circumscribed SFT-like nodule was embedded. The SFT-like nodule was strongly CD34 positive and EMA negative, and the meningioma was strongly EMA positive and CD34 negative. Fibroblasts of the dural border cell layer are attached to the underlying arachnoid, and their inclusion with arachnoidal stromal elements and pial-based tela choroidea during formation of choroid plexus interstitium may account for intraventricular SFTs. Our results suggest that SFTs and dural-based fibrous nodules derive from CD34-positive dural-based fibroblasts, and that CD34 reactivity in meningiomas may result from inclusion of dural fibroblasts within the neoplasm.

Phase I study of Gliadel wafers plus temozolomide in adults with recurrent supratentorial high-grade gliomas

Both Gliadel wafers [1,3-bis(2-chloroethyl)-1-nitrosourea] and temozolomide (TEMO) have been shown in independent studies to prolong survival of patients with recurrent malignant glioma following surgery and radiotherapy. On the basis of preclinical evidence of synergism between Gliadel wafers and TEMO, a phase I study was designed to evaluate the toxicity of combining these 2 agents in the treatment of patients with recurrent supratentorial malignant glioma. All patients had surgical resection of the tumor at relapse, and up to 8 Gliadel (3.85%) wafers were placed in the surgical cavity following resection. Two weeks after surgery, TEMO was given orally daily for 5 days. Cohorts of 3 patients received TEMO at daily doses of 100 mg/m2, 150 mg/m2, and 200 mg/m2, respectively. Patients were assessed for toxicity 4 weeks after start of the first course of TEMO. Contrast-enhanced MRI of the brain was used to assesstumor response after the first cycle of TEMO. Patients with stable disease or response after the first cycle of TEMO were allowed to continue treatment at the same dose every 4 weeks for 12 cycles or until disease progression or unacceptable toxicity. Ten patients with a median age of 47 years (range, 22-66 years) were enrolled in this study. There were 7 patients with glioblastoma multiforme and 3 patients with anaplastic astrocytoma. Three patients were treated with TEMO at the first dose level of 100 mg/m2, 4 at the second dose level of 150 mg/m2, and 3 at the third dose level of 200 mg/m2. The 10 patients received a median of 3 cycles (range, 1-12 cycles) of TEMO following placement of Gliadel wafers. The treatment was well tolerated, with only 1 patient suffering grade III thrombocytopenia at the highest dose level. Two patients at each dose level had no evidence of disease progression after treatment. Four patients suffered progressive disease on therapy. Our study demonstrates that TEMO can be given safely after placement of Gliadel (3.85%) wafers. The recommended dosage for TEMO for a phase II study of this combination is 200 mg/m2 per day for 5 days.

March 2000: A 16 year old female with a cerebellar mass

The March COM: A 16 year old female presented with headaches and cerebellar dysfunction. MR images showed a mass lesion of the right cerebellar hemisphere with mass effect on the medulla. The mass exhibited a striated pattern of alternating isointense and hypointense zones on T1-weighted images that did not contrast enhance. The lesion was hyperintense on T2-weighted images, and also showed a striated appearance. A suboccipital craniotomy and resection of the lesion was performed. Microscopically, the specimen consisted of widened folia and a disorganized cerebellar architectonic pattern in which the internal granular cell layer was occupied by a population of large dysmorphic nerve cell bodies. Patient's diagnosed with Lhermitte-Duclos disease must be adequately evaluated for Cowden's syndrome.

A genetically tractable model of human glioma formation

Gliomas remain one of the deadliest forms of cancer. Improved therapeutics will require a better understanding of the molecular nature of these tumors. We, therefore, mimicked the most common genetic changes found in grade III-IV gliomas, disruption of the p53 and RB pathways and activation of telomere maintenance and independence from growth factors, through the ectopic expression of the SV40 T/t-Ag oncogene, an oncogenic form of H-ras (H-ras(V12G)), and the human telomerase catalytic subunit hTERT in normal human astrocytes. The resulting cells displayed many of the hallmarks of grade III-IV gliomas, including greatly expanded life span and growth in soft agar and, most importantly, were tumorigenic with pathology consistent with grade III-IV neuroectodermal tumors in mice. This model system will, for the first time, allow the biological significance of selected genetic alterations to be studied in human gliomas.

Ham56-immunoreactive macrophages in untreated infiltrating gliomas

CONTEXT

Classic diagnostic neuropathologic teachings have cautioned against making the diagnosis of neoplasia in the presence of a macrophage population. The knowledge of macrophage distribution should prove useful when confronted with an infiltrating glioma containing macrophages.

OBJECTIVE

To identify macrophages in untreated, infiltrating gliomas using the monoclonal antibody HAM56, and to confirm their presence in an untreated glioblastoma multiforme (GBM) with the serial analysis of gene expression (SAGE) method.

METHODS

We evaluated the presence of macrophages in 16 cases of untreated, supratentorial infiltrating gliomas with the macrophage monoclonal antibody HAM56. We performed SAGE for one case of GBM and for normal brain tissue.

RESULTS

In World Health Organization (WHO) grade II well-differentiated astrocytoma and oligodendroglioma, HAM56 reactivity was noted only in endothelial cells, and unequivocal macrophages were not identified. In WHO grade III anaplastic astrocytoma and anaplastic oligodendroglioma, rare HAM56-positive macrophages were noted in solid areas of tumor. In WHO grade IV GBM, HAM56-positive macrophages were identified in areas of solid tumor (mean labeling index, 8.6%). In all cases of GBM, nonquantitated HAM56-positive macrophages were identified in foci of pseudopalisading cells abutting necrosis and in foci of microvascular proliferations. In none of the cases were granulomas or microglial nodules found, and there was no prior history of surgical intervention, radiation therapy, chemotherapy, or head trauma in these cases. By SAGE, the macrophage-related proteins osteopontin and macrophage-capping protein were overexpressed 12-fold and eightfold, respectively, in one untreated GBM compared with normal brain tissue. In this case, numerous HAM56-positive macrophages (labeling index, 24.5%) were present in the solid portion of tumor, and abundant nonquantified macrophages were identified in foci of pseudopalisading cells abutting necrosis and in foci of microvascular proliferations.

CONCLUSIONS

This study confirms the utility of the monoclonal antibody HAM56 in identifying macrophages within untreated infiltrating gliomas. The overexpression of macrophage-related proteins in one case of GBM as detected by SAGE signifies that macrophages may be present in untreated GBMs.

Phase I trial results of iodine-131-labeled antitenascin monoclonal antibody 81C6 treatment of patients with newly diagnosed malignant gliomas

PURPOSE

To determine the maximum-tolerated dose (MTD) of iodine-131 ((131)I)-labeled 81C6 antitenascin monoclonal antibody (mAb) administered clinically into surgically created resection cavities (SCRCs) in malignant glioma patients and to identify any objective responses with this treatment.

PATIENTS AND METHODS

In this phase I trial, newly diagnosed patients with malignant gliomas with no prior external-beam therapy or chemotherapy were treated with a single injection of (131)I-labeled 81C6 through a Rickham reservoir into the resection cavity. The initial dose was 20 mCi and escalation was in 20-mCi increments. Patients were observed for toxicity and response until death or for a minimum of 1 year after treatment.

RESULTS

We treated 42 patients with (131)I-labeled 81C6 mAb in administered doses up to 180 mCi. Dose-limiting toxicity was observed at doses greater than 120 mCi and consisted of delayed neurotoxicity. None of the patients developed major hematologic toxicity. Median survival for patients with glioblastoma multiforme and for all patients was 69 and 79 weeks, respectively.

CONCLUSION

The MTD for administration of (131)I-labeled 81C6 into the SCRC of newly diagnosed patients with no prior radiation therapy or chemotherapy was 120 mCi. Dose-limiting toxicity was delayed neurologic toxicity. We are encouraged by the survival and toxicity and by the low 2.5% prevalence of debulking surgery for symptomatic radiation necrosis.

Phase I trial of carmustine plus O6-benzylguanine for patients with recurrent or progressive malignant glioma

PURPOSE

The major mechanism of resistance to alkylnitrosourea therapy involves the DNA repair protein O(6)-alkylguanine-DNA alkyltransferase (AGT), which removes chloroethylation or methylation damage from the O(6) position of guanine. O(6)-benzylguanine (O(6)-BG) is an AGT substrate that inhibits AGT by suicide inactivation. We conducted a phase I trial of carmustine (BCNU) plus O(6)-BG to define the toxicity and maximum-tolerated dose (MTD) of BCNU in conjunction with the preadministration of O(6)-BG with recurrent or progressive malignant glioma.

PATIENTS AND METHODS

Patients were treated with O(6)-BG at a dose of 100 mg/m(2) followed 1 hour later by BCNU. Cohorts of three to six patients were treated with escalating doses of BCNU, and patients were observed for at least 6 weeks before being considered assessable for toxicity. Plasma samples were collected and analyzed for O(6)-BG, 8-oxo-O(6)-BG, and 8-oxoguanine concentration.

RESULTS

Twenty-three patients were treated (22 with glioblastoma multiforme and one with anaplastic astrocytoma). Four dose levels of BCNU (13.5, 27, 40, and 55 mg/m(2)) were evaluated, with the highest dose level being complicated by grade 3 or 4 thrombocytopenia and neutropenia. O(6)-BG rapidly disappeared from plasma (elimination half-life = 0. 54 +/- 0.14 hours) and was converted to a longer-lived metabolite, 8-oxo-O(6)-BG (elimination half-life = 5.6 +/- 2.7 hours) and further to 8-oxoguanine. There was no detectable O(6)-BG 5 hours after the start of the O(6)-BG infusion; however, 8-oxo-O(6)-BG and 8-oxoguanine concentrations were detected 25 hours after O(6)-BG infusion. The mean area under the concentration-time curve (AUC) of 8-oxo-O(6)-BG was 17.5 times greater than the mean AUC for O(6)-BG.

CONCLUSION

These results indicate that the MTD of BCNU when given in combination with O(6)-BG at a dose of 100 mg/m(2) is 40 mg/m(2) administered at 6-week intervals. This study provides the foundation for a phase II trial of O(6)-BG plus BCNU in nitrosourea-resistant malignant glioma.

Temozolomide delivered by intracerebral microinfusion is safe and efficacious against malignant gliomas in rats

Intracerebral microinfusion (ICM) is an innovative technique of delivering therapeutic agents throughout large portions of the brain that circumvents the blood-brain barrier, minimizes systemic toxicity, and provides a homogeneous distribution of the infused agent. Temozolomide is a novel methylating agent with proven efficacy against malignant gliomas (MGs) after systemic administration but with dose-limiting myelotoxicity. Because MGs rarely metastasize, systemic drug delivery is unnecessary. Therefore, we evaluated the efficacy and toxicity of ICM with temozolomide in an athymic rat model of human MGs. Treatment of rats by ICM with temozolomide 3 days after intracerebral challenge with D54 human MG xenograft increased median survival by 128% compared with rats treated by ICM with saline, by 113% compared with rats treated with i.p. saline, and by 100% compared with rats treated with i.p. temozolomide (P < 0.001). Delay of treatment until 9 days after tumor challenge still resulted in a 23% increase in median survival in rats treated by ICM of temozolomide compared with rats treated with i.p. temozolomide. In addition, overall, 21.7% of rats treated by ICM with temozolomide survived for > 100 days without clinical or histological evidence of tumor. The dose of temozolomide delivered by ICM in this study was limited only by drug solubility, and no neurological or systemic toxicity could be attributed to ICM with temozolomide. Therefore, ICM of temozolomide may offer significant advantages in the treatment of MGs.

Glioma-associated antigen expression in oligodendroglial neoplasms. Tenascin and epidermal growth factor receptor

Epidermal growth factor receptor (EGFR), its variant, EGFRvIII, and tenascin are glioma-associated antigens that are hyperexpressed by neoplastic glial cells relative to normal brain, making them attractive antigenic targets for immunotherapy. Preliminary surveys indicate that oligodendroglial tumors also produce these proteins, although the exact patterns and degrees of reactivity are not known. In this study we examined the immunoreactivity of tenascin among 50 oligodendroglial tumors, including 25 well-differentiated oligodendrogliomas (WDOs) and 12 glioblastomas (GBMs) exhibiting high proportions of oligodendroglia-like cells. We used well-characterized immunoreagents with defined specificities against the target antigens on formalin-fixed, paraffin-embedded archival tissue. The tumors were graded according to WHO guidelines. Immunoreactivity was reported on a 1-3 scale according to staining intensity multiplied by a 1-3 distribution scale distribution within tumor as focal (1), multifocal (2), and diffuse (3) for both the parenchymal and the perivascular components. Although there is considerable overlap in antigen production among the grades of tumor, this study establishes the production of tenascin and wild-type EGFR (but not EGFR vIII) in oligodendroglial neoplasms and supports the concept that antigen production increases with tumor grade.

Castleman's disease confined to the leptomeninges

We report a rare case of the plasma cell variant of Castleman's disease confined to the leptomeninges in a 42-year-old female. Flow cytometry demonstrated a minor monoclonal kappa light chain population, and conventional Southern blotting confirmed clonal rearrangement of the J(H) immunoglobulin heavy-chain gene. Polymerase chain reaction for Epstein-Barr virus and Kaposi's sarcoma-associated herpes virus was negative. The patient is disease-free five years after surgical resection. To our knowledge, clonal gene rearrangement has not been previously reported in the plasma cell variant of localized intracranial Castleman's disease.

Gliomas of the optic nerve: histological, immunohistochemical (MIB-1 and p53), and MRI analysis

Gliomas of the optic nerve, although typically of pilocytic (WHO grade I) histology, can present within the spectrum of astrocytic neoplasia including glioblastoma (WHO grade IV). In certain cases, histologic features alone make the distinction between pilocytic and diffuse astrocytomas difficult. We reviewed 22 cases of optic nerve gliomas, 19 of which were pilocytic astrocytomas (PA), and 3 of which were diffuse, non-pilocytic astrocytomas. The cases were evaluated for their clinical course, radiographic appearance, histologic grade, and proliferation indices as detected by MIB-1 (Ki-67) and p53 antibodies. Of the 19 PA, 14 showed no tumor growth by magnetic resonance imaging, and had Ki-67 and p53 labeling indices (LI) of < 1%. The other 5 PA exhibited aggressive behavior manifest by marked diffuse infiltrative tumor growth causing death in 2 patients, 1 of whom was diagnosed with neurofibromatosis type 1 (immunoperoxidase and radiographs not available), and marked local growth with an average time to growth of 39.3 months, a Ki-67 LI of 2-3%, and a p53 LI of < 1% in three others. Three of the five aggressive PA histologically demonstrated a finely reticulated pattern, a pattern that appears as an exaggeration or expansion of the normal neuroglia of the optic nerve, and may simulate a diffuse low-grade astrocytoma. Two demonstrated the coarsely reticulated pattern, with the biphasic and microcystic pattern typical of PA. Three diffuse astrocytomas (2 anaplastic astrocytomas and 1 glioblastoma) originated clinically and radiographically from the optic nerve, and revealed a Ki-67 LI of 2-12%, a p53 LI of 2-8%, and an average time to growth of 8 months. We conclude that the majority of PA of the optic nerve are non-aggressive, stabilize radiographically, and have Ki-67 and p53 LI < 1%. However, a subpopulation of PA has a propensity for aggressive behavior, and are identified by a Ki-67 LI of 2-3% and a p53 LI of < 1%. Diffuse astrocytomas have both Ki-67 and p53 LI > 2%. Thus, in cases of aggressive optic nerve tumors in which the histologic review of biopsy material cannot confidently confirm the diagnosis of pilocytic or diffuse fibrillary glioma, a p53 LI of > 1% appears to favor the diagnosis of diffuse astrocytoma.

Characterization of chromosome 17 abnormalities in medulloblastomas

Loss of portions of chromosome 17p, usually through the formation of i(17qp) is a well-known finding in medulloblastomas. Loss of heterozygosity (LOH) studies, however, occasionally demonstrate loss of the more distal portions of 17p, a pattern which is more consistent with a terminal deletion. Here we use a combination of routine karyotyping, fluorescence in situ hybridization (FISH) and LOH studies on four medulloblastoma cell lines and one xenograft to demonstrate the spectrum of chromosome 17 abnormalities which occur in these tumors. Cell line D-556 Med showed a typical dicentric i(17q) and cell line D-721 Med showed two normal copies of chromosome 17 by all methods. Cell line D-425 Med showed loss of terminal 17p by LOH, while the karyotype showed what appeared to be an i(17q). FISH and chromosome 17 painting, however, demonstrated that the abnormal chromosome 17 was actually formed through an unbalanced translocation involving two copies of chromosome 17, with breakpoints at p12 and q11-1, an explanation which reconciled the cytogenetic and LOH findings. Cell line D 581 Med had a terminal deletion at 17p11.2. The finding of two cells with i(17q) in this case by interphase FISH suggests that the terminal deletion arose from breakage of an i(17q). Finally, xenograft D 690 Med showed LOH for regions distal to 17p12, whereas karyotyping, FISH using probes on 17p, and chromosome 17 painting showed two intact copies of chromosome 17. This pattern can be explained by homologous recombination. These data support the concept that the critical deletion of 17p can occur through a variety of mechanisms in the medulloblastoma. The losses may occur through typical i(17q), as well as other mechanisms such as terminal deletions, possibly through breakage of i(17q), unbalanced translocations and homologous recombination.

Intrathecal busulfan treatment of human neoplastic meningitis in athymic nude rats

The current study was designed to evaluate the toxicity and activity of Spartaject Busulfan, a microcrystalline preparation of busulfan, following its intrathecal administration into a nude rat model of human neoplastic meningitis. Animals were treated through permanent indwelling subarachnoid catheters. Human glioma D-456 MG growing in the subarachnoid space was treated with 8.1 micromol of intrathecal Spartaject Busulfan. Single-dose therapy was also subsequently compared with 4 doses of 8.1 and 2.0 micromol busulfan, respectively, against D-456 MG neoplastic meningitis. Additional experiments evaluated a saline control versus 8.1 micromol x 1, 6.2 micromol x 4 and 4.1 micromol x 4, respectively, against D-456 MG. A single dose of 8.1 micromol of intrathecal Spartaject Busulfan resulted in an increase in median survival of 61.7% compared with the saline control. In experiment 2, all busulfan treatments showed increases in median survival of 142.8% (8.1 micromol x 1), 52.3% (2.0 micromol x 4), and 23% (8.1 micromol x 4) (p < 0.001 for all groups) compared with the saline control. These results suggest that a narrow therapeutic dose range for both toxicity and activity has been defined for intrathecal busulfan in the treatment of human neoplastic meningitis in athymic nude rats. Although busulfan has only limited activity against solid tumors, the high doses achievable in the CSF following intrathecal administration coupled with the steep dose-response relationships of alkylating agents, provide rationale for further evaluation of this agent.

Dosimetry and dose-response relationships in newly diagnosed patients with malignant gliomas treated with iodine-131-labeled anti-tenascin monoclonal antibody 81C6 therapy

PURPOSE

The objective of this study was to perform the dosimetry and evaluate the dose-response relationships in newly diagnosed patients with malignant brain tumors treated by direct injections of (131)I-labeled 81C6 monoclonal antibody (MAb) into surgically created resection cavities (SCRCs).

METHODS AND MATERIALS

Absorbed doses to the 2-cm-thick shell as measured from the margins of the resection cavity interface were estimated for 42 patients with primary brain tumors. MR images were used to assess the enhanced-rim volume as a function of time after radiolabeled MAb therapy. Biopsy samples were obtained from 15 patients and 1 autopsy.

RESULTS

The average absorbed dose [range] to the 2-cm shell region was 32 [3-59] Gy. For the endpoint of minimal time to MR contrast enhancement, the optimal absorbed dose and initial dose-rate were 43 +/- 16 Gy and 0. 41 +/- 0.10 Gy/h, respectively. There was a correlation between the absorbed dose and dose rate to the shell region and biopsy outcome (tumor recurrence, radionecrosis, and tumor recurrence and/or radionecrosis). In this Phase I study, the maximum tolerated dose (MTD) was 120 mCi. At this MTD, the estimated average absorbed dose and initial dose rate to the 2-cm shell were 41 [9-89] Gy and 0.51 [0.24-1.13] Gy/h, respectively. These values are in agreement with the optimal values based on the time to MR lesion rim enhancement.

CONCLUSIONS

The average absorbed dose to the 2-cm shell region varied considerably and mainly depended on cavity volume. In future clinical trials, the administered activity of (131)I-labeled 81C6 MAb may be adjusted based on cavity volume in order to deliver the optimal absorbed dose of 43 Gy rather than giving a fixed administered activity.

Parasitic lesion of the insula suggesting cerebral sparganosis: case report

Cerebral sparganosis, a parasitic disease, rarely produces a chronic active inflammatory response in the brain. Clinically and radiographically the process may mimic a neoplasm. We report a 30-year-old man who underwent surgical exploration for a mass in the insular cortex. Histology revealed a densely fibrotic mass heavily infiltrated with plasma cells and lymphocytes, in which were embedded parasitic forms consistent with sparganosis. We describe the MRI appearances and pathologic features. Intracranial mass lesions secondary to sparganosis must be considered in patients with a history of travel to endemic areas, especially Asia.

Comparison of patient age with MR imaging features of gangliogliomas

OBJECTIVE

The purpose of this study was to compare MR imaging features of gangliogliomas in children less than 10 years old with those seen in patients at least 10 years old.

MATERIALS AND METHODS

Our study population consisted of 15 female patients and 10 male patients with a mean age of 20 years. The early childhood group was composed of six children with a mean age of 5.5 years. The older group was composed of 19 patients with a mean age of 25.6 years. We assessed tumor volume, tumor location, percentage of tumor that was cystic, pattern of contrast enhancement, and degree of edema.

RESULTS

The temporal lobe was the most common tumor location in both groups. Mean tumor volume in the early childhood group was 83 cm3, which was significantly larger than the mean tumor volume (9.78 cm3) for the older group (p = 0.001). Cystic tumors were more common in the early childhood group (83%) than in the older group (63%), and the average percentage of cysts in the cystic tumors was much higher in the early childhood group (67%) than in the older group (30%). Contrast enhancement was seen in five of six early childhood tumors and 13 of 16 tumors in older patients. Four of six tumors in the early childhood group and five of 19 tumors in the older patient group had associated edema.

CONCLUSION

The mean tumor volume of gangliogliomas in the early childhood group was significantly larger than that of the older patient group. This finding may be indicative of differences in tumor growth patterns in the two groups, ability of the hemicranium to adjust to mass effect in childhood, or sampling error as a result of a relatively small sample size.

Bone marrow-derived dendritic cells pulsed with tumor homogenate induce immunity against syngeneic intracerebral glioma

To evaluate the efficacy and toxicity of dendritic cell (DC) based therapy for intracerebral gliomas, we utilized a cell line derived from an astrocytoma that arose spontaneously in a VM/Dk mouse. This astrocytoma mirrors human gliomas phenotypically, morphologically and secretes transforming growth factor (TGF)-betas, immunosuppressive cytokines secreted by human gliomas. Systemic vaccination of mice with DCs pulsed with tumor homogenate followed by intracranial tumor challenge produced a > 160% increase in median survival (p = 0.016) compared with mice vaccinated with PBS or unpulsed DCs (p = 0.083). Fifty percent of mice treated with pulsed DCs survived long-term. Immunologic memory was demonstrated by survival of mice rechallenged with tumor. Both cell-mediated and humoral immunity was induced. On histological examination only focal areas of demyelination at the tumor implantation site were present. There was no evidence that autoimmune encephalomyelitis was induced by DC vaccination. Therefore, in a murine model, vaccination with DCs pulsed with glioma tumor homogenate is a safe and effective therapy against a syngeneic glioma located in the immunologically privileged central nervous system (CNS).

Primary central nervous system lymphomas: a 30-year experience at a single institution

Primary central nervous system lymphoma (PCNSL) is a rare disease that has been increasing in frequency. Clinical, histologic, and immunohistochemical data from 64 cases of PCNSL seen at Duke University Medical Center since 1968 were reviewed and tumors were classified using the REAL classification system. Thirty-two patients were male and 32 were female, with a mean age of 57.1 years, ranging from 16 to 82 years. Large B-cell lymphoma represented overwhelming the majority of PCNSL, accounting for 81% of all cases. Phenotypic T-cell lymphomas were rare with only two cases over the course of the study. Epstein-Barr virus was detected only in the immunocompromised patients and was identified in 75% of those immunocompromised patients who were tested. Overall survival was poor with a mean survival of 357 days and median survival of 158 days. One- and three-year survival rates were 29.6% and 7.8%, respectively. Type of treatment, duration of symptoms, site of lesion, and histologic subtype were not significant prognostic indicators, whereas concurrent immunosuppression was the strongest predictor of poor outcome. In AIDS patients (which accounted for 21.9% of the study group), the median survival was 65 days, which was significantly different than that seen in the immunocompetent group of 217 days (P = .001).

A public database for gene expression in human cancers

A public database, SAGEmap, was created as a component of the Cancer Genome Anatomy Project to provide a central location for depositing, retrieving, and analyzing human gene expression data. This database uses serial analysis of gene expression to quantify transcript levels in both malignant and normal human tissues. By accessing SAGEmap (http://www.ncbi.nlm.nih.gov/SAGE) the user can compare transcript populations between any of the posted libraries. As an initial demonstration of the database's utility, gene expression in human glioblastomas was compared with that of normal brain white matter. Of the 47,174 unique transcripts expressed in these two tissues, 471 (1.0%) were differentially expressed by more than 5-fold (P<0.001). Classification of these genes revealed functions consistent with the biological properties of glioblastomas, in particular: angiogenesis, transcription, and cell cycle related genes.

Electron microscopic diagnosis of human flavivirus encephalitis: use of confocal microscopy as an aid

The distinction between intracranial viral infections and inflammatory conditions requiring immunosuppression is important. Although specific laboratory reagents are readily available for some viruses, diagnosis of arbovirus infection is more difficult. Transmission electron microscopy (TEM) theoretically allows identification of viral particles independent of reagent availability, but it has limited sensitivity. We report two cases of human flavivirus encephalitis diagnosed by TEM. Laser scanning confocal microscopy (LSCM) was used in one case to survey unembedded tissue slices for focal abnormalities, from which fragments smaller than 1 mm2 were excised for epoxy embedding. This facilitated TEM identification of intracytoplasmic, budding, 35-40 nm spherical virus particles, confirmed by serology as St. Louis encephalitis. In contrast to mosquitoes and newborn mice, in which high viral loads are associated with minimal tissue responses, these biopsies showed florid angiodestructive inflammation and microgliosis, with rare virions in necrotic perivascular cells and astrocytes. To our knowledge, this represents the first ultrastructural study of St. Louis encephalitis in humans, indicating the potential value of LSCM-aided TEM.

Meningioma of the fourth ventricle

Meningiomas are primary meningeal based tumors of the central nervous system that rarely are located strictly within the fourth ventricle. We report a 72-year-old man operated upon for such a tumor. The pre-operative magnetic resonance images revealed a well circumscribed mass in the fourth ventricle that exhibited a low signal on T1-weighted magnetic resonance images and homogenously enhanced with gadolinium. By light microscopy the tumor was composed of tightly packed spindle cells separated by collagen. Immunohistochemistry showed the tumor cells to be positive for vimentin and epithelial membrane antigen, and negative for glial fibrillary acidic protein. Electron microscopy revealed typical findings of meningioma, including interdigitating cell processes, desmosomes, and intermediate filaments. Although rare, fibroblastic meningioma must be included in the differential diagnosis of a fourth ventricular spindle cell tumor in elderly patients.

Radiotoxicity of systemically administered 211At-labeled human/mouse chimeric monoclonal antibody: a long-term survival study with histologic analysis

PURPOSE

The antitenascin human/mouse chimeric monoclonal antibody labeled with the alpha-particle-emitting radionuclide 211At is of interest as an endoradiotherapeutic agent for the treatment of brain tumors. To facilitate the investigation of 211At-labeled chimeric 81C6 in patients, the long-term radiotoxicity of this radiopharmaceutical has been evaluated.

METHODS AND MATERIALS

Antibody labeling was performed using N-succinimidyl 3-[211At]astato-benzoate. After an initial dose-finding experiment, a second toxicity study was carried out at 4 dose levels in groups of 30 nonthyroid blocked B6C3F1 mice per group (15 males, 15 females). Male mice received either saline or 15-81 kBq/g and females received either saline or 16-83 kBq/g of 211At-labeled antibody. Ten animals (5 males, 5 females) were followed for 6 months and the remainder for 1 year.

RESULTS

The lethal dose in 10% of animals (LD10) for 211At-labeled chimeric 81C6 was 46 kBq/g in females and 102 kBq/g in males. Toxic effects--perivascular fibrosis of the intraventricular septum of the heart, bone marrow suppression, splenic white pulp atrophy, and spermatic maturational delay--generally were confined to a few animals receiving the highest doses of labeled antibody.

CONCLUSIONS

The LD10 of 211At-labeled chimeric 81C6 in this mouse strain was about half that of [211At]astatide. These results establish the preclinical maximum tolerated dose of 211At-labeled chimeric 81C6 and define in the mouse the target organs for toxicity. These studies will be useful for determining starting doses for clinical studies with 211At-labeled chimeric 81C6.

Regional treatment of epidermal growth factor receptor vIII-expressing neoplastic meningitis with a single-chain immunotoxin, MR-1

The incidence of neoplastic meningitis is on the rise. Neoplastic meningitis can result from a direct seeding of the neuraxis by primary brain tumors or by hematogeneous spread of systemic solid tumors. A frequent genetic alteration in primary brain tumors such as gliomas is an in-frame deletion in the epidermal growth factor receptor (EGFR) gene EGFRvIII, which brings together what were normally distant polypeptide sequences in the intact receptor. A novel glycine is formed at the fusion junction, resulting in a unique and tumor-specific target. By using phage display, we have isolated a single-chain antibody specific for the EGFRvIII mutation and expressed it with a modified form of the Pseudomonas exotoxin to form the immunotoxin MR1scFvPE38KDEL (MR-1). The multiple dose toxicity and therapeutic efficacy of MR-1 immunotoxin were tested in an athymic rat model of neoplastic meningitis. The maximally tolerated doses in non-tumor-bearing rats were three doses of 3 microg each. For therapeutic studies, the target was a neoplastic meningitis induced by intrathecal inoculation of the EGFRvIII-expressing human glioma U87MG.deltaEGFR. A dose escalation study compared the survival of three equal doses of 1, 2, and 3 microg of MR-1 immunotoxin with saline or 3 microg of the control immunotoxin specific for the interleukin 2 receptor, anti-Tac. All animals treated with three doses of saline or 3 microg of anti-Tac died, with median survival of 7 and 10 days, respectively. There were 75% (six of eight) long-term survivors in the group treated with three doses of 1 microg and 57% (four of seven) long-term survivors in the groups treated with three doses of either 2 or 3 microg of MR-1 immunotoxin. None of the MR-1 immunotoxin-treated groups reached median survival by the termination of the study at 53 days. Therefore, median survival was estimated to be >53 days, resulting in an estimated increase in median survival of >657% compared with saline and 430% versus anti-Tac. Compartmental therapy with three doses of 2 microg of MR-1 immunotoxin is effective in the treatment of EGFRvIII-expressing neoplastic meningitis. This dose was found to have no clinical or histopathological effects on non-tumor-bearing animals. MR-1 immunotoxin is, therefore, considered specific and safe within its therapeutic window. Phase I clinical trials for tumors invading the intrathecal space that express the EGFRvIII target should be initiated.

Molecular genetic aspects of oligodendrogliomas including analysis by comparative genomic hybridization

Oligodendroglial neoplasms are a subgroup of gliomas with distinctive morphological characteristics. In the present study we have evaluated a series of these tumors to define their molecular profiles and to determine whether there is a relationship between molecular genetic parameters and histological pattern in this tumor type. Loss of heterozygosity (LOH) for 1p and 19q was seen in 17/23 (74%) well-differentiated oligodendrogliomas, in 18/23 (83%) anaplastic oligodendrogliomas, and in 3/8 (38%) oligoastrocytomas grades II and III. LOH for 17p and/or mutations of the TP53 gene occurred in 14 of these 55 tumors. Only one of the 14 cases with 17p LOH/TP53 gene mutation also had LOH for 1p and 19q, and significant astrocytic elements were seen histologically in the majority of these 14 tumors. LOH for 9p and/or deletion of the CDKN2A gene occurred in 15 of these 55 tumors, and 11 of these cases were among the 24 (42%) anaplastic oligodendrogliomas. Comparative genomic hybridization (CGH) identified the majority of cases with 1p and 19q loss and, in addition, showed frequent loss of chromosomes 4, 14, 15, and 18. These findings demonstrate that oligodendroglial neoplasms usually have loss of 1p and 19q whereas astrocytomas of the progressive type frequently contain mutations of the TP53 gene, and that 9p loss and CDKN2A deletions are associated with progression from well-differentiated to anaplastic oligodendrogliomas.

Gliomatosis cerebri: cytologic and autopsy findings in a case involving the entire neuraxis

We describe the case of a 7-year-old girl who was clinically diagnosed as having a pontine glioma based on magnetic resonance imaging studies. Neoplastic cells were identified upon cytologic examination of cerebrospinal fluid. Autopsy studies revealed an anaplastic astrocytoma (WHO grade III) diffusely infiltrating the cerebral hemispheres, brain stem, cerebellum, leptomeninges, and spinal cord to the level of the conus medullaris. The Ki-67 labeling index focally approached 30%. Although many of the neoplastic cells displayed elongated twisted nuclei reminiscent of microglia, these cells stained intensely for glial fibrillary acidic protein, supporting an astrocytic origin. Unusual features of this case of gliomatosis cerebri include involvement of the entire central neuraxis, correlation with pre-mortem lumbar puncture cytology, and a markedly elevated Ki-67 labeling index.

Treatment of neoplastic meningitis with intrathecal temozolomide

Neoplastic meningitis (NM) results from leptomeningeal dissemination of cancers arising within the central nervous system or metastasizing to the leptomeninges from systemic neoplasms. The inability to produce therapeutic drug levels intrathecally (i.t.) with systemic administration and the minimal efficacy of chemotherapeutic agents currently available for direct i.t. use limit therapy. Temozolomide [8-carbamoyl-3-methylimidazo[5,1-d]-1,2,3,5-tetrazin-4([3H])-one] is a novel methylating agent with proven activity against intraparenchymal malignant gliomas (MGs). Insolubility of the standard formulation prevents its efficacious use as an i.t. agent, however. To overcome this obstacle, we have developed a unique microcrystalline formulation of temozolomide with greatly enhanced solubility. Treatment of athymic rats bearing subarachnoid MER- human MG xenografts with four doses of i.t. microcrystalline temozolomide over a 2-week period produced a 142% increase in median survival at individual doses of 2.2 micromol (P = 0.0073) and a >367% increase in median survival at individual doses of 6.8 micromol (P = 0.0015). At the higher dose tested, three of eight rats treated developed no neurological symptoms and had no evidence of residual tumor on histological examination after treatment. Use of this microcrystalline formulation in athymic rats bearing subarachnoid MER+ human MG xenografts increased median survival >132% (P < 0.0058) at both dose levels tested. Toxicity directly attributable to the i.t. administration of microcrystalline temozolomide was exhibited in the highest dose groups only and was limited to small patchy areas of focal demyelination involving <5% of spinal cord long tracks.

Fine-needle aspiration cytology of "ancient" schwannoma

The term "ancient" schwannoma was proposed for a group of neural tumors showing degenerative changes and marked nuclear atypia. Prior to the realization that the observed atypia was a regressive phenomenon, many of these lesions were erroneously diagnosed as sarcomas. Fine-needle aspiration (FNA) cytologic material from five patients is included in this study. Tissue examined histologically included four resected tumors and 18 gauge core biopsies of one tumor. Aspirates of ancient schwannoma showed many of the same features as FNA of regular schwannoma: aggregates of spindled cells with indistinct cytoplasm and elongate nuclei with blunt point ends. The feature unique to these lesions was nuclear pleomorphism, which was identified in all aspirates. Nuclear inclusions were identified in all but one case. Cystic degeneration, xanthomatous changes, and perivascular sclerosis were identified in excised lesions. Ancient schwannomas show most of the FNA features of benign schwannomas but can demonstrate marked nuclear atypia. The FNA features of ancient schwannoma are important to note because of the potential to confuse this lesion with a more serious one such as sarcoma on FNA.

Irinotecan therapy in adults with recurrent or progressive malignant glioma

PURPOSE

To determine the activity, toxicity, and pharmacokinetics of irinotecan (CPT-11, Camptosar; Pharmacia & Upjohn, Kalamazoo, MI) in the treatment of adults with progressive, persistent, or recurrent malignant glioma.

PATIENTS AND METHODS

Patients with progressive or recurrent malignant gliomas were enrolled onto this study between October 1996 and August 1997. CPT-11 was given as a 90-minute intravenous (i.v.) infusion at a dose of 125 mg/m2 once weekly for 4 weeks followed by a 2-week rest, which comprised one course. Plasma concentrations of CPT-11 and its metabolites, SN-38 and SN-38 glucuronide (SN-38G), were determined in a subset of patients.

RESULTS

All 60 patients who enrolled (36 males and 24 females) were treated with CPT-11 and all were assessable for toxicity, response, and survival. Pharmacokinetic data were available in 32 patients. Nine patients (15%; 95% confidence interval, 6% to 24%) had a confirmed partial response, and 33 patients (55%) achieved stable disease lasting more than two courses (12 weeks). Toxicity observed during the study was limited to infrequent neutropenia, nausea, vomiting, and diarrhea. CPT-11, SN-38, and SN-38G area under the plasma concentration-time curves through infinite time values in these patients were approximately 40%, 25%, and 25%, respectively, of those determined previously in patients with metastatic colorectal cancer not receiving antiepileptics or chronic dexamethasone treatment.

CONCLUSION

Response results document that CPT-11, given with a standard starting dose and treatment schedule, has activity in patients with recurrent malignant glioma. However, the low incidence of severe toxicity and low plasma concentrations of CPT-11 and SN-38 achieved in this patient population suggest that concurrent treatment with anticonvulsants and dexamethasone enhances drug clearance.

Malignant supratentorial ganglioglioma (ganglion cell-giant cell glioblastoma): a case report and review of the literature

BACKGROUND

From both epidemiologic and pathologic viewpoints, gangliogliomas exhibiting components of giant cell glioblastomas are extraordinary neoplasms. We report herein the case of a 6-year-old girl who presented initially with a World Health Organization grade IV anaplastic ganglioglioma (a mixed ganglion cell tumor-giant cell glioblastoma). Despite aggressive management, the patient died of disease in a relatively short period.

METHODS

Formalin-fixed, paraffin-embedded tissue blocks were sectioned at 5 microm for histochemical and immunohistochemical analyses. Hematoxylin-eosin-stained sections and immunohistochemically stained sections from the primary and secondary resections were reviewed. Reactivity for glial fibrillary acidic protein, neurofilament protein, synaptophysin, and Ki67 nuclear antigen was evaluated.

RESULTS

Histologically, 2 distinct cell populations were noted on both the primary and secondary resections. The primary resection revealed a neoplasm having a predominant glial component consistent with a glioblastoma. Interspersed were dysmorphic ganglion cells supporting a diagnosis of ganglioglioma. The second resection (following therapy) demonstrated a much more prominent dysmorphic ganglion cell component and a subdued glial component.

CONCLUSION

Although immunohistochemical analysis clearly distinguished the 2 tumor cell populations, the identification of Nissl substance in neurons proved to be equally helpful. Although other cases of grade III gangliogliomas and rare cases of grade IV gangliogliomas have been reported, the present case is exceptional in that, to our knowledge, it is the only report of a patient who presented initially with a composite grade IV ganglioglioma and who was clinically followed up to the time of death. This case allows direct comparison between the histologic findings in a giant cell glioblastoma and a ganglioglioma and documents the aggressive biologic behavior of this complex neoplasm.

Gangliogliomas: characterization by registered positron emission tomography-MR images

OBJECTIVE

The purpose of this study was to correlate 18F-fluorodeoxyglucose positron emission tomography (PET) and MR imaging features of cerebral gangliogliomas before and after PET-MR image registration.

CONCLUSION

After registration of PET and MR images, all six gangliogliomas in our series were shown to have heterogeneous metabolic activity. Areas of hypermetabolic activity were seen in all lesions. In five of the six cases, PET-MR image registration provided information regarding tumor metabolism that was not available on nonregistered hard-copy examinations.

Topotecan treatment of adults with primary malignant glioma. The Brain Tumor Center at Duke

BACKGROUND

Topotecan activity was evaluated for the treatment of malignant glioma.

METHODS

Sixty-three patients with newly diagnosed (n = 25) or recurrent (n = 38) malignant glioma were treated with topotecan [AU: Please verify all dosages here and throughout text.]at a dose of 2.6 mg/m2 over a 72-hour period weekly. Recurrent tumors included glioblastoma multiforme (GBM) (n = 28) and anaplastic astrocytoma (AA) (n = 10). Newly diagnosed tumors included GBM (n = 14), AA (n = 8), and anaplastic oligodendroglioma (n = 3).

RESULTS

Partial responses were observed in 2 of 14 evaluable patients with newly diagnosed GBM, 1 of 8 patients with newly diagnosed AA, 3 of 10 patients with recurrent AA, and none of 28 patients with recurrent GBM. Four patients with recurrent AA and 7 patients with recurrent GBM demonstrated stable disease (range, 8-52 weeks; median, 21 weeks). Toxicity was limited to infrequent National Cancer Institute Common Toxicity Criteria Grade 3 myelosuppression.

CONCLUSIONS

These results suggest that topotecan has modest activity against malignant glioma and continued evaluation of its effectiveness may be warranted when alternative schedules or combination regimens are used.

Diagnostic markers in paediatric medulloblastoma: a Paediatric Oncology Group Study

AIMS

We have reviewed immunohistochemically 17 paediatric medulloblastomas in order to determine if correlations exist that might be useful in subclassifying these tumours.

METHODS AND RESULTS

The patient group included 11 children who had died (mean survival 13 months) and six still alive (followed for up to 10 years). Ten tumours were diffuse and six were nodular (one biopsy had only perivascular tumour). Of the 10 diffuse tumours, three were desmoplastic: of the six nodular tumours, all six were desmoplastic. All 17 tumours were synaptophysin-reactive: three nodular tumours were glial fibrillary acidic protein (GFAP)-reactive in the nodules (two of three S 100-reactive tumours were also GFAP-reactive). MIB-1 labelling indices (LI) ranged from 5 to 80%. Six tumours exhibited at least 1% LI against Tp53 (Mab D07 and/or Mab 1801). Eight cases were 100% bcl2-reactive with nine cases having an LI <80% ('low labelling'). All nine 'low labelling' bcl2 cases were TP53 non-reactive; all six Tp53-reactive cases were bcl2 100% reactive. Six of 10 patients with diffuse medulloblastomas survived 18 months or less while four of 10 are alive up to 10 years. In contrast, five of six patients with nodular neoplasms died within 48 months of diagnosis with one patient followed up for less than 1 year.

CONCLUSIONS

Immunohistochemistry is a useful adjunct in characterizing subsets of paediatric medulloblastomas and confirms that larger co-operative studies may be fruitful in identifying a prognostic utility of a combined histochemical/immunohistochemical analysis on these tumours.

Morphologic and molecular genetic aspects of oligodendroglial neoplasms

Morphologic criteria for diagnosing oligodendrogliomas and for classifying them as well-differentiated (World Health Organization grade II) and anaplastic (World Health Organization grade III) are well recognized. Nevertheless, applying these guidelines to specific cases often reveals discrepancies among different observers. In addition, whether a given tumor also contains an astrocytic component may be debatable. Loss of heterozygosity studies have demonstrated that oligodendroglial neoplasms have a high incidence of loss of the 1p and 19q chromosomal arms. Although loss of heterozygosity for portions of 19q are sometimes seen in astrocytic neoplasms, these tumors seldom show complete loss of 19q accompanied by loss of 1p. Loss of 9p or homozygous deletion of the CDKN2 gene or both are associated with anaplastic oligodendrogliomas, whereas loss of 17p or TP53 gene mutations or both are frequent in astrocytomas, but rare in oligodendrogliomas. These observations suggest that molecular genetic parameters could provide an objective, reproducible framework for classifying oligodendroglial neoplasms.

DNA mismatch repair and O6-alkylguanine-DNA alkyltransferase analysis and response to Temodal in newly diagnosed malignant glioma

PURPOSE

We evaluated the response to Temodal (Schering-Plough Research Institute, Kenilworth, NJ) of patients with newly diagnosed malignant glioma, as well as the predictive value of quantifying tumor DNA mismatch repair activity and O6-alkylguanine-DNA alkyltransferase (AGT).

PATIENTS AND METHODS

Thirty-three patients with newly diagnosed glioblastoma multiforme (GBM) and five patients with newly diagnosed anaplastic astrocytoma (AA) were treated with Temodal at a starting dose of 200 mg/m2 daily for 5 consecutive days with repeat dosing every 28 days after the first daily dose. Immunochemistry for the detection of the human DNA mismatch repair proteins MSH2 and MLH1 and the DNA repair protein AGT was performed with monoclonal antibodies and characterized with respect to percent positive staining.

RESULTS

Of the 33 patients with GBM, complete responses (CRs) occurred in three patients, partial responses (PRs) occurred in 14 patients, stable disease (SD) was seen in four patients, and 12 patients developed progressive disease (PD). Toxicity included infrequent grades 3 and 4 myelosuppression, constipation, nausea, and headache. Thirty tumors showed greater than 60% cells that stained for MSH2 and MLH1, with three CRs, 12 PRs, three SDs, and 12 PDs. Eight tumors showed 60% or less cells that stained with antibodies to MSH2 and/or MLH1, with 3 PRs, 3 SDs, and 2 PDs. Eleven tumors showed 20% or greater cells that stained with an antibody to AGT, with 1 PR, 2 SDs, and 8 PDs. Twenty-five tumors showed less than 20% cells that stained for AGT, with 3 CRs, 12 PRs, 4 SDs, and 6 PDs.

CONCLUSION

These results suggest that Temodal has activity against newly diagnosed GBM and AA and warrants continued evaluation of this agent. Furthermore, pretherapy analysis of tumor DNA mismatch repair and, particularly, AGT protein expression may identify patients in whom tumors are resistant to Temodal.

Intradural spinal teratoma: evidence for a dysembryogenic origin. Report of four cases

Intradural spinal teratoma is a rare tumor that can be associated with dysraphic defects. Although the origin of these tumors is traditionally thought to be secondary to primordial germ cells misplaced early in embryogenesis, the pathogenesis of intraspinal teratoma remains unclear. The authors present a series of patients in whom an intradural teratoma arose at the same site as a developmental spinal cord abnormality, including a split cord malformation, myelomeningocele, and lipomyelomeningocele. It is postulated that these lesions were the result of a dysembryogenic mechanism and were not neoplastic.

Phase I trial of O6-benzylguanine for patients undergoing surgery for malignant glioma

PURPOSE

The major mechanism of resistance to alkylnitrosourea therapy is the DNA repair protein O6-alkylguanine-DNA alkyltransferase (AGT), which removes chlorethylation or methylation damage from the O6-position of guanine. O6-benzylguanine (O6-BG) is an AGT substrate that inhibits AGT by suicide inactivation. We conducted a phase I trial to define the presurgical dose required for depletion of tumor AGT activity in patients with malignant glioma.

MATERIALS AND METHODS

Patients were to be treated 18 hours before craniotomy with intravenous doses that ranged between 40 and 100 mg/m2 given over 1 hour. Resected tumor was snap-frozen in liquid nitrogen and AGT activity analyzed by high-pressure liquid chromatography (HPLC). Up to 13 patients were treated at a specific dose of O6-BG, with a target end point of > or = 11 of 13 patients with undetectable tumor AGT levels (< 10 fmol/mg protein).

RESULTS

Thirty patients with malignant gliomas were enrolled, with 11 of 11 patients treated at 100 mg/m2 O6-BG demonstrating tumor AGT levels less than 10 fmol/mg protein. No toxicity was noted in any patient treated.

CONCLUSION

These results indicate that 100 mg/m2 of O6-BG can maintain tumor AGT levels less than 10 fmol/mg protein for at least 18 hours after treatment, a time interval in which bis(2-chloroethyl)nitrosourea (BCNU)-induced chloroethyl adducts are fully converted into interstrand cross-links. A 100-mg/m2 dose of O6-BG will be used in combination with BCNU in another phase I trial designed to determine the maximal-tolerated dose of BCNU.

Ependymomas: MIB-1 proliferation index and survival

The biologic behavior of ependymomas is highly variable, and its correlation with histologic features is at best imprecise. This retrospective study attempted to correlate the malignant histologic characteristics of ependymomas with MIB-1 proliferation index and survival. Biopsy and resection specimens taken from 34 patients who received treatment 1972 to 1996 were histologically examined. The patients' ages range was 1 to 59 years. The histologic specimens were assessed for anaplastic features (necrosis, mitosis, vascular proliferation, cellular pleomorphism, and overlapping of nuclei) and an MIB-1 (Ki-67 antigen) proliferation index was also determined. The overall median MIB-1 proliferation index was 7.8% (range 0.1 - 62.5%). An MIB-1 of 20% was significant for a decrease in survival (RR = 5.7) (p = 0.0013). The median MIB-1 for patients < 20 years old was 20.6% with range (0.1, 43%), while that for patients > 20 years was 5.1% (range 0.2, 9.4%) (KW p = 0.055). Three of 5 histological features evaluated were significantly associated with outcome: > 5 mitotic figures per high-power field, necrosis, and vascular proliferation, but not nuclear overlap or pleomorphism. All pathologic factors except pleomorphism were significantly related to the MIB-1 proliferation index. In brief, our data support the association of poor prognoses in ependymomas with young age, the presence of three to four anaplastic histologic features, and an MIB-1 proliferation index > 20%.

Papillary glioneuronal tumor: a new variant of mixed neuronal-glial neoplasm

We describe the clinicopathologic features of nine cases of a unique papillary glioneuronal tumor (PGNT) exhibiting astrocytic as well as extensive and varied neuronal differentiation. The four male and five female patients studied ranged in age from 11 to 52 years (mean 27.7 years). They either presented with mild neurologic symptoms or were asymptomatic. Magnetic resonance imaging showed demarcated cystic, 1.5-cm to 7-cm contrast-enhancing masses; five involved the temporal lobe, two the parietal, and two the frontal. All but one were totally resected. No recurrence was noted despite a follow-up period of 3 years. Two microscopic components were evident: 1) compact pseudopapillae composed of hyalinized vessels covered by a single layer of glial fibrillary acid protein (GFAP)-positive astrocytes and 2) synaptophysin-positive neuronal cells of varying size, including neurocytes, ganglioid cells, and ganglion cells within neuropil. Immunostains for chromogranin-A were negative, as was in situ hybridization for chromogranin-A mRNA. Ultrastructurally, neuronal cells featured microtubule-containing processes and aberrant synaptic terminals, but dense core granules were rare. Overall, cellularity was moderate and atypia was minimal. No mitotic activity or necrosis was noted. The proportions of the two components varied, but essential morphologic findings were identical in all cases. In that the clinical, radiographic, and morphologic characteristics of PGNT are distinctive, it appears to represent a previously undescribed form of mixed neuronal-glial tumor of the central nervous system.