Aggressive pituitary neuroendocrine tumors: current practices, controversies, and perspectives, on behalf of the EANS skull base section.

Aggressive pituitary neuroendocrine tumors (APT) account for 10% of pituitary tumors. Their management is a rapidly evolving field of clinical research and has led pituitary teams to shift toward a neuro-oncological-like approach. The new terminology "Pituitary neuroendocrine tumors" (PitNet) that was recently proposed to replace "pituitary adenomas" reflects this change of paradigm. In this narrative review, we aim to provide a state of the art of actual knowledge, controversies, and recommendations in the management of APT. We propose an overview of current prognostic markers, including the recent five-tiered clinicopathological classification. We further establish and discuss the following recommendations from a neurosurgical perspective: (i) surgery and multi-staged surgeries (without or with parasellar resection in symptomatic patients) should be discussed at each stage of the disease, because it may potentialize adjuvant medical therapies; (ii) temozolomide is effective in most patients, although 30% of patients are non-responders and the optimal timeline to initiate and interrupt this treatment remains questionable; (iii) some patients with selected clinicopathological profiles may benefit from an earlier local radiotherapy and/or chemotherapy; (iv) novel therapies such as VEGF-targeted therapies and anti-CTLA-4/anti-PD1 immunotherapies are promising and should be discussed as 2nd or 3rd line of treatment. Finally, whether neurosurgeons have to operate on "pituitary adenomas" or "PitNets," their role and expertise remain crucial at each stage of the disease, prompting our community to deal with evolving concepts and therapeutic resources.

BRAF mutation and anaplasia may be predictive factors of progression-free survival in adult pleomorphic xanthoastrocytoma.

BACKGROUND: Pleomorphic xanthoastrocytoma (PXA) is a rare, low-grade glioma that frequently occurs in pediatric patients. OBJECTIVE: To analyze adult patients diagnosed with PXA and to search for pathological and molecular markers of diagnosis and prognosis. METHODS: We retrospectively included patients older than 16 years with PXA who were referred to our institution between October 2003 and September 2013. All pathological diagnoses were reviewed by a neuropathologist. Histological characteristics and immunostaining of GFAP, OLIG2, neurofilament, CD34, Ki67, p53, p16, and IDH1 R132H were analyzed. The following molecular alterations were analyzed: mutations of IDH1/2, BRAF and the histone H3.3 and the EGFR amplification. Clinical data, treatment modalities, and patient outcome were recorded. RESULTS: We identified 16 adult patients with reviewed PXA diagnosis. No IDH neither histone H3.3 mutations were found; BRAF V600E mutation was recorded in six patients. Ten patients presented with anaplastic features. BRAF mutations were associated with lower Ki67, OLIG2 expression, and lack of p16 expression. Median PFS and OS were 41.5 months (95% CI: 11.4-71.6) and 71.4 months (95% CI: 15.5-127.3), respectively. BRAF mutation tended to be associated with greater PFS (p = 0.051), whereas anaplastic features were associated with minimal PFS (p = 0.042). CONCLUSION: PXA in adults PXA may present features distinct from pediatric PXA. Anaplastic features and BRAF mutation may potentially identify specific subgroups with distinct prognoses.

Postoperative follow-up of Cushing's disease using cortisol, desmopressin and coupled dexamethasone-desmopressin tests: a head-to-head comparison.

OBJECTIVE: Predicting the outcome of patients operated on for Cushing's disease (CD) is a challenging task. Our objective was to assess the accuracy of immediate postsurgical plasma cortisol, desmopressin test and the coupled dexamethasone-desmopressin test (CDDT) as predictors of outcome. DESIGN AND PATIENTS: Sixty-seven patients with initial remission and a minimal postsurgical follow-up greater than 18 months were included in this retrospective bicentre study. MEASUREMENTS: Follow-up included 3-6 months followed by yearly 24-h urinary-free cortisol, ACTH and cortisol plasmatic levels, a 1-mg overnight dexamethasone suppression test (1-mg DST), desmopressin test and the CDDT. ROC curves were performed to define the optimal threshold of immediate postsurgical cortisol level and 3- to 6-month desmopressin test and CDDT, as predictors of final outcome in comparison with classical biological markers of recurrence. RESULTS: Eleven patients presented recurrence. The patient's median follow-up was 52 months (range, 18-180). As early predictors of outcome, immediate postsurgical plasma cortisol level <35 nmol/l predicted the lack of recurrence with 93% negative predictive value (NPV), whereas predictive positive value (PPV) was 25%. During the follow-up, the CDDT was more precise than the desmopressin test in predicting the lack of recurrence (100% NPV) when performed in the first 3 years after surgery. Positivity of the CDDT was defined based on ROC curves by ACTH and cortisol increments >50%. The CDDT was highly reproducible, as the same response was observed every year in 91% of the patients. CONCLUSIONS: Adding the CDDT the first 3 years after surgery to immediate postsurgical cortisol evaluation should allow obtaining an optimal follow-up management of patients operated for Cushing's disease.

Patients with brain metastases from colorectal cancer are not condemned.

BACKGROUND: Brain metastases (BMs) from colorectal cancer are rare (2-3%). They usually occur in advanced stages of the disease and their prognosis is poor. The aim of this study was to assess the impact of surgical resection of BMs from colorectal cancer in terms of overall survival. PATIENTS AND METHODS: A retrospective bi-centric study included all patients with resected BMs from primary colorectal adenocarcinoma from 1998 to 2009. RESULTS: Twenty-eight patients [13 males, median: 62 (range: 44-86) years old) were included. Fifteen patients presented with other metastatic sites (lung, liver). BMs were metachronous in 16/28 (57%) of patients [median: 19 months (range: 7-97)]. Median overall survival reached 12 months. Brain recurrences occurred in 32% of patients and were treated by curative intent in 5/9 cases. CONCLUSION: When indicated, an aggressive management based on surgical resection of BMs from colorectal cancer, must be performed, in order to improve overall survival to at least 12 months.

The expansion of the microbiological spectrum of brain abscesses with use of multiple 16S ribosomal DNA sequencing.

Background. Brain abscess is commonly treated using empirically prescribed antibiotics. Thus, a comprehensive study of bacterial organisms associated with brain abscess is essential to define the best empirical treatment for this life-threatening condition. Methods. We prospectively compared cultures to single and multiple sequenced 16S ribosomal DNA polymerase chain reaction amplifications (by cloning and/or pyrosequencing) of cerebral abscesses in 20 patients from 2 hospitals in Marseilles, France, during the period January 2005 through December 2007. Results. The obtained cultures identified significantly fewer types of bacteria (22 strains) than did molecular testing (72 strains; P = .017, by analysis of variance test). We found that a patient could exhibit as many as 16 different bacterial species in a single abscess. The obtained cultures identified 14 different species already known to cause cerebral abscess. Single sequencing performed poorly, whereas multiple sequencing identified 49 species, of which 27 had not been previously reported in brain abscess investigations and 15 were completely unknown. Interestingly, we observed 2 patients who harbored Mycoplasma hominis (an emerging pathogen in this situation) and 3 patients who harbored Mycoplasma faucium, which, to our knowledge, has never been reported in literature. Conclusions. Molecular techniques dramatically increased the number of identified agents in cerebral abscesses. Mycoplasma species are common and should be detected in this situation. These findings led us to question the accuracy of the current empirical treatment of brain abscess.

Gs alpha overexpression and loss of Gs alpha imprinting in human somatotroph adenomas: association with tumor size and response to pharmacologic treatment.

Gs alpha, the alpha-subunit of the heterotrimeric GTP-binding protein, is coded from the GNAS gene, which is imprinted in a tissue-specific manner. Gs alpha is paternally silenced in normal pituitary, but Gs alpha imprinting relaxation is found in some tumoral tissue. In addition, Gs alpha mRNA levels are high in some somatotroph adenomas not bearing the active Gs alpha mutant, the gsp oncogene. In this study, the impact of loss of imprinting on Gs alpha expression level and on tumoral phenotype has been investigated. We compared the expression and imprinting of 4 transcripts of GNAS locus (NESP55, XL alpha s, exon 1A, Gs alpha) of 60 somatotroph adenomas with those of 23 lactotroph adenomas. The paternal and maternal transcripts were quantified using allele-specific real-time PCR and FokI polymorphism. Moreover, the methylation of exon 1A DMR was analyzed. As is the case for the gsp oncogene, high Gs alpha expression in gsp- tumors was associated with smaller tumor size and better octreotide sensitivity. A strong imprinting relaxation (percentage of paternal Gs alpha expression >or=7.5%) was found only in gsp- tumors. The loss of Gs alpha imprinting was associated with a decrease in exon 1A mRNA expression. Unexpectedly, the methylation status of exon 1A DMR was not modified in relaxed tumors. Maternal Gs alpha mRNA level decreased with exon 1A level, and consequently the loss of Gs alpha imprinting did not induce the expected Gs alpha overexpression. Finally, XL alpha s mRNA level correlated with that of paternal Gs alpha and of NESP55 showing the complexity of gene regulation in the GNAS locus.

Open kyphoplasty for management of metastatic and severe osteoporotic spinal fracture. Technical note.

OBJECT: Elderly patients in poor general health frequently suffer vertebral body (VB) fractures due to osteoporosis or vertebral metastatic lesions. Kyphoplasty and vertebroplasty have become the standard treatment for these types of fractures. In certain conditions that cause local kyphosis, such as spinal cord compression due to a metastatic epidural tumor or the shortening of the spinal canal secondary to vertebral compression, the surgical treatment should provide decompression and stabilization during a short intervention. In this study the authors evaluated a surgical technique that frequently combines a same-session surgical decompression, such as a laminectomy, and posterior instrumentation-assisted stabilization during the same open intervention in which the VB is stabilized by kyphoplasty. METHODS: During an 18-month period, the authors treated 18 patients with VB fractures according to this protocol: 14 patients with vertebral metastatic lesions and four with osteoporosis. The patients' mean age was 60 years. All suffered severe pain preoperatively (mean visual analog scale [VAS] score of 7). Fourteen of the 18 patients suffered a neurological deficit. Twenty-three vertebral levels were treated; in 15 patients it was necessary to place posterior instrumentation. The mean duration of the intervention was 90 minutes. Pain in all patients improved 3 days after the intervention, and the mean VAS score decreased to 2. Patients with a neurological dysfunction improved. The mean quantity of injected cement for the kyphoplasty procedure was 7 ml. The mean duration of hospitalization was 7 days. Neuroimaging revealed cement leaks in two cases: one into the disc interspace and one anteriorly into the fractured part of the vertebra. After the intervention, most patients with metastatic lesions underwent radiotherapy. No procedure-related complications occurred. CONCLUSIONS: This procedure allows decompression of the spinal cord, consolidation of the VB and thus a stabilization of the vertebral column, and may provide an alternative treatment to invasive VB excision in patients in poor general health.

Large-scale expression study of human mesial temporal lobe epilepsy: evidence for dysregulation of the neurotransmission and complement systems in the entorhinal cortex.

Human mesial temporal lobe epilepsies (MTLE) are the most frequent form of partial epilepsies and display frequent pharmacoresistance. The molecular alterations underlying human MTLE remain poorly understood. A two-step transcriptional analysis consisting in cDNA microarray experiments followed by quantitative RT-PCR validations was performed. Because the entorhinal cortex (EC) plays an important role in the pathophysiology of the MTLE and usually discloses no detectable or little cell loss, resected EC and each corresponding lateral temporal neocortex (LTC) of MTLE patients were used as the source of disease-associated and control RNAs, respectively. Six genes encoding (i) a serotonin receptor (HTR2A) and a neuropeptide Y receptor type 1 (NPY1R), (ii) a protein (FHL2) associating with the KCNE1 (minK) potassium channel subunit and with presenilin-2 and (iii) three immune system-related proteins (C3, HLA-DR-gamma and CD99), were found consistently downregulated or upregulated in the EC of MTLE patients as compared with non-epileptic autopsy controls. Quantitative western blot analyses confirmed decreased expression of NPY1R in all eight MTLE patients tested. Immunohistochemistry experiments revealed the existence of a perivascular infiltration of C3 positive leucocytes and/or detected membrane attack complexes on a subset of neurons, within the EC of nine out of eleven MTLE patients. To summarize, a large-scale microarray expression study on the EC of MTLE patients led to the identification of six candidate genes for human MTLE pathophysiology. Altered expression of NPY1R and C3 was also demonstrated at the protein level. Overall, our data indicate that local dysregulation of the neurotransmission and complement systems in the EC is a frequent event in human MTLE.

Lentiviral vectors efficiently transduce human gonadotroph and somatotroph adenomas in vitro. Targeted expression of transgene by pituitary hormone promoters.

Despite important advances in human therapeutics, no specific treatment for both non-functioning gonadotroph and resistant somatotroph adenomas is available. Gene transfer by viral vectors can be considered as a promising way to achieve a specific and efficient treatment. Here we show the possibility of efficient gene transfer in human pituitary adenoma cells in vitro using a human immunodeficiency virus (HIV)-type 1-derived vector. Using enhanced green fluorescent protein (eGFP) gene as a marker placed under the phosphoglycerate kinase (PGK) promoter, gonadotroph and somatotroph adenomas were transduced even with moderate viral loads. The expression started at day 2, reached a peak at day 5, and it was still present at day 90. For targeting somatotroph and gonadotroph adenomas, human growth hormone (GH) promoter (GH -481, +54 bp) and two fragments of the human glycoprotein hormone alpha-subunit promoter (alpha-subunit 1 -520, +33 bp, and alpha-subunit 2 -907, +33 bp) were tested. In gonadotroph adenomas, the percentage of identified fluorescent cells and the fluorescence intensity analyzed by fluorescence-activated cell sorting indicated that the strength of the alpha-subunit 1 and alpha-subunit 2 promoters were comparable to that of the PGK promoter. Primary cultures of rat pituitary cells showed that alpha-subunit 1 is more selective to thyreotroph and gonadotroph phenotypes than alpha-subunit 2. GH promoter activity appeared weak in somatotroph adenomas. The human GH enhancer did not increase the GH promoter activity at all but the human prolactin promoter (-250 bp) allowed 4-fold more fluorescent cells to be obtained than the GH promoter. Several cell lines appeared too permissive to test cell-specificity of pituitary promoters. However, on human non-pituitary cell cultures, the tested pituitary promoters seemed clearly selective to target endocrine pituitary phenotypes. This study gives a starting point for a gene-therapy program using lentiviral vectors to transfer therapeutic genes in human pituitary adenomas.

Benign intracranial hypertension and thyreostimulin suppression hormonotherapy.

PURPOSE: To report a case of benign intracranial hypertension occurring during thyreostimulin suppression hormonotherapy after thyroidectomy for papillary cancer. DESIGN: Interventional case report. METHODS: A 45-year-old woman underwent total thyroidectomy for a 7-mm papillary cancer. Seventeen years later, she experienced headache, dizziness, irritability, sensation of full head, and blurred vision of the right eye while being treated with a mix of L thyroxin (LT4) and liothyronin (LT3). Ophthalmological data (including the presence of papilledema), cerebroorbital magnetic resonance imaging, and lumbar pressure evaluation confirmed benign intracranial hypertension. RESULTS: Substitutive hormonotherapy was decreased under specialized surveillance, permitting remission of benign intracranial hypertension symptoms and papilledema. CONCLUSIONS: Benign intracranial hypertension is usually difficult to cure, and its association with thyroid hormonotherapy is rare. In our patient, tapering LT4 and withdrawal of LT3 until a euthyroidal state was obtained resulted in successful treatment of benign intracranial hypertension.

[Pathology of myxoid bone tumors of the skull base]. / Tumeurs osseuses myxoïdes de la base du crâne: à propos de 9 cas.

Myxoid bone tumors of the skull encompass chordomas and chondrosarcomas. Their accurate diagnosis is usually a challenge and it is of utmost importance to identify chordomas because of the poorer prognosis. Even if the topography of the tumor is suggestive (median versus lateral), modern imaging is not specific enough and the diagnosis is based on histological features. We report nine cases of myxoid bone tumors of the skull including four chordomas, one chondroid chordoma and four chondrosarcomas. Smears are useful for rapid intraoperative diagnosis. Chondrosarcomas show cords of small round cells in a myxoid background while chordomas are made of multilayered sheets of larger, often vacuolated cells. Histology shows areas of cartilaginous matrix associated with myxoid areas in chondrosarcomas and in chondroid chordomas. Immunohistochemistry is determinant showing the expression of epithelial markers and Tau protein in chordomas only.

Neutralization of adrenomedullin inhibits the growth of human glioblastoma cell lines in vitro and suppresses tumor xenograft growth in vivo.

Presently, there is no effective treatment for glioblastoma, the most malignant and common brain tumor. Growth factors are potential targets for therapeutic strategies because they are essential for tumor growth and progression. Peptidylglycine alpha-amidating monooxygenase is the enzyme producing alpha-amidated bioactive peptides from their inactive glycine-extended precursors. The high expression of peptidylglycine alpha-amidating monooxygenase mRNA in glioblastoma and glioma cell lines points to the involvement of alpha-amidated peptides in tumorigenic growth processes in the brain. After screening of amidated peptides, it was found that human glioblastoma cell lines express high levels of adrenomedullin (AM) mRNA, and that immunoreactive AM is released into the culture medium. AM is a multifunctional regulatory peptide with mitogenic and angiogenic capabilities among others. Real-time quantitative reverse transcriptase-polymerase chain reaction analysis showed that AM mRNA was correlated to the tumor type and grade, with high expression in all glioblastomas analyzed, whereas a low expression was found in anaplastic astrocytomas and barely detectable levels in low-grade astrocytomas and oligodendrogliomas. In the present study we also demonstrate the presence of mRNA encoding the putative AM receptors, calcitonin receptor-like receptor/receptor activity-modifying protein-2 and -3 (CRLR/RAMP2; CRLR/RAMP3) in both glioma tissues and glioblastoma cell lines and further show that exogenously added AM can stimulate the growth of these glioblastoma cells in vitro. These findings suggest that AM may function as an autocrine growth factor for glioblastoma cells. One way to test the autocrine hypothesis is to interrupt the function of the endogenously produced AM. Herein, we demonstrate that a polyclonal antibody specific to AM, blocks the binding of the hormone to its cellular receptors and decreases by 33% (P < 0.001) the growth of U87 glioblastoma cells in vitro. Intratumoral administration of the anti-AM antibody resulted in a 70% (P < 0.001) reduction in subcutaneous U87 xenograft weight 21 days after treatment. Furthermore, the density of vessels was decreased in the antibody-treated tumors. These findings support that AM may function as a potent autocrine/paracrine growth factor for human glioblastomas and demonstrate that inhibition of the action of AM (produced by tumor cells) may suppress tumor growth in vivo.

PAI-1 and EGFR expression in adult glioma tumors: toward a molecular prognostic classification.

PURPOSE: Molecular classification of gliomas is a major challenge in the effort to improve therapeutic decisions. The plasminogen activator system, including plasminogen activator inhibitor type 1 (PAI-1), plays a key role in tumor invasion and neoangiogenesis. Epidermal growth factor receptor (EGFR) is involved in the control of proliferation. The contribution of PAI-1 and EGFR to the survival of gliomas was retrospectively investigated. METHODS AND MATERIALS: Fifty-nine adult gliomas treated by neurosurgery and conventional irradiation were analyzed, including 9 low-grade (2) and 50 high-grade (3-4) tumors (WHO classification). PAI-1 was measured on cytosols and EGFR on solubilized membranes using ELISA methods. RESULTS: High PAI-1 levels were strongly associated with high histologic grade (p < 0.001) and histologic necrosis (p < 0.001). PAI-1 also correlated positively with patient age (p = 0.05) and negatively with Karnofsky index (p = 0.01). By univariate analysis of the high-grade population, higher PAI-1 (p < 0.0001) and EGFR values (p = 0.02) were associated with shorter overall survival. Only PAI-1 was an independent factor in multivariate analysis. Grade 3 tumors with low PAI-1 (100% 3-year overall survival rate) presented the same clinical outcome as the low-grade tumors. CONCLUSIONS: In this prognostic study, PAI-1 and EGFR expression revealed similarities and differences between high-grade gliomas that were not apparent by traditional clinical criteria. These data strongly support that biologic factors should be included in glioma classification and the design of clinical trials to treat more homogeneous populations.