Non-functioning pituitary adenomas

Excess mortality in patients with non-functioning pituitary adenoma: a systematic review and meta-analysis

BACKGROUND

Patients with non-functioning pituitary adenoma (NFPA) often present with a variety of clinical manifestations and comorbidities, mainly determined by the local mass effect of the tumor and by hypopituitarism. Whether this has an impact on overall mortality, however, is still unclear.

METHODS

PubMed/Medline, EMBASE, and Cochrane Library databases were systematically searched until May 2023 for studies reporting data either about standardized mortality ratios (SMRs) or about predictors of mortality in patients with NFPA. Effect sizes were pooled through a random-effect model. This systematic review and meta-analysis was registered in the International Prospective Register of Systematic Reviews (PROSPERO, #CRD42023417782).

RESULTS

Eleven studies were eligible for inclusion in the systematic review; among these, five studies reported data on SMRs, with a total follow-up time of approximately 130,000 person-years. Patients with NFPA showed an increased mortality risk compared to the general population (SMR = 1.57 [95%CI: 1.20-1.99], p < 0.01). Age and sex appeared to act as effect modifiers, with a trend towards higher SMRs in females (SMR = 1.57 [95%CI: 0.91-2.41], p = 0.10) than in males (SMR = 1.00 [95%CI: 0.89-1.11], p = 0.97), and in patients diagnosed at age 40 years or younger (SMR = 3.19 [95%CI: 2.50-3.97], p < 0.01) compared to those with later onset of the disease (SMR = 1.26 [95%CI: 0.93-1.65], p = 0.13). The trend towards excess mortality was similar in patients with normal (SMR = 1.22 [95%CI: 0.94-1.53], p = 0.13) or deficient (SMR = 1.26 [95%CI: 0.82-1.79], p = 0.27) pituitary function.

CONCLUSIONS

Excess mortality is observed in patients with NFPA, regardless of pituitary function, especially in women and in patients with a younger age at diagnosis.

Bilateral Sixth Nerve Palsy: A Rare Presentation of Primary Hypophysitis

Cranial nerve palsy is common in pituitary disease and depends on the extension of the lesion into the cavernous sinuses. Bilateral cranial nerve palsy was described in pituitary adenomas with apoplexy and in only one case in hypophysitis. We present a case of a 32-year-old female manifesting with headache, diplopia, bilateral sixth nerve palsy, and hypopituitarism. Magnetic resonance imaging (MRI) revealed symmetric expansion of the pituitary gland, with bilateral cavernous sinus invasion and thickening of the pituitary stalk. Hypophysitis was suspected, and after treatment with IV methylprednisolone boluses, a decrease in the pituitary lesion was observed, with complete remission of sixth nerve palsy in the right eye and partial improvement in the left eye. In this case, we report an infrequent form of presentation of hypophysitis, and highlight that steroids are the first line of treatment.

The Novel SSTR3 Agonist ITF2984 Exerts Antimitotic and Proapoptotic Effects in Human Non-Functioning Pituitary Neuroendocrine Tumor (NF-PitNET) Cells

Somatostatin receptor ligands (SRLs) with high affinity for somatostatin receptors 2 and 5 (SSTR2 and SSTR5) are poorly efficacious in NF-PitNETs, expressing high levels of SSTR3. ITF2984 is a pan-SSTR ligand with high affinity for SSTR3, able to induce SSTR3 activation and to exert antitumoral activity in the MENX rat model. The aim of this study was to test ITF2984's antiproliferative and proapoptotic effects in NF-PitNET primary cultured cells derived from surgically removed human tumors and to characterize their SSTR expression profile. We treated cells derived from 23 NF-PitNETs with ITF2984, and a subset of them with octreotide, pasireotide (SRLs with high affinity for SSTR2 or 5, respectively), or cabergoline (DRD2 agonist) and we measured cell proliferation and apoptosis. SSTR3, SSTR2, and SSTR5 expression in tumor tissues was analyzed by qRT-PCR and Western blot. We demonstrated that ITF2984 reduced cell proliferation (-40.8 (17.08)%, p < 0.001 vs. basal, n = 19 NF-PitNETs) and increased cell apoptosis (+41.4 (22.1)%, p < 0.001 vs. basal, n = 17 NF-PitNETs) in all tumors tested, whereas the other drugs were only effective in some tumors. In our model, SSTR3 expression levels did not correlate with ITF2984 antiproliferative nor proapoptotic effects. In conclusion, our data support a possible use of ITF2984 in the pharmacological treatment of NF-PitNET.

Incidental versus symptomatic nonfunctioning pituitary adenomas: Are they different?

BACKGROUND

Nonfunctioning pituitary adenomas (NFPAs) constitute one of the most common tumours in the sellar region and are often discovered only when associated with compressive symptoms. With the frequent use of brain imaging, there has been an increase in the prevalence of incidentally discovered NFPAs.

AIM

We aim to determine the prevalence of incidental diagnosis with NPAs observed over a decade and compare the analytical, clinical and treatment differences between those who were diagnosed either incidentally or symptomatically. We also intend to evaluate the pathology differences between both groups.

METHODS

We retrospectively analysed patients aged ≥18 years with an apparent NFPA, defined as a pituitary lesion compatible with pituitary adenoma which is not associated with the clinical or biochemical evidence of a hormone-secreting tumour. Inclusion criteria included normal prolactin level for lesions <9 mm or a prolactin level <100 ng/mL for lesions ≥10 mm in maximal tumour diameter.

RESULTS

We included 119 patients [53.8% males; mean age: 56.8 years (SD = 16.7)]. Diagnosis was incidental in 47.1% of patients, and many patients had unappreciated signs and symptoms of pituitary disease. In the symptomatic and incidental groups, 66.7% and 41.1% of patients had hypopituitarism, respectively (p = .005). Only 20.4% of patients incidentally diagnosed had microadenoma (p = .060). Hypopituitarism was present in 18.8% of those patients with microadenomas. Most tumours were macroadenomas (87.4%). Half of those patients diagnosed incidentally were submitted to surgery, compared with 75.8% of those who were diagnosed symptomatically (p = .004).

CONCLUSIONS

Nonfunctioning pituitary adenomas are commonly diagnosed incidentally, with many manifesting symptoms on examination. NFPAs incidentally diagnosed are more commonly macroadenomas and less frequently associated with hypopituitarism than symptomatic. Accordingly, if there was a greater level of knowledge and more suspicion about these pathologies, it might be possible to discover them earlier.

Early Retinal Microcirculation in Nonfunctioning Pituitary Adenomas Without Visual Field Defects Using Optical Coherence Tomography Angiography

BACKGROUND

For patients with nonfunctioning pituitary adenoma (NFPA) without manifesting visual acuity impairment or visual field defect (VFD), more sensitive and objective assessment methods will allow earlier detection before irreversible damage to the visual system. This study aimed to evaluate retinal vessel densities (VDs) alterations in these patients using optical coherence tomography angiography and to determine its diagnostic abilities.

METHODS

Between patients with NFPA without VFDs and age-matched, sex-matched healthy control individuals, comparisons of visual field metrics, retinal structural thickness, and microcirculation were conducted after adjusting for axial length (AL) and signal index of scans. Receiver operating characteristic (ROC) curves were further depicted to assess the diagnostic performance of significant parameters. To explore the impact of symptom duration, tumor size, and axial length on the significant parameters, multivariate regression analysis was conducted.

RESULTS

This cross-sectional study reviewed 107 patients with NFPA. Twenty-seven eyes of patients with NFPA without VFDs and 27 eyes of healthy controls were enrolled. Compared with healthy controls, patients with NFPA without VFDs had similar foveal avascular zone areas and perimeters, macular ganglion cell complex (mGCC) and peripapillary retinal nerve fiber layer thicknesses, and macular VDs. Only the VD in the radial peripapillary capillary (RPC) segment of the inferior temporal (IT) sector was much lower in the patient group. The 2 largest area under the ROC curves were the focal loss volume (FLV) of the mGCC and the VD in the RPC of the IT sector, both of which were significantly related to symptom duration and tumor size.

CONCLUSIONS

At the early stage of NFPA before VFD and retinal thickness thinning, fundus microcirculation impairments may occur initially in the microvascular density of the RPC segment of the IT sector. The FLV and the VD of RPC at the IT sector may provide a basis for the early diagnosis of NFPA without VFD in clinical practice.

Current medical treatment and perspective in gonadotroph tumors

Gonadotroph cell adenoma is the most common clinically nonfunctioning pituitary adenoma; and is pathologically defined by immunopositivity for SF-1, GATA2 and ER-α. Most tumors also stain for follicle stimulating hormone and luteinizing hormone β-subunits, but are usually hormonally silent and discovered incidentally or due to local mass effects. Complete transsphenoidal resection should be attempted when surgery is indicated. Post-surgical treatment can include radiation of the tumor remnant and medical treatment. Among medical treatments, dopamine agonists show the best evidence for preventing the need for recurrent surgery or radiation, and should be considered in patients with relatively bulky remnants or who have high risk features associated with tumor progression. Temozolomide is indicated for aggressive adenomas and carcinomas. Less well-established treatments include somatostatin receptor ligands, peptide receptor radionucleotide therapy and immunomodulatory agents.

The use of optical coherence tomography angiography in patients with chiasmal compression (literature review)

Optical coherence tomography (OCT) is currently the leading method for the observation and evaluation of microstructural changes in the retina in vivo. In recent years, OCT has been used in clinical practice to monitor the progression of compressive optic neuropathy in patients with chiasmal-sellar region neoplasms. The results obtained in the course of the studies opened up new opportunities for studying the pathogenesis of the development of compressive optic neuropathy in patients of this group. The advent of OCT-angiography (OCTA), developed on the basis of OCT, made it possible to study changes in the blood flow of the radial peripapillary capillary network, superficial and deep capillary plexuses, which opens up many opportunities for further research into the pathogenesis of visual impairment in this group of patients, prognosis of the development of the disease, and selection optimal terms of treatment. The literature review presents and analyzes the currently available results of the use of OCTA in patients with chiasmal compression.

Deep Learning for Prediction of Progression and Recurrence in Nonfunctioning Pituitary Macroadenomas: Combination of Clinical and MRI Features

Objectives

A subset of non-functioning pituitary macroadenomas (NFMAs) may exhibit early progression/recurrence (P/R) after tumor resection. The purpose of this study was to apply deep learning (DL) algorithms for prediction of P/R in NFMAs.

Methods

From June 2009 to December 2019, 78 patients diagnosed with pathologically confirmed NFMAs, and who had undergone complete preoperative MRI and postoperative MRI follow-up for more than one year, were included. DL classifiers including multi-layer perceptron (MLP) and convolutional neural network (CNN) were used to build predictive models. Categorical and continuous clinical data were fed into the MLP model, and images of preoperative MRI (T2WI and contrast enhanced T1WI) were analyzed by the CNN model. MLP, CNN and multimodal CNN-MLP architectures were performed to predict P/R in NFMAs.

Results

Forty-two (42/78, 53.8%) patients exhibited P/R after surgery. The median follow-up time was 42 months, and the median time to P/R was 25 months. As compared with CNN using MRI (accuracy 83%, precision 87%, and AUC 0.84) or MLP using clinical data (accuracy 73%, precision 73%, and AUC 0.73) alone, the multimodal CNN-MLP model using both clinical and MRI features showed the best performance for prediction of P/R in NFMAs, with accuracy 83%, precision 90%, and AUC 0.85.

Conclusions

DL architecture incorporating clinical and MRI features performs well to predict P/R in NFMAs. Pending more studies to support the findings, the results of this study may provide valuable information for NFMAs treatment planning.

Muti-omics integration analysis revealed molecular network alterations in human nonfunctional pituitary neuroendocrine tumors in the framework of 3P medicine

Nonfuctional pituitary neuroendocrine tumor (NF-PitNET) is highly heterogeneous and generally considered a common intracranial tumor. A series of molecules are involved in NF-PitNET pathogenesis that alter in multiple levels of genome, transcriptome, proteome, and metabolome, and those molecules mutually interact to form dynamically associated molecular-network systems. This article reviewed signaling pathway alterations in NF-PitNET based on the analyses of the genome, transcriptome, proteome, and metabolome, and emphasized signaling pathway network alterations based on the integrative omics, including calcium signaling pathway, cGMP-PKG signaling pathway, mTOR signaling pathway, PI3K/AKT signaling pathway, MAPK (mitogen-activated protein kinase) signaling pathway, oxidative stress response, mitochondrial dysfunction, and cell cycle dysregulation, and those signaling pathway networks are important for NF-PitNET formation and progression. Especially, this review article emphasized the altered signaling pathways and their key molecules related to NF-PitNET invasiveness and aggressiveness that are challenging clinical problems. Furthermore, the currently used medication and potential therapeutic agents that target these important signaling pathway networks are also summarized. These signaling pathway network changes offer important resources for insights into molecular mechanisms, discovery of effective biomarkers, and therapeutic targets for patient stratification, predictive diagnosis, prognostic assessment, and targeted therapy of NF-PitNET.

Retinal Microvascular Alterations Detected by Optical Coherence Tomography Angiography in Nonfunctioning Pituitary Adenomas

Purpose

Visual impairment assessment plays a significant role in diagnosis and clinical decisions in nonfunctioning pituitary adenoma (NFPA). Retinal microvascular alterations may potentially reflect the visual impairment. The purpose of this study was to evaluate fundus microvascular alterations in patients with NFPA.

Methods

Comparisons of visual field, retinal structure, and microcirculation were conducted between patients with NFPA and age- and sex-matched healthy controls. Multivariate regression modeling was used to assess the relationship between symptom duration, sellar mass size, and fundus vessel density (VD) of patients. Receiver operating characteristic (ROC) curves were depicted to determine the diagnostic performance of significant parameters to discriminate eyes with NFPA from healthy eyes.

Results

Forty eyes of patients and 40 eyes of healthy individuals were enrolled. Compared to healthy controls, patients with NFPA had a larger foveal avascular zone area and thinner ganglion cell complex thickness. The VDs of patients presented an obvious decrease in radial peripapillary capillary (RPC) and an increase in the deep capillary plexus segment of the perifoveal area. The peripapillary VDs of patients were significantly related to sellar mass size. The area under the ROC curve of VD in the RPC segment of the temporo-inferior sector was the largest (0.801; 95% confidence interval, 0.70–0.90; P < 0.001).

Conclusions

The fundus of patients with NFPA demonstrated significant and characteristic microvascular impairments. The VDs were also significantly associated with sellar mass size.

Translational Relevance

Retinal microvascular alterations detected by optical coherence tomography angiography are characteristic and related to sellar mass size, which may provide information that facilitates the diagnosis of NFPA.

Quantitative Magnetic Resonance-Derived Biomarkers as Predictors of Function and Histotype in Adenohypophyseal Tumours

INTRODUCTION

Magnetic resonance imaging (MRI) is the main modality to diagnose adenohypophyseal tumours, while biochemical assessment of pituitary hormones allows for their functional classification. In this retrospective exploratory cohort study, we investigated if quantitative differences in tumour MR signal intensity (SI) could be utilized to predict the function and histotype.

METHODS

Clinically acquired pretreatment MRI images were retrospectively analysed in 67 clinically non-functioning gonadotropinomas (NFG), 38 somatotropinomas, and 16 medically treated giant macroprolactinomas. Mean T1- and T2-weighted SI values were determined for each tumour and normalized against either centrum semiovale white matter or CSF to derive relative T1W and T2W SI values and the relative tumour T2/T1 SI ratio. Inter-group differences in quantitative MR parameters were compared, and the power of each parameter to discriminate tumour type and subtype was assessed using the area under the receiver operator characteristic curve (AUROC). In resected somatotropinomas, the relationship between tumour granulation status, relative MR SI values, and biochemical data was also compared.

RESULTS

Compared to somatotropinomas, NFG and macroprolactinomas displayed higher relative T2W SI (p < 0.001) and higher relative tumour T2/T1 SI ratio values (p < 0.001, ANOVA). Compared to intermediate/densely granulated tumours, sparsely granulated somatotropinomas were larger (p = 0.006, Mann-Whitney U test), had higher relative T2W SI (p ≤ 0.005), and higher relative tumour T2/T1 SI ratios (p ≤ 0.001, 2-tailed t test). Relative tumour T2W SI values and relative tumour T2/T1 ratio values demonstrated good discriminatory power in differentiating NFG from somatotropinoma (AUROC = 0.87-0.94) and predicting somatotropinoma subtypes (AUROC = 0.87-0.95).

CONCLUSION

Quantitative SI-based MR parameters derived using clinical acquisition MRI protocols may help non-invasively discriminate the functional status of adenohypophyseal tumours and the histological subtype of somatotropinomas.

Clinically non-functioning pituitary adenomas

Clinically non functioning pituitary adenomas (NFPAs) include all pituitary adenomas that are not hormonally active. They are not associated with clinical syndromes such as amenorrhea-galactorrhea (prolactinomas), acromegaly, Cushing's disease or hyperthyroidism (TSH-secreting adenomas) and are therefore usually diagnosed by signs and symptoms related to a mass effect (headache, visual impairment, sometimes pituitary apoplexy), but also incidentally. Biochemical work up often documents several pituitary insufficiencies. In histopathology, the majority of NFPAs are gonadotroph. In the absence of an established medical therapy, surgery is the mainstay of treatment, unless contraindicated or in particular situations (e.g. small incidentalomas, distance from optic pathways). Resection, generally via a trans-sphenoidal approach (with the help of an endoscope), should be performed by a neurosurgeon with extensive experience in pituitary surgery, in order to maximize the chances of complete resection and to minimize complications. If a tumor remnant persists, watchful waiting is preferred to routine radiotherapy, as long as the tumor residue does not grow and is distant from the optic pathways. NFPA can sometimes recur even after complete resection, but predicting the individual risk of tumor remnant progression is difficult. Postoperative irradiation is only considered in case of residual tumor growth or relapse, due to its potential side effects.

TGF-β1/Smad2/3 signaling pathway modulates octreotide antisecretory and antiproliferative effects in pituitary somatotroph tumor cells

Octreotide (OCT) is used to inhibit hormone secretion and growth in somatotroph tumors, although a significant percentage of patients are resistant. It has also been tested in nonfunctioning (NF) tumors but with poor results, with these outcomes having been associated with SSTR2 levels and impaired signaling. We investigated whether OCT inhibitory effects can be improved by TGF-β1 in functioning and nonfunctioning somatotroph tumor cells. OCT effects on hormone secretion and proliferation were analyzed in the presence of TGF-β1 in WT and SSTR2-overexpressing secreting GH3 and silent somatotroph tumor cells. The mechanism underlying these effects was assessed by studying SSTR and TGFβR signaling pathways mediators. In addition, we analyzed the effects of OCT/TGF-β1 treatment on tumor growth and cell proliferation in vivo. The inhibitory effects of OCT on GH- and PRL-secretion and proliferation were improved in the presence of TGF-β1, as well as by SSTR2 overexpression. The OCT/TGF-β1 treatment induced downregulation of pERK1/2 and pAkt, upregulation of pSmad3, and inhibition of cyclin D1. In vivo experiments showed that OCT in the presence of TGF-β1 blocked tumor volume growth, decreased cell proliferation, and increased tumor necrosis. These results indicate that SSTR2 levels and the stimulation of TGF-β1/TGFβR/Smad2/3 pathway are important for strengthening the antiproliferative and antisecretory effects of OCT.

Outcome of pituitary hormone deficits after surgical treatment of nonfunctioning pituitary macroadenomas

OBJECTIVES

Nonfunctionning pituitary macroadenomas (NFPMA) are benign tumors that cause symptoms of mass effects including hypopituitarism. Their primary treatment is transsphenoidal surgery. We aimed to determine the outcome of pituitary hormone deficits after surgical treatment of NFPMA and to identify factors predicting hormonal recovery.

DESIGN

We retrospectively included 246 patients with NFPMA diagnosed and operated in one of the two participating centers. All hormonal axes were evaluated except growth hormone (GH). Postoperative improvement of pituitary endocrine function was considered if at least one hormonal deficit had recovered and a lower total number of deficits was observed 1 year after surgery.

RESULTS

80% (n = 197) of patients had one or more pituitary deficits and 28% had complete anterior hypopituitarism. Besides GH, the gonadotropic and thyrotropic axes were the most commonly affected (68% and 62%, respectively). The number of hypopituitary patients dropped significantly to 61% at 1 year (p < 0.001) and a significant improvement was observed for all hormonal axes, except central diabetes insipidus. Among patients with preoperative hypopituitarism, 88/175 (50%) showed improved pituitary function at 1 year. Both hyperprolactinemia at diagnosis and a lower tumor diameter independently predicted favorable endocrine outcome.

CONCLUSIONS

Hypopituitarism is present in 80% of patients with NFPMA and nearly half of them will benefit from sustained improvement after surgery. Hyperprolactinaemia at diagnosis and lower tumor dimensions are associated with favorable endocrine prognosis. This supports the option of early surgery in NFPMA patients with pituitary deficits independent of the presence of visual disturbances.

A Comprehensive Study of Spindle Cell Oncocytoma of the Pituitary Gland: Series of 6 Cases and Meta-Analysis of 85 Cases

OBJECTIVE

To discuss optimal treatment strategy for spindle cell oncocytoma (SCO) of the pituitary gland.

METHODS

Institutional cases were retrospectively reviewed. A systematic literature search and subsequent quantitative synthesis were performed for further analysis. The detailed features were summarized and the tumor control rate (TCR) was calculated.

RESULTS

Eighty-five patients (6 institutional and 79 literature) were included. The annual incidence was approximately 0.01-0.03/100,000. The mean age was 56 years. Vision loss was present in 60%. Seventy-three percent showed hormonal abnormalities. On magnetic resonance imaging, tumor was avidly enhancing, and the normal gland was commonly displaced anterosuperiorly. Evidence of hypervascularity was seen in 77%. Gross total resection (GTR) was achieved in only 24% because of its hypervascular, fibrous, and adhesive nature. The mean postoperative follow-up was 3.3 years for institutional cases and 2.3 years for the integrated cohort. The TCR was significantly better after GTR (5-year TCR, 75%; P = 0.012) and marginally better after non-GTR + upfront radiotherapy (5-year TCR, 76%; P = 0.103) than after non-GTR alone (5-year TCR, 24%). The TCRs for those with low Ki-67 index (≤5%) were marginally better than those with higher Ki-67 index (5-year rate, 57% vs. 23%; P = 0.110).

CONCLUSIONS

Frequent endocrine-related symptoms, hypervascular signs, and anterosuperior displacement of the gland support preoperative diagnosis of SCO. GTR seems to have better long-term tumor control, whereas the fibrous, hypervascular, and adhesive nature of SCO makes it difficult to achieve GTR. In patients with non-GTR, radiotherapy may help decrease tumor progression.

Invasive and Noninvasive Nonfunctioning Gonadotroph Pituitary Tumors Differ in DNA Methylation Level of LINE-1 Repetitive Elements

PURPOSE

Epigenetic dysregulation plays a role in pituitary tumor pathogenesis. Some differences in DNA methylation were observed between invasive and noninvasive nonfunctioning gonadotroph tumors. This study sought to determine the role of DNA methylation changes in repetitive LINE-1 elements in nonfunctioning gonadotroph pituitary tumors.

METHODS

We investigated LINE-1 methylation levels in 80 tumors and normal pituitary glands with bisulfite-pyrosequencing. Expression of two LINE-1 open reading frames (L1-ORF1 and L1-ORF2) was analyzed with qRT-PCR in tumor samples and mouse gonadotroph pituitary cells treated with DNA methyltransferase inhibitor. Immunohistochemical staining against L1-ORF1p was also performed in normal pituitary glands and tumors.

RESULTS

Hypomethylation of LINE-1 was observed in pituitary tumors. Tumors characterized by invasive growth revealed lower LINE-1 methylation level than noninvasive ones. LINE-1 methylation correlated with overall DNA methylation assessed with HM450K arrays and negatively correlated with L1-ORF1 and L1-ORF2 expression. Treatment of αT3-1 gonadotroph cells with 5-Azacytidine clearly increased the level of L1-ORF1 and L1-ORF2 mRNA; however, its effect on LβT2 cells was less pronounced. Immunoreactivity against L1-ORF1p was higher in tumors than normal tissue. No difference in L1-ORF1p expression was observed in invasive and noninvasive tumors.

CONCLUSION

Hypomethylation of LINE-1 is related to invasive growth and influences transcriptional activity of transposable elements.

Radiomics Approach for Prediction of Recurrence in Non-Functioning Pituitary Macroadenomas

Objectives

A subset of non-functioning pituitary macroadenomas (NFPAs) may exhibit early progression/recurrence (P/R) after surgical resection. The purpose of this study was to apply radiomics in predicting P/R in NFPAs.

Methods

Only patients who had undergone preoperative MRI and postoperative MRI follow-ups for more than 1 year were included in this study. From September 2010 to December 2017, 50 eligible patients diagnosed with pathologically confirmed NFPAs were identified. Preoperative coronal T2WI and contrast-enhanced (CE) T1WI imaging were analyzed by computer algorithms. For each imaging sequence, 32 first-order features and 75 texture features were extracted. Support vector machine (SVM) classifier was utilized to evaluate the importance of extracted parameters, and the most significant three parameters were used to build the prediction model. The SVM score was calculated based on the three selected features.

Results

Twenty-eight patients exhibited P/R (28/50, 56%) after surgery. The median follow-up time was 38 months, and the median time to P/R was 20 months. Visual disturbance, hypopituitarism, extrasellar extension, compression of the third ventricle, large tumor height and volume, failed optic chiasmatic decompression, and high SVM score were more frequently encountered in the P/R group (p < 0.05). In multivariate Cox hazards analysis, symptoms of sex hormones, hypopituitarism, and SVM score were high risk factors for P/R (p < 0.05) with hazard ratios of 10.71, 2.68, and 6.88. The three selected radiomics features were T1 surface-to-volume radio, T1 GLCM-informational measure of correlation, and T2 NGTDM-coarseness. The radiomics predictive model shows 25 true positive, 16 true negative, 6 false positive, and 3 false negative cases, with an accuracy of 82% and AUC of 0.78 in differentiating P/R from non-P/R NFPAs. For SVM score, optimal cut-off value of 0.537 and AUC of 0.87 were obtained for differentiation of P/R. Higher SVM scores were associated with shorter progression-free survival (p < 0.001).

Conclusions

Our preliminary results showed that objective and quantitative MR radiomic features can be extracted from NFPAs. Pending more studies and evidence to support the findings, radiomics analysis of preoperative MRI may have the potential to offer valuable information in treatment planning for NFPAs.

Cyclin A in nonfunctioning pituitary adenomas

PURPOSE

Assess cyclin A in nonfunctioning pituitary adenomas (NFPA) and compare its expression in non-invasive and non-proliferative tumors with invasive and proliferative tumors (12× higher risk of recurrence).

METHODS

Quantitative real time polymerase chain reaction to analyze cyclin A using normal pituitary gland as reference. Fold change (FC) > 1 was considered as increased. Tumor invasion was based on Knosp criteria (grades 3-4 considered invasive) and proliferation on the presence of at least two of three criteria: Ki-67 ≥ 3%; mitoses > 2/10; positive p53. Both groups were compared with Mann-Whitney test considering p value < 0.05 as statistically significant.

RESULTS

Thirty-one patients with NFPA were included. Tumors were mainly of gonadotrophic origin (74.2%), followed by corticotrophic (19.4%) and lactotrophic (3.2%) origins and null-cell adenomas (3.2%). Median tumor diameter was 3.5 cm (1.8-8.0) and Ki-67 was 3.0% (0.3-11%). Sixteen patients had tumors classified as non-invasive and non-proliferative and 15 as invasive and proliferative. Median FC was 0.31 in all tumors (0.13-1.94). Cyclin A was not related to invasion or proliferation (FC 0.41 in non-invasive and non-proliferative tumors and FC 0.30 in invasive and proliferative tumors; p = 0.968). Four (12.9%) patients had tumors that exhibited increased cyclin A [median FC of 1.04 (1.02-1.94)]-three of gonadotrophic origin and one null-cell adenoma, with two tumors classified as non-invasive and non-proliferative and two tumors classified as invasive and proliferative. Median tumor diameter in these samples was 3.4 cm (2.4-3.6) and Ki-67 was 5.1% (2-11%).

CONCLUSIONS

Cyclin A was increased in a minority of NFPA and does not seem to be related to invasion or proliferation.

Contemporary Management of Clinically Non-functioning Pituitary Adenomas: A Clinical Review

Non-functioning pituitary adenomas (NFPAs) are benign pituitary tumours that constitute about one-third of all pituitary adenomas. They typically present with symptoms of mass effects resulting in hypopituitarism, visual symptoms, or headache. Most NFPAs are macroadenomas (>1 cm in diameter) at diagnosis that can occasionally grow quite large and invade the cavernous sinus causing acute nerve compression and some patients may develop acute haemorrhage due to pituitary apoplexy. The progression from benign to malignant pituitary tumours is not fully understood; however, genetic and epigenetic abnormalities may be involved. Non-functioning pituitary carcinoma is extremely rare accounting for only 0.1% to 0.5 % of all pituitary tumours and presents with cerebrospinal, meningeal, or distant metastasis along with the absence of features of hormonal hypersecretion. Pituitary surgery through trans-sphenoidal approach has been the treatment of choice for symptomatic NFPAs; however, total resection of large macroadenomas is not always possible. Recurrence of tumours is frequent and occurs in 51.5% during 10 years of follow-up and negatively affects the overall prognosis. Adjuvant radiotherapy can decrease and prevent tumour growth but at the cost of significant side effects. The presence of somatostatin receptor types 2 and 3 (SSTR3 and SSTR2) and D2-specific dopaminergic receptors (D2R) within NFPAs has opened a new perspective of medical treatment for such tumours. The effect of dopamine agonist from pooled results on patients with NFPAs has emerged as a very promising treatment modality as it has resulted in reduction of tumour size in 30% of patients and stabilization of the disease in about 58%. Despite the lack of long-term studies on the mortality, the available limited evidence indicates that patients with NFPA have higher standardized mortality ratios (SMR) than the general population, with women particularly having higher SMR than men. Older age at diagnosis and higher doses of glucocorticoid replacement therapy are the only known predictors for increased mortality.

Suprasellar extension independently predicts preoperative pituitary hormone deficiencies in patients with nonfunctioning pituitary macroadenomas: a single-center experience

PURPOSE

Nonfunctioning pituitary adenomas (NFPAs) are among the commonest benign tumors of the pituitary. Hypopituitarism is frequently present at the time of diagnosis, and this has been attributed to stalk portal vessel compression and/or destruction of normal anterior pituitary cells. The aim of our study was to examine possible factors at diagnosis associated with the presence of hypopituitarism.

METHODS

We retrospectively evaluated the records of patients with nonfunctioning pituitary macroadenomas from the database of our department. The inclusion criterion was the availability of imaging data regarding the extension of the lesion.

RESULTS

A total of 148 patients (89 men, 60.1%) with nonfunctioning macroadenomas and available imaging data were identified. Mean age at diagnosis was 56.0 ± 14.5 years, and hypopituitarism was found in 66.2%. The maximum diameter of the adenoma, the patient's age at diagnosis, and compression of the optic chiasm were significant factors predicting the presence of hypopituitarism (OR 1.077, p = 0.006; OR 1.025, p = 0.045; and OR 2.893, p = 0.042, respectively). Suprasellar adenomas with extension to adjacent sinuses, although larger than those with only suprasellar extension, did not differ as to the degree of hypopituitarism. Moreover, in suprasellar adenomas, prolactin levels, albeit not independently, were also related to hypopituitarism (OR 1.035, p = 0.045).

CONCLUSIONS

In patients with NFPAs, prognostic factors related to increased risk of hypopituitarism are age at diagnosis, size of the adenoma, and most importantly the presence of suprasellar extension. These data accentuate the necessity for surgical decompression in case of suprasellar extension, in order, apart from saving visual acuity, to possibly avoid or reverse hypopituitarism.

DNA Methylation Influences miRNA Expression in Gonadotroph Pituitary Tumors

microRNAs are involved in pathogenesis of cancer. DNA methylation plays a role in transcription of miRNA-encoding genes and may contribute to changed miRNA expression in tumors. This issue was not investigated in pituitary neuroendocrine tumors (PitNETs) previously. DNA methylation patterns, assessed with HumanMethylation450K arrays in 34 PitNETs and five normal pituitaries, were used to determine differentially methylated CpGs located at miRNA genes. It showed aberrant methylation in regions encoding for 131 miRNAs. DNA methylation data and matched miRNA expression profiles, determined with next-generation sequencing (NGS) of small RNAs, were correlated in 15 PitNETs. This showed relationship between methylation and expression levels for 12 miRNAs. DNA methylation and expression levels of three of them (MIR145, MIR21, and MIR184) were determined in the independent group of 80 tumors with pyrosequencing and qRT-PCR and results confirmed both aberrant methylation in PitNETs and correlation between methylation and expression. Additionally, in silico target prediction was combined with analysis of established miRNA profiles and matched mRNA expression pattern, assessed with amplicon-based NGS to indicate putative target genes of epigenetically deregulated miRNAs. This study reveals aberrant DNA methylation in miRNA-encoding genes in gonadotroph PitNETs. Methylation changes affect expression level of miRNAs that regulate putative target genes with tumorigenesis-relevant functions.

Presenting Features in 269 Patients With Clinically Nonfunctioning Pituitary Adenomas Enrolled in a Prospective Study

Context

Clinically nonfunctioning pituitary adenomas (CNFPAs) typically remain undetected until mass effect symptoms develop. However, currently, head imaging is performed commonly for many other indications, which may increase incidental discovery of CNFPAs. Since current presentation and outcome data are based on older, retrospective series, a prospective characterization of a contemporary CNFPA cohort was needed.

Objective

To determine the prevalence of incidental presentation and hypopituitarism and its predictors in a CNFPA cohort that spanned 6 to 9 mm micro- to macroadenoma included observational and surgical therapy.

Methods

At enrollment in a prospective, observational study, 269 patients with CNFPAs were studied by history, examination, blood sampling, and pituitary imaging analysis and categorized into incidental or symptoms presentation groups that were compared.

Results

Presentation was incidental in 48.7% of patients and due to tumor symptoms in 51.3%. In the symptoms and incidental groups, 58.7% and 27.4% of patients had hypopituitarism, respectively, and 25% of patients with microadenomas had hypopituitarism. Many had unappreciated signs and symptoms of pituitary disease. Most tumors were macroadenomas (87%) and were larger in the symptoms than incidental and hypopituitary groups than in the eupituitary groups. The patients in the incidental group were older, and males were older and had larger tumors in both the incidental and symptoms groups.

Conclusions

Patients with CNFPAs commonly present incidentally and with previously unrecognized hypopituitarism and symptoms that could have prompted earlier diagnosis. Our data support screening all large micro and macro-CNFPAs for hypopituitarism. Most patients with CNFPAs still have mass effect signs at presentation, suggesting the need for more awareness of pituitary disease. Our ongoing, prospective observation of this cohort will assess outcomes of these CNFPA groups.

A Somatostatin Receptor Subtype-3 (SST3) Peptide Agonist Shows Antitumor Effects in Experimental Models of Nonfunctioning Pituitary Tumors

PURPOSE

Somatostatin analogues (SSA) are efficacious and safe treatments for a variety of neuroendocrine tumors, especially pituitary neuroendocrine tumors (PitNET). Their therapeutic effects are mainly mediated by somatostatin receptors SST₂ and SST₅. Most SSAs, such as octreotide/lanreotide/pasireotide, are either nonselective or activate mainly SST₂. However, nonfunctioning pituitary tumors (NFPTs), the most common PitNET type, mainly express SST₃ and finding peptides that activate this particular somatostatin receptor has been very challenging. Therefore, the main objective of this study was to identify SST₃-agonists and characterize their effects on experimental NFPT models.

EXPERIMENTAL DESIGN

Binding to SSTs and cAMP level determinations were used to screen a peptide library and identify SST₃-agonists. Key functional parameters (cell viability/caspase activity/chromogranin-A secretion/mRNA expression/intracellular signaling pathways) were assessed on NFPT primary cell cultures in response to SST₃-agonists. Tumor growth was assessed in a preclinical PitNET mouse model treated with a SST₃-agonist.

RESULTS

We successfully identified the first SST₃-agonist peptides. SST₃-agonists lowered cell viability and chromogranin-A secretion, increased apoptosis in vitro, and reduced tumor growth in a preclinical PitNET model. As expected, inhibition of cell viability in response to SST₃-agonists defined two NFPT populations: responsive and unresponsive, wherein responsive NFPTs expressed more SST₃ than unresponsive NFPTs and exhibited a profound reduction of MAPK, PI3K-AKT/mTOR, and JAK/STAT signaling pathways upon SST₃-agonist treatments. Concurrently, SSTR3 silencing increased cell viability in a subset of NFPTs.

CONCLUSIONS

This study demonstrates that SST₃-agonists activate signaling mechanisms that reduce NFPT cell viability and inhibit pituitary tumor growth in experimental models that expresses SST₃, suggesting that targeting this receptor could be an efficacious treatment for NFPTs.

Visual Outcomes after Endoscopic Endonasal Transsphenoidal Resection of Pituitary Adenomas: Our Institutional Experience

Objectives  Visual dysfunction in patients with pituitary adenomas is a clear indication for endoscopic endonasal transsphenoidal surgery (EETS). However, the visual outcomes vary greatly among patients and it remains unclear what tumor, patient, and surgical characteristics contribute to postoperative visual outcomes. Methods  One hundred patients with pituitary adenomas who underwent EETS between January 2011 and June 2015 in a single institution were retrospectively reviewed. General patient characteristics, pre- and postoperative visual status, clinical presentation, tumor characteristics, hormone production, radiological features, and procedural characteristics were evaluated for association with presenting visual signs and visual outcomes postoperatively. Suprasellar tumor extension (SSE) was graded 0 to 4 following a grading system as formulated by Fujimoto et al. Results  Sixty-six (66/100) of all patients showed visual field defects (VFD) at the time of surgery, of whom 18% (12/66) were asymptomatic. VFD improved in 35 (35%) patients and worsened in 4 (4%) patients postoperatively. Mean visual acuity (VA) improved from 0.67 preoperatively to 0.84 postoperatively ( p  = 0.04). Nonfunctioning pituitary adenomas (NFPAs) and Fujimoto grade were independent predictors of preoperative VFD in the entire cohort ( p  = 0.02 and p  < 0.01 respectively). A higher grade of SSE was the only factor independently associated with postoperative improvement of VFD ( p  = 0.03). NFPA and Fujimoto grade 3 were independent predictors of VA improvement (both p  = 0.04). Conclusion  EETS significantly improved both VA and VFD for most patients, although a few patients showed deterioration of visual deficits postoperatively. Higher degrees of SSE and NFPA were independent predictors of favorable visual outcomes.

Prediction of recurrence in solid nonfunctioning pituitary macroadenomas: additional benefits of diffusion-weighted MR imaging

OBJECTIVE

A subset of benign, nonfunctioning pituitary macroadenomas (NFMAs) has been shown to undergo early progression/recurrence (P/R) during the first years after surgical resection. The aim of this study was to determine preoperative MR imaging features for the prediction of P/R in benign solid NFMAs, with emphasis on apparent diffusion coefficient (ADC) values.

METHODS

We retrospectively investigated the preoperative MR imaging features for the prediction of P/R in benign solid NFMAs. Only the patients who had undergone preoperative MRI and postoperative MRI follow-ups for more than 1 year (at least every 6-12 months) were included. From November 2010 to December 2016, a total of 30 patients diagnosed with benign solid NFMAs were included (median follow-up time 45 months), and 19 (63.3%) patients had P/R (median time to P/R 24 months).

RESULTS

Benign solid NFMAs with cavernous sinus invasion, failed chiasmatic decompression, large tumor height and tumor volume, high diffusion-weighted imaging (DWI) signal, and lower ADC values/ratios were significantly associated with P/R (p < 0.05). The cutoff points of ADC value and ADC ratio for prediction of P/R are 0.77 × 10-3 mm2/sec and 1.01, respectively, with area under the curve (AUC) values (0.9 and 0.91) (p < 0.01). In multivariate Cox proportional hazards analysis, low ADC value (< 0.77 × 10-3 mm2/sec) is a high-risk factor of P/R (p < 0.05) with a hazard ratio of 14.07.

CONCLUSIONS

Benign solid NFMAs with low ADC values/ratios are at a significantly increased risk of P/R, and aggressive treatments accompanied by close follow-up with imaging studies should be considered.

SDF-1α/MicroRNA-134 Axis Regulates Nonfunctioning Pituitary Neuroendocrine Tumor Growth via Targeting VEGFA

BACKGROUND

Nonfunctioning pituitary neuroendocrine tumor (NF-PitNET) is difficult to resect. Except for surgery, there is no effective treatment for NF-PitNET. MicroRNA-134 (miR-134) has been reported to inhibit proliferation and invasion ability of tumor cells. Herein, the mechanism underlying the effect of miR-134 on alleviating NF-PitNET tumor cells growth is explored.

METHODS

Mouse pituitary αT3-1 cells were transfected with miR-134 mimics and inhibitor, followed by treatment with stromal cell-derived factor-1α (SDF-1α) in vitro. MiR-134 expression level: we used quantitative real-time PCR (qRT-PCR) to detect the expression of miR-134. Cell behavior level: cell viability and invasion ability were assessed using a cell counting kit-8 (CCK8) assay and Transwell invasion assay respectively. Cytomolecular level: tumor cell proliferation was evaluated by Ki-67 staining; propidium iodide (PI) staining analyzed the effect of miR-134 on cell cycle arrest; western blot analysis and immunofluorescence staining evaluated tumor migration and invasive ability. Additionally, we collected 27 NF-PitNET tumor specimens and related clinical data. The specimens were subjected to qRT-PCR to obtain the relative miR-134 expression level of each specimen; linear regression analysis was used to analyze the miR-134 expression level in tumor specimens and the age of the NF-PitNET population, gender, tumor invasion, prognosis, and other indicators.

RESULTS

In vitro experiment, miR-134 was observed to significantly inhibit αT3-1 cells proliferation characterized by inhibited cell viability and expressions of vascular endothelial growth factor A (VEGFA) and cell cycle transition from G1 to S phase (P < 0.01). VEGFA was verified as a target of miR-134. Additionally, miR-134-induced inhibition of αT3-1 cell proliferation and invasion was attenuated by SDF-1α and VEGFA overexpression (P < 0.01). In primary NF-PitNET tumor analysis, miR-134 expression level was negatively correlated with tumor invasion (P = 0.003).

CONCLUSION

The regulation of the SDF-1α/miR-134/VEGFA axis represents a novel mechanism in the pathogenesis of NF-PitNETs and may serve as a potential therapeutic target for the treatment of NF-PitNETs.

The Role of Aberrant DNA Methylation in Misregulation of Gene Expression in Gonadotroph Nonfunctioning Pituitary Tumors

Gonadotroph nonfunctioning pituitary adenomas (NFPAs) are common intracranial tumors, but the role of aberrant epigenetic regulation in their development remains poorly understood. In this study, we investigated the effect of impaired CpG methylation in NFPAs. We determined DNA methylation and transcriptomic profiles in 32 NFPAs and normal pituitary sections using methylation arrays and sequencing, respectively. Ten percent of differentially methylated CpGs were correlated with gene expression, and the affected genes are involved in a variety of tumorigenesis-related pathways. Different proportions of gene body and promoter region localization were observed in CpGs with negative and positive correlations between methylation and gene expression, and different proportions of CpGs were located in 'open sea' and 'shelf/shore' regions. The expression of ~8% of genes differentially expressed in NFPAs was related to aberrant methylation. Methylation levels of seven CpGs located in the regulatory regions of FAM163A, HIF3A and PRSS8 were determined by pyrosequencing, and gene expression was measured by qRT-PCR and immunohistochemistry in 83 independent NFPAs. The results clearly confirmed the negative correlation between methylation and gene expression for these genes. By identifying which aberrantly methylated CpGs affect gene expression in gonadotrophinomas, our data confirm the role of aberrant methylation in pathogenesis of gonadotroph NFPAs.

Clinical, pathologic, and imaging characteristics of pituitary null cell adenomas as defined according to the 2017 World Health Organization criteria: a case series from two pituitary centers

PURPOSE

The 2017 World Health Organization classification of pituitary tumors redefined pituitary null cell adenomas (NCAs) by restricting this diagnostic category to pituitary tumors that are negative for pituitary transcription factors and adenohypophyseal hormones. The clinical behavior of this redefined entity has not been widely studied, and this is a major shortcoming of the classification. This study evaluated the imaging and clinical features of NCAs from two pituitary centers and compared them with those of gonadotroph adenomas (GAs).

METHODS

Imaging, pathologic, and clinical characteristics of NCAs and GAs were retrospectively reviewed. Tumor immunohistochemistry was performed to confirm absence of adenohypophyseal hormones and pituitary transcription factor expression.

RESULTS

Thirty-one NCAs were compared with 38 GAs. NCAs were more likely to invade the cavernous sinus (15/31 [48%] vs. 5/38 [13%], P = .003) and had a higher proliferative index (i.e., MIB-1 > 3%, 11/31 [35%] vs. 5/38 [13%], P = .04). Gross total resection was less likely in the NCA group (19/31 [61%] vs. 33/38 [87], P = .02). Progression-free survival was worse in the NCA cohort (5-year progression-free survival, 0.70 vs. 1.00; P = .011, by log-rank test).

CONCLUSIONS

Compared with GAs, NCAs are more invasive at the time of presentation and have a more aggressive clinical course. This study provides evidence that NCAs represent a distinct clinicopathologic entity with behavior that differs adversely from that of GAs. This may inform clinical decision-making, including frequency of postoperative tumor surveillance and timing of adjunctive treatments.

Quantitative Analysis of Ubiquitinated Proteins in Human Pituitary and Pituitary Adenoma Tissues

Protein ubiquitination is an important post-translational modification that is associated with multiple diseases, including pituitary adenomas (PAs). Protein ubiquitination profiling in human pituitary and PAs remains unknown. Here, we performed the first ubiquitination analysis with an anti-ubiquitin antibody (specific to K-ε-GG)-based label-free quantitative proteomics method and bioinformatics to investigate protein ubiquitination profiling between PA and control tissues. A total of 158 ubiquitinated sites and 142 ubiquitinated peptides in 108 proteins were identified, and five ubiquitination motifs were found. KEGG pathway network analysis of 108 ubiquitinated proteins identified four statistically significant signaling pathways, including PI3K-AKT signaling pathway, hippo signaling pathway, ribosome, and nucleotide excision repair. R software Gene Ontology (GO) analysis of 108 ubiquitinated proteins revealed that protein ubiquitination was involved in multiple biological processes, cellular components, and molecule functions. The randomly selected ubiquitinated 14-3-3 zeta/delta protein was further analyzed with Western blot, and it was found that upregulated 14-3-3 zeta/delta protein in nonfunctional PAs might be derived from the significantly decreased level of its ubiquitination compared to control pituitaries, which indicated a contribution of 14-3-3 zeta/delta protein to pituitary tumorigenesis. These findings provided the first ubiquitinated proteomic profiling and ubiquitination-involved signaling pathway networks in human PAs. This study offers new scientific evidence and basic data to elucidate the biological functions of ubiquitination in PAs, insights into its novel molecular mechanisms of pituitary tumorigenesis, and discovery of novel biomarkers and therapeutic targets for effective treatment of PAs.

Growth Pattern and Prognostic Factors of Untreated Nonfunctioning Pituitary Adenomas

Objective

Pituitary adenomas (PAs) are often detected as incidental findings. However, the natural history remains unclear. The objective of this study was to evaluate the natural history and growth pattern of untreated PAs.

Methods

Between 2003 and 2014, 59 PAs were managed with clinico-radiological follow up for longer than 12 months without any kind of therapeutic intervention. Tumor volumes were calculated at initial and last follow-up visit, and tumor growth during the observation period was determined. Data were analyzed according to clinical and imaging characteristics.

Results

The mean initial and last tumor volume and diameter were 1.83±2.97 mL and 13.77±6.45 mm, 2.85±4.47 mL and 15.75±8.08 mm, respectively. The mean annual tumor growth rate was 0.33±0.68 mL/year during a mean observation period of 46.8±32.1 months. Sixteen (27%) PAs showed tumor growth. The initial tumor size (HR, 1.140; 95% confidence interval, 1.003–1.295; p=0.045) was the independent predictive factor that determined the tumor growth. Six patients (11%) of 56 conservatively managed non-symptomatic PAs underwent resection for aggravating visual symptoms with mean interval of 34.5 months from diagnosis. By Cox regression analysis, PAs of last longest diameter over 21.75 mm were a significant prognostic factor for eventual treatment.

Conclusion

The initial tumor size of PAs was independently associated with the tumor growth. Six patients (11%) of conservatively managed PAs were likely to be treated eventually. PAs of last follow-up longest diameter over 21.75 mm were a significant prognostic factor for treatment. Further studies with a large series are required to determine treatment strategy.

[Morphofunctional features of non-functioning pituitary adenomas]

Non-functioning pituitary adenomas (NFPAs) account for about 30% of all pituitary tumors. NFPAs are characterized by the lack of secretory potential or its weak expression insufficient for determination of the blood level of adenohypophyseal tropic hormones and for development of a specific clinical picture. Morphologically, NFPAs are a heterogeneous group of tumors, the classification of which was previously based only on immunoreactivity for pituitary tropic hormones. The WHO revised its Classification of Tumors of Endocrine Organs (4th edition) in 2017. The main changes relate to adenohypophysial-cell lineage for the designation of adenomas into subtypes. The introduction of transcription factor antibodies has become a fundamentally new approach to the classification of NFPAs, which is necessary to recognize less differentiated tumor types. This paper provides information on the new histopathological classification of pituitary adenomas, on the theories of silent adenomas, and on the proliferative and prognostic markers of NFPAs.

A two‑circRNA signature predicts tumour recurrence in clinical non‑functioning pituitary adenoma

Clinical non‑functioning pituitary adenoma (NFPA) accounts for >30% of all pituitary adenomas, and the recurrence rate is notably high. The ability to predict tumour recurrence during initial surgery will aid in determining if adjunctive therapy is required to reduce recurrence. With the aim of developing a circular RNA (circRNA) signature to improve prognosis prediction in NFPA, the present study examined the circRNA expression profiles in 73 patients with NFPA from Beijing Tiantan Hospital using high‑throughput RNA chip technology. The dataset was randomly separated into a training group and a test group using an R program. In the training group (n=37), a Cox proportional hazards regression model was used to analyse the genes associated with the recurrence and progression‑free survival (PFS) of patients with NFPA. Meanwhile, a random survival forest algorithm, Kaplan‑Meier and receiver operating characteristic curve (ROC) analyses were used to determine the multi‑circRNA signature with the largest area under the ROC curve (AUROC) and verify its efficacy in the test group (n=36). In the training and test groups, the signatures of two circRNAs (hsa_circ_0000066 and hsa_circ_0069707) were specifically associated with the PFS of patients with NFPA (log‑rank P<0.05). Furthermore, the two‑circRNA signature had a high prediction accuracy for tumour recurrence, with an AUROC of 0.87 and 0.67 in the training and test groups, respectively; and the discriminative power of the signature was greater compared with that of age. The present study is the first to suggest a circRNA signature with a clinical application value for predicting recurrence/progression in patients with NFPA.

DNA methylation profiling in nonfunctioning pituitary adenomas

Nonfunctioning pituitary adenomas (NFPAs) are among the most frequent intracranial tumors but their molecular background, including changes in epigenetic regulation, remains poorly understood. We performed genome-wide DNA methylation profiling of 34 NFPAs and normal pituitary samples. Methylation status of the selected genomic regions and expression level of corresponding genes were assessed in a group of 75 patients. NFPAs exhibited distinct global methylation profile as compared to normal pituitary. Aberrant DNA methylation appears to contribute to deregulation of the cancer-related pathways as shown by preliminary functional analysis. Promoter hypermethylation and decreased expression level of SFN, STAT5A, DUSP1, PTPRE and FGFR2 was confirmed in the enlarged group of NFPAs. Difference in the methylation profiles between invasive and non-invasive NFPAs is very slight. Nevertheless, invasiveness-related aberrant epigenetic deregulation of the particular genes was found including upregulation of ITPKB and downregulation CNKSR1 in invasive tumors.

Nonfunctioning Pituitary Adenoma Recurrence and Its Relationship with Sex, Size, and Hormonal Immunohistochemical Profile

BACKGROUND

Tumor recurrence or incomplete resection in nonfunctioning pituitary adenomas (NFPAs) is relatively common. However, predictive factors of tumor recurrence in NFPAs are not well established. We evaluated possible factors related to tumor recurrence in a large cohort of NFPAs at a single pituitary neurosurgery center.

METHODS

A retrospective analysis was conducted of 410 medical records of patients with NFPAs treated by transsphenoidal surgery between 2000 and 2014.

RESULTS

Among the participants, 210 were female (51.0%). A total of 14.1% had giant adenomas. Null-cell pituitary adenomas (n = 239; 58.9%) were the most frequent, followed by silent gonadotroph adenomas (n = 112; 27.3%). Null-cell adenomas were more frequent in women (P = 0.008) and silent gonadotroph adenomas were more frequent in men (P = 0.004). Recurrence was not related to sex or age. Tumor recurrence occurred more often among silent corticotropic adenomas and giant adenomas (hazard ratio 2.45; P < 0.0001 and hazard ratio 2.35; P = 0.001, respectively). Silent thyrotrophic adenoma presented a comparable frequency of recurrence of silent corticotropic adenomas, despite having borderline significance (P = 0.07).

CONCLUSIONS

NFPA tumors have a high heterogeneous hormonal profile and may have prognostic importance. Silent corticotropic adenomas and giant adenomas present a high rate of recurrence.

Immunotherapy and potential molecular targets for the treatment of pituitary adenomas resistant to standard therapy: a critical review of potential therapeutic targets and current developments

INTRODUCTION

Pituitary adenomas (PAs) are primary central nervous system (CNS) tumors, accounting for as much as 25% of intracranial neoplasms. Although existing remedies show success in treating most PAs, treatment of invasive and non-functioning PAs, in addition to functioning PAs unresponsive to standard therapy, remains challenging. With the continually increasing understanding of biochemical pathways involved in tumorigenesis, immunotherapy stands as a promising alternative therapy for pituitary tumors that are resistant to standard therapy.

EVIDENCE ACQUISITION

A literature search was conducted of the PubMed database for immunotherapies of PAs. The search yielded a total of 2621 articles, 26 of which were included in our discussion.

EVIDENCE SYNTHESIS

Several pathologically expressed molecules could potentially serve as promising targets of current or future immunotherapies for PAs. Programmed death ligand-1, matrix metalloproteinases, EpCAM (Trop1) and Trop2, cancer-testis antigen MAGE-A3, epidermal growth factor receptor (EGFR), folate receptor alpha, vascular endothelial growth factor, and galectin-3 have all been implicated as crucial factors involved with tumor survival and invasion. Inhibition of these pathways may prove efficacious in the management of invasive and treatment-resistant PAs.

CONCLUSIONS

Rapid advancements in tumor immunology may increase the probability of successful treatment of PAs by exploitation of the normal immune response or by targeting novel proteins. Current research on many of the targets reviewed in this article are successfully being utilized to manage various neoplastic disease including CNS tumors. These therapies may eventually play a key role in the treatment of PAs that do not respond to standard therapy.

Complete evaluation of pituitary tumours in a single tertiary care institution

INTRODUCTION

We retrospectively evaluated all patients with pituitary tumours treated in our department from 1/1/1997 to 01/11/2014.

PATIENTS AND METHODS

Two hundred and fifteen patients (124 females, 91 males, mean age 50.9 years) were treated because of pituitary tumours. All patients underwent basal hormonal analysis and when required dynamic testing in order to check for hormonal activity. Pituitary masses were divided into groups concerning their hormonal status and were further classified according to gender, age at diagnosis, tumour size, and the development of postoperative pituitary insufficiency when neurosurgical intervention was conducted.

RESULTS

One hundred and twenty-one patients had hormonally inactive tumours (non-functional adenomas; 56.3%), 57 prolactinomas (26.5%), 17 growth hormone secreting adenomas (7.9%), 16 Cushing's disease (7.4%), and 4 craniopharyngiomas (1.9%). Tumours with maximum size <1 cm (microadenomas) were detected in 62 patients (28.8%) and ≥1 cm (macroadenomas) in 153 (71.2%) of all cases (rate 1:2.5). Ninty eight patients (45.6%) had surgery (87 transsphenoidal and 11 transcranial), of this group 34 with hormonally active tumours (37.8% of the 90 patients of this subcohort). Indications for surgery were an increased risk or manifestation of chiasma syndrome and clinical symptoms due to hormonal hypersecretion. Complete [32 cases (32.6%)] or partial [33 cases (33.7%)] postoperative insufficiency in minimum one pituitary axis was present in 65/98 (66.3%) of the operated patients.

CONCLUSIONS

Pituitary adenoma prevalence is rising due to widely available imaging procedures. The majority of the tumours in our cohort were macroadenomas and hormonally inactive. Tumour extirpation via the transsphenoidal or transcranial route resulted in functional pituitary impairment of variable extent in 2/3 of the patients.

Epidemiology, clinical presentation and diagnosis of non-functioning pituitary adenomas

PURPOSE

Non-functioning pituitary adenomas (NFPAs) are benign pituitary neoplasms that do not cause a hormonal hypersecretory syndrome. An improved understanding of their epidemiology, clinical presentation and diagnosis is needed.

METHOD

A literature review was performed using Pubmed to identify research reports and clinical case series on NFPAs.

RESULTS

They account for 14-54% of pituitary adenomas and have a prevalence of 7-41.3/100,000 population. Their standardized incidence rate is 0.65-2.34/100,000 and the peak occurence is from the fourth to the eighth decade. The clinical spectrum of NFPAs varies from being completely asymptomatic to causing significant hypothalamic/pituitary dysfunction and visual field compromise due to their large size. Most patients present with symptoms of mass effect, such as headaches, visual field defects, ophthalmoplegias, and hypopituitarism but also hyperprolactinaemia due to pituitary stalk deviation and less frequently pituitary apoplexy. Non-functioning pituitary incidentalomas are found on brain imaging performed for an unrelated reason. Diagnostic approach includes magnetic resonance imaging of the sellar region, laboratory evaluations, screening for hormone hypersecretion and for hypopituitarism, and a visual field examination if the lesion abuts the optic nerves or chiasm.

CONCLUSION

This article reviews the epidemiology, clinical behaviour and diagnostic approach of non-functioning pituitary adenomas.

Management of NFAs: medical treatment

INTRODUCTION

Non-functioning pituitary adenomas (NFPAs) are in general large tumors that present with symptoms secondary to local pressure on adjacent structures. Transsphenoidal surgery is the first line of treatment but residual tumor mass is often detected post-operatively. Medical therapy, in any stage of tumor management, is not well established.

METHODS

A literature search was performed to review the available data on medical treatment of NFPAs.

RESULTS

Medications investigated for the treatment of NFPAs include dopamine receptor agonists (DA) and somatostatin receptor ligands. Randomized controlled trials are lacking, but available data suggest that DA have a positive effect on tumor remnant stabilization after surgery and could be considered in this setting. Temozolomide is reserved for aggressive tumors, although future studies are required.

CONCLUSIONS

NFPA are often not amenable to complete surgical resection. Conservative follow-up after surgery is associated with a high prevalence of tumor remnant progression. DA therapy may prevent residual tumor enlargement in over 85% of these patients, with a substantial consequent reduction in the need for repeat surgery or radiation therapy. It is our view that DA treatment should be routinely considered for the management of NFPA patients with incompletely resected tumors.

Non-invasive radiomics approach potentially predicts non-functioning pituitary adenomas subtypes before surgery

PURPOSE

To make individualised preoperative prediction of non-functioning pituitary adenoma (NFPAs) subtypes between null cell adenomas (NCAs) and other subtypes using a radiomics approach.

METHODS

We enrolled 112 patients (training set: n = 75; test set: n = 37) with complete T1-weighted magnetic resonance imaging (MRI) and contrast-enhanced T1-weighted MRI (CE-T1). A total of 1482 quantitative imaging features were extracted from T1 and CE-T1 images. Support vector machine trained a predictive model that was validated using a receiver operating characteristics (ROC) analysis on an independent test set. Moreover, a nomogram was constructed incorporating clinical characteristics and the radiomics signature for individual prediction.

RESULTS

T1 image features yielded area under the curve (AUC) values of 0.8314 and 0.8042 for the training and test sets, respectively, while CE-T1 image features provided no additional contribution to the predictive model. The nomogram incorporating sex and the T1 radiomics signature yielded good calibration in the training and test sets (concordance index (CI) = 0.854 and 0.857, respectively).

CONCLUSION

This study focused on the preoperative prediction of NFPA subtypes between NCAs and others using a radiomics approach. The developed model yielded good performance, indicating that radiomics had good potential for the preoperative diagnosis of NFPAs.

KEY POINTS

• MRI may help in the pre-operative diagnosis of NFPAs subtypes • Retrospective study showed T1-weighted MRI more useful than CE-T1 in NCAs diagnosis • Treatment decision making becomes more individualised • Radiomics approach had potential for classification of NFPAs.

MANAGEMENT OF ENDOCRINE DISEASE: Present and future perspectives for medical therapy of nonfunctioning pituitary adenomas

In contrast to the clear indication for surgical treatment in symptomatic patients with clinically nonfunctioning pituitary adenomas (NFPA), there are no randomized controlled studies comparing therapeutic strategies such as watchful waiting, irradiation or medical therapy for the management of NFPA after surgery. Further, no medical therapy is currently approved for the treatment of NFPA. In this review, we summarize accumulating data on medications currently approved for secreting pituitary adenomas, used off-label in patients with NFPA. Perspectives on overall treatment optimization and potential future therapies are also detailed.

Contribution of molecular analysis to the typification of the non-functioning pituitary adenomas

AIM

The WHO Classification of Tumours of Endocrine Organs considers the inmunohistochemical characterization of pituitary adenomas (PA) as mandatory for patient diagnosis. Recent advances in the knowledge of the molecular patterns of these tumours could complement this classification with gene expression profiling.

METHODS

Within the context of the Spanish Molecular Registry of Pituitary Adenomas (REMAH), a multicentre clinical-basic research project, we analysed the molecular phenotype of 142 PAs with complete IHC and clinical information. Gene expression levels of all pituitary hormones, type 1 corticotrophin-releasing hormone receptor, dopamine receptors and arginine vasopressin receptor 1b were measured by quantitative real-time polymerase chain reaction. In addition, we used three housekeeping genes for normalization and a pool of nine healthy pituitary glands from autopsies as calibration reference standard.

RESULTS

Based on the clinically functioning PA (FPA: somatotroph, corticotroph, thyrotroph and lactotroph adenomas), we established the interquartile range of relative expression for all genes studied in each PA subtype. That allowed molecularly the different PA subtypes, including the clinically non-functioning PA (NFPA). Afterwards, we estimated the concordance of the molecular and immunohistochemical classification with clinical diagnosis in FPA and between them in NFPA. The kappa values were higher in molecular than in immunohistochemical classification in FPA and showed a bad concordance in all NFPA subtypes.

CONCLUSIONS

According to these results, the molecular characterization of the PA complements the IHC analysis, allowing a better typification of the NFPA.

Differential expression of the Notch1 receptor, and its ligands Dll1, Dll3 and Dll4 in distinct human pituitary adenoma subtypes

Pituitary adenoma (PA) is a common type of benign tumor of the pituitary gland that is characterized by specific signs and symptoms, primarily associated with hypersecretion of pituitary glycoprotein hormones (thyroid-stimulating, growth and adrenocorticotrophic hormones, and prolactin). Surgery is the first-line treatment, although postoperative residual tissues/cells and subsequent recurrence remain notable complications. Gene therapy is an effective approach for treatment, as previous studies have demonstrated that the Notch signaling pathway participates in the pathogenesis of PA. The focus of the present study was on the associations between the expression of the Notch1 receptor and its ligands δ-like canonical Notch ligand (Dll) 1, Dll3 and Dll4 in patients with PA. Using reverse transcription-quantitative polymerase chain reaction and western blot analyses, to the best of our knowledge, this is the first study to provide a description of the differential expression of the Notch1 receptor and its ligands Dll1, Dll3, and Dll4 in various types of human PA at the mRNA and protein levels. The results of the present study demonstrated that Notch1 protein expression was positively correlated with Dll4 protein expression, but negatively correlated with Dll3 protein expression, indicating synergistic effects between the Notch1 receptor and Dll4 ligand. Furthermore, the Dll3 ligand may be an inhibitor of the Notch1 receptor, indicating an antagonistic association between Notch1 and the Dll3 ligand. These results have identified a potential target for the treatment of patients with PA.

Novel aspects in histopathology of the pituitary gland

The sellar and parasellar region is a complex anatomical area in which several diseases may develop. The pituitary gland may be affected by a wide range of conditions having similar clinical characteristics. Diagnosis of these lesions requires a multidisciplinary approach including, in addition to clinical, laboratory, imaging, and surgical findings, histological diagnosis of pituitary adenomas to guide therapeutic management. As the result of development in recent years of new immunohistochemical techniques, histopathological classification has become more complex and wide, and not only continues to be the gold standard in diagnosis, but also has prognostic implications. The aim of this review is to provide a clear and simple update of the main concepts of histological diagnosis of the most common pituitary conditions, especially for professionals in direct contact with such diseases.

Novel aspects in histopathology of the pituitary gland

The sellar and parasellar region is a complex anatomical area in which several diseases may develop. The pituitary gland may be affected by a wide range of conditions having similar clinical characteristics. Diagnosis of these lesions requires a multidisciplinary approach including, in addition to clinical, laboratory, imaging, and surgical findings, histological diagnosis of pituitary adenomas to guide therapeutic management. As the result of development in recent years of new immunohistochemical techniques, histopathological classification has become more complex and wide, and not only continues to be the gold standard in diagnosis, but also has prognostic implications. The aim of this review is to provide a clear and simple update of the main concepts of histological diagnosis of the most common pituitary conditions, especially for professionals in direct contact with such diseases.

Treatment of Nonfunctional Pituitary Adenoma Postoperative Remnants: Adjuvant or Delayed Gamma Knife Radiosurgery?

OBJECTIVE

It is still not clear whether Gamma Knife radiosurgery (GKRS) for nonfunctional pituitary adenomas should be used as a standard adjuvant postoperative therapy or applied when there is documented progression of the remnant on follow-up magnetic resonance imaging.

METHODS

We performed a retrospective study of patients with nonfunctional pituitary adenomas who underwent primary surgery and GKRS between 2002 and 2015. Patients were divided into 2 groups on the basis of the GKRS indication: adjuvant treatment (GKRS ≤6 months postoperatively) or delayed treatment (GKRS if documented progression occurred on the follow-up magnetic resonance imaging).

RESULTS

Fifty patients were included and grouped based on adjuvant (n = 13) or delayed (n = 37) GKRS following primary surgery. The adjuvant and delayed groups had 10-year actuarial tumor control rates of 92% and 96% (P = 0.408), respectively. The 10-year actuarial endocrinologic control rate was 82% for the adjuvant group and 49% for the delayed group (P = 0.597). None of the patients developed any new neurologic deficit post-GKRS. GKRS-induced complications (intratumoral bleeding and tumoral tissue inflammation) occurred in 6% of the patients, of whom 4% were in the delayed group and 2% in the adjuvant group.

CONCLUSION

Adjuvant treatment with GKRS yields the same high long-term tumor control as delayed GKRS. Neither adjuvant nor delayed GKRS induced additional neurologic complications. There is a trend that adjuvant GKRS induces less additional endocrinologic deficits compared with delayed GKRS.

A Novel Invasive-Related Biomarker in Three Subtypes of Nonfunctioning Pituitary Adenomas

OBJECTIVE

To identify biomarkers key to invasiveness of the 3 subtypes of nonfunctioning pituitary adenomas (NFPAs) and provide a guidance for therapeutic decision making and identification of potential adjuvant drugs.

METHODS

Fifty NFPA tumor tissues obtained from transsphenoidal surgery were used in the study. Three invasive NFPAs and 4 noninvasive NFPAs were used for gene expression microarray analyses. In addition, there are 5 invasive NFPAs and 4 noninvasive NFPAs used for proteomic analyses. Invasive-related biomarkers were identified by bioinformatics analysis by integrating the transcriptomics and proteomics data sets. All 3 subtypes of NFPAs (null cell adenomas, oncocytomas, and gonadotroph adenomas) were used to validate differentially expressed candidate biomarkers by means of quantitative real-time reverse transcription polymerase chain reaction and Western blot. The level of EZR was downregulated in pituitary adenoma cell line GH3 to investigate the invasive effect of EZR on GH3 cells by using the RNA interference technique.

RESULTS

Eight genes involved in the invasion function were found by bioinformatics analysis, and the EZR gene was identified as a novel invasive-related biomarker in the 3 subtypes of NFPAs. The expression level of EZR was found higher in terms of invasiveness than the noninvasive ones of the 3 subtypes of NFPAs. Moreover, the knockdown of EZR inhibited the invasion of GH3 cells in vitro.

CONCLUSIONS

EZR is a novel biomarker in terms of invasion among the 3 subtypes of NFPAs, and it is a promising guide for therapeutic decision making as well.

Life expectancy in patients with pituitary adenoma receiving growth hormone replacement

OBJECTIVE

Hypopituitarism has been associated with increased mortality. The excess mortality may be due to untreated growth hormone (GH) deficiency but also due to various underlying disorders. We therefore analysed mortality in patients with only one underlying disorder, non-functioning pituitary adenoma (NFPA), with and without GH replacement therapy (GHRT).

DESIGN AND METHOD

Patients with NFPA in the western region of Sweden, 1997-2011, were identified through the National Patient Registry and cross-referenced with several National Health Registries. All patient records were reviewed. Standardised mortality ratios (SMRs) with 95% confidence intervals (CIs) were calculated using the general population as reference. Cox-regression models were performed to identify predictors of mortality.

RESULTS

A total of 426 NFPA patients with 4599 patient-years were included, of whom 207 had used GHRT and 219 had not received GHRT. Median (range) follow-up in patients with and without GHRT was 12.2 (0-25) and 8.2 (0-27) years, respectively. Other pituitary hormone deficiencies were more frequent in the GHRT group than those in the non-GHRT group. SMR was 0.65 (95% CI, 0.44-0.94; P = 0.018) for the GHRT group and 1.16 (0.94-1.42; P = 0.17) for the non-GHRT group. Direct comparison between the groups showed reduced mortality among those who were GH replaced (P = 0.0063). The SMR for malignant tumours was reduced in the GHRT-group (0.29; 0.08-0.73; P = 0.004) but not in untreated patients.

CONCLUSIONS

Selection bias explaining some of the results cannot be excluded. However, NFPA patients with GHRT had reduced overall mortality compared with the general population, and death due to malignancy was not increased. This suggests that long-term GHRT is safe in adult patients selected for treatment.

Endoscopic Versus Microscopic Transsphenoidal Approach for Pituitary Adenomas: Comparison of Outcomes During the Transition of Methods of a Single Surgeon

OBJECTIVE

The transition from microscopic to fully endoscopic transsphenoidal surgery requires a surgeon to assess how the change in technique will affect the extent of tumor resection (EOR), outcomes, and complications. We compared a single surgeon's experience transitioning from one technique to the other and examined the operative outcomes and EOR between microscopic versus endoscopic transsphenoidal surgery.

METHODS

Retrospective data analysis of adult patients who were treated surgically for a pituitary adenoma between August 2005 and May 2015 by a single neurosurgeon, who was originally trained and practiced in the microscopic transsphenoidal approach. Patient demographics, perioperative conditions, tumor characteristics, operative times, volumetric EOR, postoperative outcome, and the endoscopic learning curve were evaluated.

RESULTS

One hundred and nine patients underwent microscopic transsphenoidal surgery and 275 patients underwent a fully endoscopic approach. The patient characteristics were similar in the 2 groups. Operative room time was significantly shorter in the endoscopic group than in the microscopic group (180.2 vs. 215.6 minutes; P < 0.001). The endoscopic and microscopic groups had similar volumetric EOR (85.1% vs. 82.8%; P = 0.371) as well as residual tumor volume (1.06 cm³ vs. 1.15 cm³; P = 0.765). The mean length of hospital stay was 2.4 days in the endoscopic group and 3.2 days in the microscopic group (P = 0.03).

CONCLUSIONS

During the transition from the microscopic to the endoscopic approach, similar surgical outcomes and EOR were achieved in the 2 cohorts. In our experience, the endoscopic approach offers the advantage of shorter operative times and lengths of hospital stays after the surgeon has developed more experience with the technique.

Geographic variation in cost of care for pituitary tumor surgery

PURPOSE

Geography is known to affect cost of care in surgical procedures. Understanding the relationship between geography and hospital costs is pertinent in the effort to reduce healthcare costs. We studied the geographic variation in cost for transsphenoidal pituitary surgery in hospitals across New York State.

METHODS

Using the Healthcare Cost and Utilization Project State Inpatient Database for New York from 2008 to 2011, we analyzed records of patients who underwent elective transsphenoidal pituitary tumor surgery and were discharged to home or self-care. N.Y. State was divided into five geographic regions: Buffalo, Rochester, Syracuse, Albany, and Downstate. These five regions were compared according to median charge and cost per day.

RESULTS

From 2008 to 2011, 1803 transsphenoidal pituitary tumor surgeries were performed in New York State. Mean patient age was 50.7 years (54 % were female). Adjusting prices for length of stay, there was substantial variation in prices. Median charges per day ranged from $8485 to $13,321 and median costs per day ranged from $2962 to $6837 between the highest and lowest regions from 2008 to 2011.

CONCLUSION

Within New York State, significant geographic variation exists in the cost for transsphenoidal pituitary surgery. The significance of and contributors to such variation is an important question for patients, providers, and policy makers. Transparency of hospital charges, costs, and average length of stay for procedures to the public provides useful information for informed decision-making, especially for a highly portable disease entity like pituitary tumors.