Caterina Giannini

Inflammatory cortical demyelination in early multiple sclerosis

BACKGROUND Cortical disease has emerged as a critical aspect of the pathogenesis of multiple sclerosis, being associated with disease progression and cognitive impairment. Most studies of cortical lesions have focused on autopsy findings in patients with long-standing, chronic, progressive multiple sclerosis, and the noninflammatory nature of these lesions has been emphasized. Magnetic resonance imaging studies indicate that cortical damage occurs early in the disease. METHODS We evaluated the prevalence and character of demyelinating cortical lesions in patients with multiple sclerosis. Cortical tissues were obtained in passing during biopsy sampling of white-matter lesions. In most cases, biopsy was done with the use of stereotactic procedures to diagnose suspected tumors. Patients with sufficient cortex (138 of 563 patients screened) were evaluated for cortical demyelination. Using immunohistochemistry, we characterized cortical lesions with respect to demyelinating activity, inflammatory infiltrates, the presence of meningeal inflammation, and a topographic association between cortical demyelination and meningeal inflammation. Diagnoses were ascertained in a subgroup of 77 patients (56%) at the last follow-up visit (at a median of 3.5 years). RESULTS Cortical demyelination was present in 53 patients (38%) (104 lesions and 222 tissue blocks) and was absent in 85 patients (121 tissue blocks). Twenty-five patients with cortical demyelination had definite multiple sclerosis (81% of 31 patients who underwent long-term follow-up), as did 33 patients without cortical demyelination (72% of 46 patients who underwent long-term follow-up). In representative tissues, 58 of 71 lesions (82%) showed CD3+ T-cell infiltrates, and 32 of 78 lesions (41%) showed macrophage-associated demyelination. Meningeal inflammation was topographically associated with cortical demyelination in patients who had sufficient meningeal tissue for study. CONCLUSIONS In this cohort of patients with early-stage multiple sclerosis, cortical demyelinating lesions were frequent, inflammatory, and strongly associated with meningeal inflammation. (Funded by the National Multiple Sclerosis Society and the National Institutes of Health.).

A t(1;19)(q10;p10) Mediates the Combined Deletions of 1p and 19q and Predicts a Better Prognosis of Patients with Oligodendroglioma

Combined deletion of chromosomes 1p and 19q is associated with improved prognosis and responsiveness to therapy in patients with anaplastic oligodendroglioma. The deletions usually involve whole chromosome arms, suggesting a t(1;19)(q10;p10). Using stem cell medium, we cultured a few tumors. Paraffin-embedded tissue was obtained from 21 Mayo Clinic patients and 98 patients enrolled in 2 North Central Cancer Treatment Group (NCCTG) low-grade glioma trials. Interphase fusion of CEP1 and 19p12 probes detected the t(1;19). 1p/19q deletions were evaluated by fluorescence in situ hybridization. Upon culture, one oligodendroglioma contained an unbalanced 45,XX,t(1;19)(q10;p10). CEP1/19p12 fusion was observed in all metaphases and 74% of interphase nuclei. Among Mayo Clinic oligodendrogliomas, the prevalence of fusion was 81%. Among NCCTG patients, CEP1/19p12 fusion prevalence was 55%, 47%, and 0% among the oligodendrogliomas, mixed oligoastrocytomas, and astrocytomas, respectively. Ninety-one percent of NCCTG gliomas with 1p/19q deletion and 12% without 1p/19q deletion had CEP1/19p12 fusion (P < 0.001, chi(2) test). The median overall survival (OS) for all patients was 8.1 years without fusion and 11.9 years with fusion (P = 0.003). The median OS for patients with low-grade oligodendroglioma was 9.1 years without fusion and 13.0 years with fusion (P = 0.01). Similar significant median OS differences were observed for patients with combined 1p/19q deletions. The absence of alterations was associated with a significantly shorter OS for patients who received higher doses of radiotherapy. Our results strongly suggest that a t(1;19)(q10;p10) mediates the combined 1p/19q deletion in human gliomas. Like combined 1p/19q deletion, the 1;19 translocation is associated with superior OS and progression-free survival in low-grade glioma patients.

Glioma Groups Based on 1p/19q, IDH, and TERT Promoter Mutations in Tumors

BACKGROUND The prediction of clinical behavior, response to therapy, and outcome of infiltrative glioma is challenging. On the basis of previous studies of tumor biology, we defined five glioma molecular groups with the use of three alterations: mutations in the TERT promoter, mutations in IDH, and codeletion of chromosome arms 1p and 19q (1p/19q codeletion). We tested the hypothesis that within groups based on these features, tumors would have similar clinical variables, acquired somatic alterations, and germline variants. METHODS We scored tumors as negative or positive for each of these markers in 1087 gliomas and compared acquired alterations and patient characteristics among the five primary molecular groups. Using 11,590 controls, we assessed associations between these groups and known glioma germline variants. RESULTS Among 615 grade II or III gliomas, 29% had all three alterations (i.e., were triple-positive), 5% had TERT and IDH mutations, 45% had only IDH mutations, 7% were triple-negative, and 10% had only TERT mutations; 5% had other combinations. Among 472 grade IV gliomas, less than 1% were triple-positive, 2% had TERT and IDH mutations, 7% had only IDH mutations, 17% were triple-negative, and 74% had only TERT mutations. The mean age at diagnosis was lowest (37 years) among patients who had gliomas with only IDH mutations and was highest (59 years) among patients who had gliomas with only TERT mutations. The molecular groups were independently associated with overall survival among patients with grade II or III gliomas but not among patients with grade IV gliomas. The molecular groups were associated with specific germline variants. CONCLUSIONS Gliomas were classified into five principal groups on the basis of three tumor markers. The groups had different ages at onset, overall survival, and associations with germline variants, which implies that they are characterized by distinct mechanisms of pathogenesis. (Funded by the National Institutes of Health and others.).

Variants in the CDKN2B and RTEL1 regions are associated with high-grade glioma susceptibility.

The causes of glioblastoma and other gliomas remain obscure. To discover new candidate genes influencing glioma susceptibility, we conducted a principal component–adjusted genome-wide association study (GWAS) of 275,895 autosomal variants among 692 adult high-grade glioma cases (622 from the San Francisco Adult Glioma Study (AGS) and 70 from the Cancer Genome Atlas (TCGA)) and 3,992 controls (602 from AGS and 3,390 from Illumina iControlDB (iControls)). For replication, we analyzed the 13 SNPs with P < 10−6 using independent data from 176 high-grade glioma cases and 174 controls from the Mayo Clinic. On 9p21, rs1412829 near CDKN2B had discovery P = 3.4 × 10−8, replication P = 0.0038 and combined P = 1.85 × 10−10. On 20q13.3, rs6010620 intronic to RTEL1 had discovery P = 1.5 × 10−7, replication P = 0.00035 and combined P = 3.40 × 10−9. For both SNPs, the direction of association was the same in discovery and replication phases.

Primary central nervous system vasculitis: analysis of 101 patients

To analyze the clinical findings, response to therapy, outcome, and incidence of primary central nervous system vasculitis (PCNSV) in a large cohort from a single center

International Society of Neuropathology‐Haarlem Consensus Guidelines for Nervous System Tumor Classification and Grading

Major discoveries in the biology of nervous system tumors have raised the question of how non‐histological data such as molecular information can be incorporated into the next World Health Organization (WHO) classification of central nervous system tumors. To address this question, a meeting of neuropathologists with expertise in molecular diagnosis was held in Haarlem, the Netherlands, under the sponsorship of the International Society of Neuropathology (ISN). Prior to the meeting, participants solicited input from clinical colleagues in diverse neuro‐oncological specialties. The present “white paper” catalogs the recommendations of the meeting, at which a consensus was reached that incorporation of molecular information into the next WHO classification should follow a set of provided “ISN‐Haarlem” guidelines. Salient recommendations include that (i) diagnostic entities should be defined as narrowly as possible to optimize interobserver reproducibility, clinicopathological predictions and therapeutic planning; (ii) diagnoses should be “layered” with histologic classification, WHO grade and molecular information listed below an “integrated diagnosis”; (iii) determinations should be made for each tumor entity as to whether molecular information is required, suggested or not needed for its definition; (iv) some pediatric entities should be separated from their adult counterparts; (v) input for guiding decisions regarding tumor classification should be solicited from experts in complementary disciplines of neuro‐oncology; and (iv) entity‐specific molecular testing and reporting formats should be followed in diagnostic reports. It is hoped that these guidelines will facilitate the forthcoming update of the fourth edition of the WHO classification of central nervous system tumors.

Patient tumor EGFR and PDGFRA gene amplifications retained in an invasive intracranial xenograft model of glioblastoma multiforme

We have previously described a panel of serially transplantable glioblastoma multiforme xenograft lines established by direct subcutaneous injection of patient tumor tissue in the flanks of nude mice. Here we report the characterization of four of these lines with respect to their histopathologic, genetic, and growth properties following heterotopic-to-orthotopic (flank-to-intracranial) transfer. Cells from short-term cultures, established from excised flank xenografts, were harvested and injected into the brains of nude mice (10(6) cells per injection). The intracranial tumors generated from these injections were all highly mitotic as well as highly invasive, but they lacked necrotic features in most instances and failed to show endothelial cell proliferation in all instances. For mice receiving injections from a common explant culture, tumor intracranial growth rate was consistent, as indicated by relatively narrow ranges in survival time. In contrast to the loss of epidermal growth factor receptor gene (EGFR) amplification in cell culture, high-level amplification and overexpression of EGFR were retained in intracranial tumors established from two EGFR-amplified flank tumors. A third intracranial tumor retained patient tumor amplification and high-level expression of platelet-derived growth factor receptor alpha gene. Because the heterotopic-to-orthotopic transfer and propagation of glioblastoma multiforme preserves the receptor tyrosine kinase (RTK) gene amplification of patient tumors, this approach should facilitate investigations for determining the extent to which RTK amplification status influences tumor response to RTK-directed therapies. The fact that such studies were carried out by using an invasive tumor model in an anatomically appropriate context should ensure a rigorous preclinical assessment of agent efficacy.

Pathologic alterations in the diabetic neuropathies of humans : A review

Pathologic study of nerve tissue is especially useful for the recognition of interstitial events such as inflammation or vascular alterations that cannot be inferred from clinical or electrophysiologic findings and may provide insight into an underlying mechanism or cause. Considerable variation in the natural history and pathologic alterations among diabetic neuropathies suggests that they are heterogeneous. For diabetic polyneuropathy, two mechanisms need to be considered. The first assumes that hyperglycemia induces metabolic derangements that directly affect Schwann cells (or myelin), nodes of Ranvier, or axons. The second assumes that hyperglycemia and metabolic derangement affect the structure and function of endoneurial microvessels, which then induce fiber changes by altering the blood-nerve barrier, inducing hypoxia or ischemia, or by unknown mechanisms. In proximal diabetic neuropathy, there is increasing evidence that the characteristic lesion is an inflammatory (immune) vasculitis that induces ischemic nerve fiber degeneration. Truncal radiculopathy may be due to an inflammatory polyganglionopathy. In cranial nerve III neuropathy, the monophasic course and the pathologic alterations of ischemia suggest that localized vasculitis should be excluded in future cases. Many upper limb mononeuropathies in diabetes mellitus are from carpal tunnel syndrome or cubital tunnel syndrome. Repetitive shear forces, anatomic factors, and excessive stiffness of connective tissues may cause mononeuropathies.

Phase II Trial of Vorinostat in Recurrent Glioblastoma Multiforme: A North Central Cancer Treatment Group Study

PURPOSE Vorinostat, a histone deacetylase inhibitor, represents a rational therapeutic target in glioblastoma multiforme (GBM). PATIENTS AND METHODS Patients with recurrent GBM who had received one or fewer chemotherapy regimens for progressive disease were eligible. Vorinostat was administered at a dose of 200 mg orally twice a day for 14 days, followed by a 7-day rest period. RESULTS A total of 66 patients were treated. Grade 3 or worse nonhematologic toxicity occurred in 26% of patients and consisted mainly of fatigue (17%), dehydration (6%), and hypernatremia (5%); grade 3 or worse hematologic toxicity occurred in 26% of patients and consisted mainly of thrombocytopenia (22%). Pharmacokinetic analysis showed lower vorinostat maximum concentration and area under the curve (0 to 24 hours) values in patients treated with enzyme-inducing anticonvulsants, although this did not reach statistical significance. The trial met the prospectively defined primary efficacy end point, with nine of the first 52 patients being progression-free at 6 months. Median overall survival from study entry was 5.7 months (range, 0.7 to 28+ months). Immunohistochemical analysis performed in paired baseline and post-vorinostat treatment samples in a separate surgical subgroup of five patients with recurrent GBM showed post treatment increase in acetylation of histones H2B and H4 (four of five patients) and of histone H3 (three of five patients). Microarray RNA analysis in the same samples showed changes in genes regulated by vorinostat, such as upregulation of E-cadherin (P = .02). CONCLUSION Vorinostat monotherapy is well tolerated in patients with recurrent GBM and has modest single-agent activity. Histone acetylation analysis and RNA expression profiling indicate that vorinostat in this dose and schedule affects target pathways in GBM. Additional testing of vorinostat in combination regimens is warranted.

The relationship between six-month progression-free survival and 12-month overall survival end points for phase II trials in patients with glioblastoma multiforme

Common end points for phase II trials in patients with glioblastoma multiforme (GBM) are six-month progression-free survival (PFS6) and 12-month overall survival (OS12). OS12 can be accurately measured but may be confounded with subsequent therapies upon progression, whereas the converse is true for PFS6. Our goal was to assess the relationship between these end points separately for phase II trials in patients with newly diagnosed GBM and patients with recurrent GBM. Data were pooled from 11 North Central Cancer Treatment Group trials for patients with newly diagnosed GBM (n = 1348). All patients received radiotherapy and pharmaceutical therapy (before, during, or after radiotherapy). Data were pooled from 16 trials that used various pharmaceuticals in treating patients for recurrent GBM (n = 345). All trial regimens were declared nonefficacious by predefined criteria. Overall per-patient concordance was estimated with a kappa statistic. The relationship between OS12 and PFS6 across study arms was assessed by weighted linear regression and Pearsons correlation. Simulation was used to determine the agreement of study outcomes when using PFS6 versus OS12 end points. Cox models with progression status as a time-dependent variable and Kaplan-Meier estimators were used to ascertain the association between progression-free survival status and overall survival. At present, 97% of the patients with newly diagnosed GBM and 95% of those with recurrent GBM have died. The PFS6 and OS12 were 43% and 41%, respectively, for patients with newly diagnosed disease and 9% and 14% for patients with recurrent disease. There was only moderate concordance between the end points on both the patient level and the study level. For the simulation studies, we established phase II efficacy criteria for each end point by using the pooled estimates of OS12 (PFS6) as historical controls. The study decisions made using PFS6 and OS12 were in agreement 88% and 90% of the time for the trials of newly diagnosed and recurrent disease, respectively. Finally, there was a strong association between progression-free survival status and overall survival. PFS6 seems to be a reasonable end point for phase II trials in patients with recurrent glioblastoma.