Can we ever stop imaging in surgically treated and radiotherapy-naive patients with non-functioning pituitary adenoma?

Comparative analysis of intraoperative and imaging features of invasive growth in pituitary adenomas

BACKGROUND

Most pituitary adenomas (PAs), also termed pituitary neuroendocrine tumors, are benign in nature and can be treated effectively by surgical resection, medical treatment, and in special cases by radiotherapy. However, invasive growth can be an important feature of a more aggressive behavior and adverse prognosis. The extension of PAs into the cavernous sinus can be categorized according to the Knosp criteria on magnetic resonance imaging (MRI). Comparative analyses of MRI features and intraoperative findings of invasive growth regarding different clinical factors are still scarce.

MATERIALS AND METHODS

We performed a retrospective single-center analysis of 764 PAs that were surgically treated between October 2004 and April 2018. Invasive growth was assessed according to the surgical reports and preoperative MRI (Knosp criteria). Clinical data, such as patient age at diagnosis and gender, histopathological adenoma type, and extent of resection, were collected.

RESULTS

Invasive features on MRI were seen in 24.4% (Knosp grades 3A-4, 186/764) of the cases. Intraoperatively, invasion was present in 42.4% (324/764). Complete resection was achieved in 80.0% of adenomas and subtotal resection, in 20.1%. By multivariate analysis, invasion according to intraoperative findings was associated with the sparsely granulated corticotroph (SGCA, P = .0026) and sparsely granulated somatotroph (SGSA, P = .0103) adenoma type as well as age (P = .0287). Radiographic invasion according to Knosp grades 3A-4 correlated with age (P = .0098), SGCAs (P = .0005), SGSAs (P = .0351), and gonadotroph adenomas (P = .0478). Both criteria of invasion correlated with subtotal resection (P = .0001, respectively).

CONCLUSIONS

Both intraoperative and radiographic signs of invasive growth are high-risk lesions for incomplete extent of resection and occur more frequently in older patients. A particularly high prevalence of invasion can be found in the SGCA and SGSA types. Cavernous sinus invasion is also more common in gonadotroph adenomas. Usage of the Knosp classification is a valuable preoperative estimation tool.

How often should we perform magnetic resonance imaging (MRI) for the follow-up of pituitary adenoma?

Magnetic resonance imaging (MRI) is the examination of choice for diagnosing and monitoring pituitary adenoma (also known as pituitary neuroendocrine tumor or PitNET), whether treated or not. However, repeating the examination too often (and sometimes unnecessarily) is costly, and worrying data on tissue accumulation (brain, bone, etc.) of gadolinium atoms dissociated from their carrier molecule (chelator) have led European authorities to ban contrast agents based on linear chelators of gadolinium, which are particularly susceptible to rapid dissociation, in favor of chemically more stable macrocyclic chelators. It is therefore important to determine the optimal frequency for pituitary MRI monitoring in order to safely assess the natural history or therapeutic response of pituitary adenomas. The aim of this article is to summarize the most recent data on optimal follow-up intervals depending on the type, size and location of the pituitary tumor and the clinical situation in general, in order to generate monitoring algorithms to guide clinicians.

Surveillance Imaging Strategies for Pituitary Adenomas: When, How Frequent, and When to Stop

OBJECTIVE

To describe a practical approach of when and how often to perform imaging, and when to stop imaging pituitary adenomas (PAs).

METHODS

A literature review was carried out and recommendations provided are derived largely from personal experience.

RESULTS

Magnetic resonance imaging is the mainstay imaging modality of choice in the assessment, treatment planning, and follow-up of PAs. These adenomas are discovered incidentally during imaging for a variety of unrelated conditions, because of clinical symptoms related to mass effects on the adjacent structures, or during workup for functional alterations of the adenoma. Imaging is also used in the preoperative and postoperative phases of assessment of PAs, for surgical and radiotherapy planning, for postoperative surveillance to assess for adenoma stability and detection of adenoma recurrence, and for surveillance to monitor for adenoma growth in unoperated PAs. Currently, because there are no evidence-based consensus recommendations, the optimal strategy for surveillance imaging of PAs is not clearly established. Younger age, initial adenoma size, extrasellar extension, mass effect, cavernous sinus invasion, functional status, histopathologic characteristics, cost considerations, imaging accessibility, patient preference, and patient contraindications (eg, implanted metallic devices and patient claustrophobia) are all important factors that influence the strategy for surveillance imaging.

CONCLUSIONS

This review provides a practical approach of performing surveillance imaging strategies for PAs that should be individualized based on clinical presentation, history, adenoma morphology on imaging, and histopathologic characteristics.

Comparing redo surgery and stereotactic radiosurgery for recurrent, residual, and/or tumors showing progression in nonfunctioning pituitary adenomas: A systematic review and meta-analysis

Background

Non-functioning pituitary adenomas (NFPAs) are well-differentiated benign tumors originating from the adenohypophyseal cells of the pituitary gland. They present with headaches, visual disorders, or cranial nerve deficits. NFPAs can recur, progress, or present as residual tumors. We, therefore, conducted this review to compare the effects of both revision surgery and stereotactic surgery on tumor size, visual status, endocrine status, and complications.

Methods

A systematic review of published literature on recurrent, residual, or progressing NFPAs that underwent redo surgery or stereotactic radiosurgery from the inception till June 2020 was conducted as per Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Thirteen records (1209 patients) were included, and risk ratio (RR) and 95% confidence intervals (CIs) estimated from each study were pooled using a random-effects meta-analysis model.

Results

Redo surgery was the preferred intervention in patients presenting with larger tumor sizes and was more effective in reducing the tumor size as compared to stereotactic radiosurgery (SRS) (risk ratio [RR] 56.14; 95% CI, 16.45-191.58). There was more visual loss with revision surgery as compared to SRS (risk ratio [RR] 0.08; 95% CI, 0.03-0.20). However, SRS was associated with fewer complications, such as new diabetes insipidus, as compared to the redo surgery (risk ratio [RR] 0.01; 95% CI 0.01-0.03).

Conclusion

Redo surgery is the superior choice in the treatment of recurrent/residual or progressing NFPAs if the tumor size is large and an immediate reduction in tumor burden through debulking is warranted. However, redo surgery is associated with a higher risk of visual loss, new endocrinopathies, and other complications, in contrast to SRS.

Pharmacological Treatment of Non-Functioning Pituitary Adenomas

Treatment strategies for NFPA include surgery, radiotherapy, medical treatment, or follow-up. The treatment of NFPAs with compressive symptoms is surgical. However, in case of post-surgical tumor remnants, there may be treatment strategies that include observation and radiotherapy. Recently, medical treatment with cabergoline (CAB) has been recommended to contain and/or reduce the size of the tumor remnant. Based on the findings that many NFPAs show a dopamine receptor (DR) and somatostatin receptor (SR) expression, medical therapy with dopamine agonists (DAs) and somatostatin receptor ligands (SSRLs) has been tested as an alternative to prevent recurrence after surgery. The DAs have been the most extensively studied, showing some potential in terms of tumor shrinkage. SSRLs and other emerging medical options are much less studied. We will review and critically evaluate the current data on the medical therapy of NFPAs to elucidate their role in the management of this tumor type. In the case of actively growing remnants (more than 10% growth per year) and high-risk pituitary adenomas, treatment with CAB at a dose of 1.5-3.0 mg is indicated for tumor containment and/or reduction. In relation to combined chemotherapy with CAB, there is little information in the literature to support its use. In our experience, CAB treatment can be used after radiotherapy as an adjuvant treatment.

The clinicopathological features and prognosis of silent corticotroph tumors: an updated systematic review and meta-analysis

INTRODUCTION

Data on silent corticotroph tumor (SCT) are still heterogeneous and controversial. In this study, we aimed to compare the demographic, clinicopathological manifestations, postoperative complications, and patient outcomes of SCTs with other non-functioning pituitary neuroendocrine tumor (NFT) and functioning corticotroph tumor (FCT) or so-called Cushing disease adenoma.

METHODS

We searched PubMed and Web of Science for data of interest. Odds ratio (OR), mean difference (MD), hazard ratio (HR), and their 95% confidence intervals (CI) were pooled using the random-effect model.

RESULTS

Twenty-nine studies with 985 SCTs were included in meta-analyses. In comparison to other NFTs, SCTs were more commonly associated with female gender, younger age, cavernous sinus invasion, apoplexy, and radiotherapy administration. Postoperatively, SCT patients were more likely to experience hypocortisolism, new-onset visual disturbances, and a higher risk for tumor progression than other NFTs. We did not find any significant differences between SCT type I and type II. Compared to FCTs, SCTs were more likely male, older age, and had larger tumor sizes. The prevalence of a USP8 mutation was significantly higher in FCT than in SCT.

CONCLUSION

SCT was demographically, clinicopathologically, and prognostically distinct from other NFTs and FCTs. These tumors should be considered high-risk; appropriate treatment decisions and more stringent follow-up should be tailored to improve patient outcomes.

Natural history of post-operative non-functioning pituitary adenomas - a single centre cohort analysis

PURPOSE

To study behaviour of endonasally operated non-functioning pituitary adenomas (NFPA) and propose a cost-effective stratified follow-up regimen.

METHODS

A single centre retrospective cohort analysis from June 2009 till December 2019. All endonasally operated pituitary adenomas were identified with sub-analysis of the NFPA's. Patients of all age groups with radiological follow-up more than 30 months were included. Patients with any kind of cranial intervention performed < within 30 months of surgery were excluded. The post-operative MRI for this cohort was evaluated until either any intervention was performed or until the last follow-up. The maximal tumour diameter in any plane (mm) was measured from the MRI scans. The annual growth rate and the statistical relationship between age, sex, IHC, Ki-67, resection %, residual tumour was calculated.

RESULTS

Out of 610 pituitary adenomas identified in the dataset, 116 patients met the inclusion criteria. Follow-up period ranged from 30 to 142 months (mean 78.5 months). A strong relationship existed between predicting tumour progression with first post-operative residue size (p = .001). A statistically significant relationship was found to be present between tumour growth and a residue of less than 10 mm diameter and 11-20 mm in diameter (Log rank p value .0216). On average, each patient with a residue < 5mm had MRI scans costing 976 £.

CONCLUSION

Based on statistical analysis and internal validation of the growth rate of the residue, we have proposed MRI follow-up scans. These recommendations have the potential to save more than 300 £per patient towards MRI costs and can lay down a marker for defining time interval of serial scans for post-operative NFPA's.

Non-functioning pituitary macroadenoma following surgery: long-term outcomes and development of an optimal follow-up strategy

Objectives

Recurrence and regrowth of non-functioning pituitary macroadenomas (NFPMs) after surgery are common but remain unpredictable. Therefore, the optimal timing and frequency of follow-up imaging remain to be determined. We sought to determine the long-term surgical outcomes of NFPMs following surgery and develop an optimal follow-up strategy.

Methods

Patients underwent surgery for NFPMs between 1987 and 2018, with a follow-up of 6 months or more, were identified. Demographics, presentation, management, histology, imaging, and surgical outcomes were retrospectively collected.

Results

In total, 383 patients were included; 256 were men (256/383; 67%) with median follow-up of 8 years. Following primary surgery, 229 patients (229/383; 60%) achieved complete resection. Of those, 28 (28/229; 11%) developed recurrence, including six needed secondary surgery (6/229; 3%). The rate of complete resection improved over time; in the last quartile of cases, 77 achieved complete resection (77/95; 81%). Reoperation-free survival at 5, 10 and 15 years was 99%, 94% and 94%, respectively. NFPMs were incompletely resected in 154 patients (154/383; 40%); of those, 106 (106/154; 69%) had regrowth, and 84 (84/154; 55%) required reoperation. Surgical reintervention-free survival at 5, 10 and 15 years was 74%,49% and 35%, respectively. Young age and cavernous sinus invasion were risk factors for undergoing reoperation (P < 0.001 and P < 0.0001, respectively) and radiotherapy (P = 0.003 and P < 0.001, respectively). Patients with residual tumour required reoperation earlier than those underwent complete resection (P = 0.02). Radiotherapy to control tumour regrowth was delivered to 65 patients (65/383; 17%) after median time of 1 year following surgery. Radiotherapy was administered more in patients with regrowth of residual disease (61/106; 58%) than those who had NFPMs recurrence (4/28; 14%) (P ≤ 0.001) Following postoperative radiotherapy, one patient (1/65; 2%) had evidence of regrowth, seven (7/65; 11%) had tumour regression on imaging, and no patients underwent further surgery.

Conclusions

NFPMs recurrence and regrowth are common, particularly in patients with residual disease post-operatively. We propose a follow-up strategy based on stratifying patients as "low risk" if there is no residual tumour, with increasing scan intervals, or "high risk" if there is a residual tumour, with annual scans for at least five years and extended lifelong surveillance after that.

Postsurgical outcomes of nonfunctioning pituitary adenomas: a patient-level meta-analysis

BACKGROUND

Surgical resection is the main treatment for symptomatic nonfunctioning pituitary adenomas (NFPA). We aimed to analyze the impact of surgical approach, completeness of resection, and postoperative radiotherapy on long-term progression-free survival (PFS) of NFPA, using individual patient data (IPD) meta-analysis.

METHODS

An electronic literature searched was conducted on PubMed, EMBASE, and Web of Science from database inception to 6 November 2022. Studies describing the natural history of surgically resected NFPA, with provision of Kaplan-Meier curves, were included. These were digitized to obtain IPD, which was pooled in one-stage and two-stage meta-analysis to determine hazard ratios (HRs) and 95%CIs of gross total resection (GTR) versus subtotal resection (STR), and postoperative radiotherapy versus none. An indirect analysis of single-arm data between endoscopic endonasal (EES) and microscopic transsphenoidal (MTS) surgical technique was also performed.

RESULTS

Altogether, eleven studies (3941 patients) were retrieved. PFS was significantly lower in STR than GTR (shared-frailty HR 0.32, 95%CI 0.27-0.39, p < 0.001). Postoperative radiotherapy significantly improved PFS compared to no radiotherapy (shared-frailty HR 0.20, 95%CI 0.15-0.26, p < 0.001), including in the subgroup of patients with STR (shared-frailty HR 0.12, 95%CI 0.08-0.18, p < 0.001). Similar PFS was observed between EES and MTS (indirect HR 1.09, 95%CI 0.92-1.30, p = 0.301).

CONCLUSIONS

This systematic review and patient-level meta-analysis provides a robust prognostication of surgically treated NFPA. We reinforce current guidelines stating that GTR should be the standard of surgical resection. Postoperative radiotherapy is of considerable benefit, especially for patients with STR. Surgical approach does not significantly affect long-term prognosis.

REGISTRATION

PROSPERO CRD42022374034.

Identification of a Novel SSTR3 Full Agonist for the Treatment of Nonfunctioning Pituitary Adenomas

Somatostatin receptor (SSTR) agonists have been extensively used for treating neuroendocrine tumors. Synthetic therapeutic agonists showing selectivity for SSTR2 (Octreotide) or for SSTR2 and SSTR5 (Pasireotide) have been approved for the treatment of patients with acromegaly and Cushing's syndrome, as their pituitary tumors highly express SSTR2 or SSTR2/SSTR5, respectively. Nonfunctioning pituitary adenomas (NFPAs), which express high levels of SSTR3 and show only modest response to currently available SSTR agonists, are often invasive and cannot be completely resected, and therefore easily recur. The aim of the present study was the evaluation of ITF2984, a somatostatin analog and full SSTR3 agonist, as a new potential treatment for NFPAs. ITF2984 shows a 10-fold improved affinity for SSTR3 compared to Octreotide or Pasireotide. Molecular modeling and NMR studies indicated that the higher affinity for SSTR3 correlates with a higher stability of a distorted β-I turn in the cyclic peptide backbone. ITF2984 induces receptor internalization and phosphorylation, and triggers G-protein signaling at pharmacologically relevant concentrations. Furthermore, ITF2984 displays antitumor activity that is dependent on SSTR3 expression levels in the MENX (homozygous mutant) NFPA rat model, which closely recapitulates human disease. Therefore, ITF2984 may represent a novel therapeutic option for patients affected by NFPA.

The Emerging Role of m6A Modification in Endocrine Cancer

With the development of RNA modification research, N6-methyladenosine (m6A) is regarded as one of the most important internal epigenetic modifications of eukaryotic mRNA. It is also regulated by methylase, demethylase, and protein preferentially recognizing the m6A modification. This dynamic and reversible post-transcriptional RNA alteration has steadily become the focus of cancer research. It can increase tumor stem cell self-renewal and cell proliferation. The m6A-modified genes may be the primary focus for cancer breakthroughs. Although some endocrine cancers are rare, they may have a high mortality rate. As a result, it is critical to recognize the significance of endocrine cancers and identify new therapeutic targets that will aid in improving disease treatment and prognosis. We summarized the latest experimental progress in the m6A modification in endocrine cancers and proposed the m6A alteration as a potential diagnostic marker for endocrine malignancies.

Post-operative surveillance for somatotroph, lactotroph and non-functional pituitary adenomas after curative resection: a systematic review

CONTEXT

Pituitary tumors are the third most common brain tumor and yet there is no standardization of the surveillance schedule and assessment modalities after transsphenoidal surgery.

EVIDENCE ACQUISITION

OVID, EMBASE and the Cochrane Library databases were systematically screened from database inception to March 5, 2020. Inclusion and exclusion criteria were designed to capture studies examining detection of pituitary adenoma recurrence in patients 18 years of age and older following surgical resection with curative intent.

EVIDENCE SYNTHESIS

A total of 7936 abstracts were screened, with 812 articles reviewed in full text and 77 meeting inclusion criteria for data extraction. A pooled analysis demonstrated recurrence rates at 1 year, 5 years and 10 years for non-functioning pituitary adenomas (NFPA; N = 3533 participants) were 1%, 17%, and 33%, for prolactin-secreting adenomas (PSPA; N = 1295) were 6%, 21%, and 28%, and for growth-hormone pituitary adenomas (GHPA; N = 1257) were 3%, 8% and 13%, respectively. Rates of recurrence prior to 1 year were 0% for NFPA, 1-2% for PSPA and 0% for GHPA. The mean time to disease recurrence for NFPA, PSPA and GHPA were 4.25, 2.52 and 4.18 years, respectively.

CONCLUSIONS

This comprehensive review of the literature quantified the recurrence rates for commonly observed pituitary adenomas after transsphenoidal surgical resection with curative intent. Our findings suggest that surveillance within 1 year may be of low yield. Further clinical trials and cohort studies investigating cost-effectiveness of surveillance schedules and impact on quality of life of patients under surveillance will provide further insight to optimize follow-up.

Case report: Clinical report of co-occurrence of pituitary adenoma and meningioma in the sellar region after meningioma treatment

The coexistence of meningioma and pituitary adenoma is very rare, especially in the same location after meningioma surgery. Here, we reported a case of coexisting meningioma and pituitary adenoma secondary to postoperative meningioma in the sellar region in a patient who had not received radiation therapy before the second surgery. A 61-year-old woman underwent craniotomy for tumor resection for sellar meningioma in 2017, and postoperative imaging showed no residual in the surgical area. In 2022, the patient had a history of decreased vision again. MRI showed the possibility of postoperative pituitary adenoma in the sellar region. The patient underwent endoscopic resection of the skull base lesion again. After surgery, the patient's visual symptoms improved. Histology of the sellar tumor showed both meningioma (meningeal epithelial type and WHO grade I) and pituitary adenoma in the same section. The coexistence of meningioma and pituitary adenoma is a very rare surgical entity. This report provides a theoretical basis for the selection of intracerebral tumor surgery and provides a diagnostic basis and treatment reference for patients diagnosed with meningioma and pituitary adenoma at the same time.

Recurrence Rate and Exploration of Clinical Factors after Pituitary Adenoma Surgery: A Systematic Review and Meta-Analysis based on Computer Artificial Intelligence System

Background

The first-line treatment for patients with any type of pituitary adenoma is trans-sphenoidal surgery. Considering the prevalence of the condition globally, the treatment is quite common. The recurrence of pituitary adenoma is a recognized occurrence in the medical field; however, there is limited comprehensive research and analysis of the predictive factors of recurrence rates and the clinical factors impacting relapse rates. Identifying the recurrence rates of pituitary adenomas and the clinical factors associated with them could help increase the remission rate by increasing focus on the specific aspects for early diagnosis and improved treatment.

Objective

The objective of the current systematic review and meta-analysis is to assess the recurrent rates based on previous studies and to explore the clinical factors after pituitary surgery.

Methods

A search was performed on PubMed, APA PsycINFO, Scopus, CENTRAL, and Google Scholar databases for English articles published from 1^st January 2010 to 1^st August 2022. Systematic reviews, meta-analysis, evidence syntheses, editorials, commentaries, preclinical studies, abstracts, theses, and preprints were excluded. Meta XL statistical software was used to conduct a prevalence meta-analysis.

Results

PubMed, PsycINFO, and Medline databases were searched. All of the articles were written between 2012 and 2022. In the beginning, 612 items were recognized. After removing duplicates and analyzing the remaining articles in terms of inclusion and exclusion criteria, 31 articles remained.

Conclusion

There is a relationship between recurrence rates and the follow-up period. There were conflicting results about the clinical factors after pituitary adenoma surgery, specifically age and tumor size. Some included studies that there was an association between macroadenomas and high recurrence rates. No study reported that gender was a clinical factor affecting pituitary adenoma surgery outcomes or the recurrence rate. Studies also reported that there was a correlation between the remnant tumor factor and the recurrence rates; adenoma remnants after surgery increased the risk of recurrence rates for patients.

Prognostic Factors for Recurrence in Pituitary Adenomas: Recent Progress and Future Directions

Pituitary adenomas (PAs) are benign lesions; nonetheless, some PAs exhibit aggressive behaviors, which lead to recurrence. The impact of pituitary dysfunction, invasion-related risks, and other complications considerably affect the quality of life of patients with recurrent PAs. Reliable prognostic factors are needed for recurrent PAs but require confirmation. This review summarizes research progress on two aspects—namely, the clinical and biological factors (biomarkers) for recurrent PAs. Postoperative residue, age, immunohistological subtypes, invasion, tumor size, hormone levels, and postoperative radiotherapy can predict the risk of recurrence in patients with PAs. Additionally, biomarkers such as Ki-67, p53, cadherin, pituitary tumor transforming gene, matrix metalloproteinase-9, epidermal growth factor receptor, fascin actin-bundling protein 1, cyclooxygenase-2, and some miRNAs and lncRNAs may be utilized as valuable tools for predicting PA recurrence. As no single marker can independently predict PA recurrence, we introduce an array of comprehensive models and grading methods, including multiple prognostic factors, to predict the prognosis of PAs, which have shown good effectiveness and would be beneficial for predicting PA recurrence.

Multi-Omics Investigations Revealed Underlying Molecular Mechanisms Associated With Tumor Stiffness and Identified Sunitinib as a Potential Therapy for Reducing Stiffness in Pituitary Adenomas

Purpose: Pituitary adenomas (PAs) are the second most common intracranial neoplasms. Total surgical resection was extremely important for curing PAs, whereas tumor stiffness has gradually become the most critical factor affecting the resection rate in PAs. We aimed to investigate the molecular mechanisms of tumor stiffening and explore novel medications to reduce stiffness for improving surgical remission rates in PA patients.

Methods: RNA sequencing, whole-genome bisulfite sequencing, and whole exome sequencing were applied to identify transcriptomic, epigenomic, and genomic underpinnings among 11 soft and 11 stiff PA samples surgically resected from patients at Peking Union Medical College Hospital (PUMCH). GH3 cell line and xenograft PA model was used to demonstrate therapeutic effect of sunitinib, and atomic force microscopy (AFM) was used to detect the stiffness of tumors.

Results: Tumor microenvironment analyses and immunofluorescence staining indicated endothelial cells (ECs) and cancer-associated fibroblasts (CAFs) were more abundant in stiff PAs. Weighted gene coexpression network analysis identified the most critical stiffness-related gene (SRG) module, which was highly correlated with stiff phenotype, ECs and CAFs. Functional annotations suggested SRGs might regulate PA stiffness by regulating the development, differentiation, and apoptosis of ECs and CAFs and related molecular pathways. Aberrant DNA methylation and m6A RNA modifications were investigated to play crucial roles in regulating PA stiffness. Somatic mutation analysis revealed increased intratumoral heterogeneity and decreased response to immunotherapy in stiff tumors. Connectivity Map analysis of SRGs and pRRophetic algorithm based on drug sensitivity data of cancer cell lines finally determine sunitinib as a promising agent targeting stiff tumors. Sunitinib inhibited PA growth in vitro and in vivo, and also reduced tumor stiffness in xenograft PA models detected by AFM.

Conclusion: This is the first study investigating the underlying mechanisms contributing to the stiffening of PAs, and providing novel insights into medication therapy for stiff PAs.

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.

Solid tumor size for prediction of recurrence in large and giant non-functioning pituitary adenomas

A subset of large non-functioning pituitary adenomas (lNFPA) and giant non-functioning pituitary adenomas (gNFPA) undergoes early progression/recurrence (P/R) after surgery. This study revealed the clinical and image predictors of P/R in lNFPA and gNFPA, with emphasis on solid tumor size. This retrospective study investigated the preoperative MR imaging features for the prediction of P/R in lNFPA (> 3 cm) and gNFPA (> 4 cm). Only the patients with a complete preoperative brain MRI and undergone postoperative MRI follow-ups for more than 1 year were included. From November 2010 to December 2020, a total of 34 patients diagnosed with lNFPA and gNFPA were included (median follow-up time 47.6 months) in this study. A total of twenty-three (23/34, 67.6%) patients had P/R, and the median time to P/R is 25.2 months. Solid tumor diameter (STD), solid tumor volume (STV), and extent of resection are associated with P/R (p < 0.05). Multivariate analysis showed large STV is a risk factor for P/R (p < 0.05) with a hazard ratio of 30.79. The cutoff points of STD and STV for prediction of P/R are 26 mm and 7.6 cm³, with AUCs of 0.78 and 0.79 respectively. Kaplan-Meier analysis of tumor P/R trends showed that patients with larger STD and STV exhibited shorter progression-free survival (p < 0.05). For lNFPA and gNFPA, preoperative STD and STV are significant predictors of P/R. The results offer objective and valuable information for treatment planning in this subgroup.

Towards precision medicine for clinically non-functioning pituitary tumours

OBJECTIVE

Clinically non-functioning pituitary tumours (NFPT) are a heterogenous group of neoplasms with diverse outcomes. The purpose of this narrative review was to summarize available data on predictive factors, both in routine practice and research settings.

DESIGN

A literature review was conducted for papers published in peer-reviewed journals, investigating clinical, radiological, pathological and genetic predictive factors in NFPT.

RESULTS

Several clinical and radiological factors have been associated with NFPT recurrence and/or aggressiveness, including larger size and pre-/post-operative growth rates. Application of transcription factor immunohistochemistry has given rise to improved subtype identification, including 'higher-risk' subtypes, in routine clinical practice. Numerous other pathological and genetic biomarkers have demonstrated promise for prognostication in the research setting.

CONCLUSION

NFPT are a heterogenous group of tumours, characterized by diverse presentation, pathogenesis and outcomes. Ongoing refinements in understanding of tumour biology are likely to pave the way to improved integrative prognostication and precision medicine for NFPT.

Non-functioning pituitary macroadenomas: factors affecting postoperative recurrence, and pre- and post-surgical endocrine and visual function

BACKGROUND

Non-functioning pituitary macroadenomas (NFPAs) with visual field defects are ideally managed by transsphenoidal tumour resection to improve vision, and long-term postsurgical follow up is necessary to monitor for tumour recurrence. Regular updates from global data are necessary for developing optimal management strategies of these tumours.

METHODS

Pre- and postoperative visual and endocrine profile, imaging characteristics and details of surgical interventions among patients with NFPAs managed between 2008 and 2019 in a UK regional centre were assessed. The radiological and surgical outcomes including postoperative complications, recurrence risk and the factors influencing outcomes also were assessed.

RESULTS

105 cases with mean (SD) age 60.1 (14.3) years and follow-up duration 60 (37) months were studied. 67 (64%) patients were male. Five-year recurrence-free survival rate was 71.5% (95% confidence interval [CI] 62.7% to 81.6%) with 33 (31%) tumour recurrences of whom 20 (60%) received radiotherapy and 9 (27%) underwent further surgery. Younger age, tumour volume, and bilateral cavernous sinus extension were the predictors of recurrence on univariate analysis, while younger age was the only factor on multivariate analysis (Hazard ratio 0.95; 95% CI: 0.92, 0.97). 72/78 patients (92%) with preoperative visual field defects improved after surgery, of whom 27 (35%) had full recovery. 20 (24%) patients had recovery of an abnormal hormone axis. 15 patients (16%) developed perioperative complications such as cerebrospinal fluid leak (12 cases), meningitis (2 cases), and bleeding (2 cases).

CONCLUSIONS

Five-year recurrence-free survival after transsphenoidal resection for NFPAs was 71.5% with older age at surgery conferring lower risk of recurrence. Visual recovery/ improvement occurred in 92% of cases with preoperative visual defects following surgery.

Post-operative volumes following endoscopic surgery for non-functioning pituitary macroadenomas are predictive of further intervention, but not endocrine outcomes

BACKGROUND

Transsphenoidal surgery (TSS) remains the treatment of choice for non-functioning pituitary macroadenomas (NFPMA). The value of measuring tumour volumes before and after surgery, and its influence on endocrine outcomes and further treatment of the residual or recurrent tumour are unknown.

METHODS

Data from patients who underwent endoscopic TSS for a NFPMA (2009-2018) in a UK tertiary centre were analysed for pre- and post-operative endocrine and surgical outcomes.

RESULTS

Of 173 patients with NFPMA, 159 (61% male) were treatment naïve. At presentation, 76.2% (77/101) had ≥1 pituitary axis deficit. Older age (p = 0.002) was an independent predictor for multiple hormonal deficiencies. Preoperative tumour volume did not correlate with degree of hypopituitarism. Postoperative tumour volume and extent of tumour resection were not predictive of new onset hypopituitarism. Hormonal recovery was observed in 16 patients (20.8%) with impaired pituitary function, with the greatest recovery in the hypothalamic-pituitary-adrenal axis (21.2%, 7/33). A larger residual tumour volume was predictive of adjuvant radiotherapy (3.40 vs. 1.24 cm³, p = 0.005) and likelihood for repeat surgery (5.40 vs. 1.67cm³, p = 0.004).

CONCLUSION

Pre- and post-operative NFPMA volumes fail to predict the number of pituitary hormone deficits, however, greater post-operative residual volumes increase the likelihood of further intervention to control tumour growth.

Guidelines in the management of CNS tumors

INTRODUCTION

Evidence-based, clinical practice guidelines in the management of central nervous system tumors (CNS) continue to be developed and updated through the work of the Joint Section on Tumors of the Congress of Neurological Surgeons (CNS) and the American Association of Neurological Surgeons (AANS).

METHODS

The guidelines are created using the most current and clinically relevant evidence using systematic methodologies, which classify available data and provide recommendations for clinical practice.

CONCLUSION

This update summarizes the Tumor Section Guidelines developed over the last five years for non-functioning pituitary adenomas, low grade gliomas, vestibular schwannomas, and metastatic brain tumors.

Nomogram predictive model of post-operative recurrence in non-functioning pituitary adenoma

Background

To analyze and predict the possibility of post-operative recurrence in non-functioning pituitary adenoma (NFPA) patients, we investigated the clinical factors leading to tumor recurrence and built a nomogram predictive model based on these risk factors.

Methods

A single-center retrospective study was performed. A total of 145 NFPA patients who underwent surgical treatment at Shenzhen People's Hospital from September 2013 to January 2019 were selected. Among them, 52 patients were diagnosed with recurrence of NFPA according to follow-up investigations. Binary logistic regression analysis was used to determine the significant risk factors. A nomogram model was then built to predict recurrence using these factors.

Results

The univariate analysis and the binary logistic regression analysis showed that age, tumor size, cavernous invasion, sphenoid sinus invasion, and surgical extension were significant factors affecting tumor recurrence. We then built a nomogram model to predict post-operative recurrence in NFPA patients using these factors. The correlation analysis indicated that sphenoid sinus invasion [hazard ratio (HR) =13.14, 95% confidence interval (CI): 7.03-24.58, P<0.0001], cavernous sinus invasion (HR =7.53, 95% CI: 4.27-13.28, P<0.0001), and tumor size (HR =11.06, 95% CI: 6.11-20.03, P<0.0001) could promote the recurrence of NFPA. In contrast, advanced age (HR =0.50, 95% CI: 0.28-0.86, P<0.0001) and gross total resection (HR =0.12, 95% CI: 0.07-0.22, P<0.0001) could effectively inhibit recurrence.

Conclusions

In this study, we developed a nomogram predictive model based on the significant recurrence-associated factors for NFPA. This nomogram may aid neurosurgeons in the post-operative prediction of recurrence, and may facilitate tailored counseling of individual patients.

World Health Ozganization 2017 Classification of Pituitary Tumors

The 2017 (fourth edition) World Health Organization Classification of Endocrine Tumors has recommended major changes in classification of tumors of the pituitary gland and region. In addition to the accurate tumor subtyping, assessment of the tumor proliferative potential (mitotic and/or Ki-67 index) and other clinical parameters such as tumor invasion is strongly recommended in individual cases for consideration of clinically aggressive adenomas. It is expected that this new WHO classification will establish more uniform biologically and clinically groups of pituitary tumors and contribute to understanding of clinical outcomes for patients harboring pituitary tumors.

TBR-760, a Dopamine-Somatostatin Compound, Arrests Growth of Aggressive Nonfunctioning Pituitary Adenomas in Mice

TBR-760 (formerly BIM-23A760) is a chimeric dopamine (DA)-somatostatin (SST) compound with potent agonist activity at both DA type 2 (D2R) and SST type 2 (SSTR2) receptors. Studies have shown that chimeric DA-SST compounds are more efficacious than individual DA and/or SST analogues, either alone or combined, in inhibiting secretion from primary cultures of human somatotroph and lactotroph tumor cells. Nonfunctioning pituitary adenomas (NFPAs) express both D2R and SSTR2 and, consequently, may respond to TBR-760. We used a mouse model with the pro-opiomelanocortin (POMC) gene knocked out that spontaneously develops aggressive NFPAs. Genomic microarray and DA and SST receptor messenger RNA expression analysis indicate that POMC KO mouse tumors and human NFPAs have similar expression profiles, despite arising from different cell lineages, establishing POMC KO mice as a model for study of NFPAs. Treatment with TBR-760 for 8 weeks resulted in nearly complete inhibition of established tumor growth, whereas tumors from vehicle-treated mice increased in size by 890 ± 0.7%. Comparing TBR-760 with its individual DA and SST components, TBR-760 arrested tumor growth. Treatment with equimolar or 10×-higher doses of the individual SST or DA agonists, either alone or in combination, had no significant effect. One exception was the lower dose of DA agonist that induced modest suppression of tumor growth. Only the chimeric compound TBR-760 arrested tumor growth in this mouse model of NFPA. Further, significant tumor shrinkage was observed in 20% of the mice treated with TBR-760. These results support the development of TBR-760 as a therapy for patients with NFPA.

Acute Unilateral Oculomotor Nerve Palsy as the Initial Presenting Sign of Nonfunctioning Apoplectic Gonadotroph Adenoma

Pituitary macroadenoma usually presents with visual field defects. Oculomotor nerve palsy is a rare presentation, and usually a sign of para-sellar growth and cavernous sinus extension. The oculomotor nerve is more susceptible to laterally transmitted pressure by pituitary mass expansion because of its anatomical location. A slow onset oculomotor nerve palsy results from either gradual compression of the nerve in the sinus wall or direct infiltration of the nerve by the pituitary tumor. We are reporting a unique case of a 68-year-old African American patient who presented to an ophthalmology clinic with left eye complete ptosis, blurry vision, and a progressive headache for a few weeks. He was found to have a nonfunctioning pituitary adenoma (NFPA) that required urgent transnasal transsphenoidal tumor resection. The patient's ocular movements significantly improved a few days postoperatively, and repeated computed tomography (CT) of the head showed complete resection of the pituitary adenoma. The postoperative morning cortisol level was significantly low, confirming the diagnosis of secondary adrenal insufficiency. The patient was treated with corticosteroid replacement therapy.

Current perspectives on recurrent pituitary adenoma: The role and timing of surgery vs adjuvant treatment

The clinical course of pituitary adenoma can be highly variable. Aggressive pituitary tumours may require multimodal therapy with multiple operations. Even standard pituitary adenomas exhibit relatively high long-term recurrence rates and delayed intervention is often required. The indications for revision surgery in the endoscopic era are expanding for both functioning and nonfunctioning tumours, including access to the cavernous sinus and intracranial compartments. Although revision surgery can be challenging, it has been demonstrated to be both safe and effective. The question of the use of early radiotherapy in pituitary adenoma remains controversial. Our increasing understanding of pituitary tumour biology facilitates individualized treatment and surveillance protocols, with early intervention in high-risk adenoma subtypes. In this review, we discuss the treatment options for recurring pituitary tumours and focus on the role of revision surgery.

Genetic and Epigenetic Causes of Pituitary Adenomas

Pituitary adenomas (PAs) can be classified as non-secreting adenomas, somatotroph adenomas, corticotroph adenomas, lactotroph adenomas, and thyrotroph adenomas. Substantial advances have been made in our knowledge of the pathobiology of PAs. To obtain a comprehensive understanding of the molecular biological characteristics of different types of PAs, we reviewed the important advances that have been made involving genetic and epigenetic variation, comprising genetic mutations, chromosome number variations, DNA methylation, microRNA regulation, and transcription factor regulation. Classical tumor predisposition syndromes include multiple endocrine neoplasia type 1 (MEN1) and type 4 (MEN4) syndromes, Carney complex, and X-LAG syndromes. PAs have also been described in association with succinate dehydrogenase-related familial PA, neurofibromatosis type 1, and von Hippel-Lindau, DICER1, and Lynch syndromes. Patients with aryl hydrocarbon receptor-interacting protein (AIP) mutations often present with pituitary gigantism, either in familial or sporadic adenomas. In contrast, guanine nucleotide-binding protein G(s) subunit alpha (GNAS) and G protein-coupled receptor 101 (GPR101) mutations can lead to excess growth hormone. Moreover, the deubiquitinase gene USP8, USP48, and BRAF mutations are associated with adrenocorticotropic hormone production. In this review, we describe the genetic and epigenetic landscape of PAs and summarize novel insights into the regulation of pituitary tumorigenesis.

Non-functioning pituitary adenomas: indications for pituitary surgery and post-surgical management

PURPOSE

Non-functioning pituitary adenomas (NFPAs) are associated with impaired well-being, increased comorbidities, and reduced long-term survival. Data on optimal management of NFPAs around surgical treatment are scarce, and postoperative treatment and follow-up strategies have not been evaluated in prospective trials. Here, we review the preoperative, perioperative, and early postoperative management of patients with NFPAs.

METHODS

We searched Medline and the Cochrane Library for articles published in English with the following items "Pituitary neoplasms AND Surgery" and "Surgery AND Hypopituitarism". Studies containing detailed analyses of the management of NFPAs in adult patients, including pituitary surgery, endocrine care, imaging, ophthalmologic assessment and long-term outcome were reviewed.

RESULTS

Treatment options for NFPAs include active surveillance, surgical resection, and radiotherapy. Pituitary surgery is currently recommended as first-line treatment in patients with visual impairment due to adenomas compressing the optic nerves or chiasma. Radiotherapy is reserved for large tumor remnants or tumor recurrence following one or more surgical attempts. There is no consensus of optimal pre-, peri-, and postoperative management such as timing, frequency, and duration of endocrine, radiologic, and ophthalmologic assessments as well as management of smaller tumor remnants or tumor recurrence.

CONCLUSIONS

In clinical practice, there is a great variation in the treatment and follow-up of patients with NFPAs. We have, based on available data, suggested an optimal management strategy for patients with NFPAs in relation to pituitary surgery. Prospective trials oriented at drawing up strategies for the management of NFPAs are needed.

Residual Tumor Confers a 10-Fold Increased Risk of Regrowth in Clinically Nonfunctioning Pituitary Tumors

Objective

We evaluated tumor recurrence and regrowth rates following endoscopic transnasal transsphenoidal (TNTS) surgical removal in a consecutive series of clinically nonfunctioning pituitary adenomas (CNFTs).

Design

Retrospective chart review of clinical, biochemical, and sellar MRI findings in all TNTS surgeries in patients with CNFT, performed by a single surgeon, between 2008 and 2015 (n = 280).

Patients

Ninety-three patients met eligibility criteria, with complete clinical, biochemical, and imaging follow-up for a 3-year minimum.

Results

Of 85 patients who were not irradiated, 3-month postsurgical MRI demonstrated no residual tumor in 58 of 85 (68.2%), equivocal findings in 12 of 85 (14.1%), and definite residual tumor in 15 of 85 (17.6%) patients. Six of 85 (7.1%) demonstrated tumor regrowth by 3 years, and 2 further patients demonstrated true tumor recurrence at 3 and 6 years after surgery, respectively, for a total recurrence rate of 9.4% (8 of 85). Eight of the 93 patients were irradiated between 3 months and 4 years after pituitary surgery. In 3 patients with tumor regrowth, 2 exhibited residual tumor and 1 had no residual findings at the 3-month postoperative imaging. Overall, Ki-67 labeling index or Knosp grading did not predict recurrence.

Conclusion

Tumor recurrence at 3 years was low (1 of 58; 1.7%) if the 3-month postoperative MRI showed no residual tumor. The findings support a less frequent imaging schedule for this group. Patients with definite residual tumor visible at 3 months harbor the greatest risk for tumor growth, but regrowth does not occur in all patients (6 of 15; 40%).

Comparison of Radiographic Approaches to Assess Treatment Response in Pituitary Adenomas: Is RECIST or RANO Good Enough?

Context

Pituitary adenomas (PA) are often irregularly shaped, particularly posttreatment. There are no standardized radiographic criteria for assessing treatment response, substantially complicating interpretation of prospective outcome data. Existing imaging frameworks for intracranial tumors assume perfectly spherical targets and may be suboptimal.

Objective

To compare a three-dimensional (3D) volumetric approach against accepted surrogate measurements to assess PA posttreatment response (PTR).

Design

Retrospective review of patients with available pre- and postradiotherapy (RT) imaging. A neuroradiologist determined tumor sizes in one dimensional (1D) per Response Evaluation in Solid Tumors (RECIST) criteria, two dimensional (2D) per Response Assessment in Neuro-Oncology (RANO) criteria, and 3D estimates assuming a perfect sphere or perfect ellipsoid. Each tumor was manually segmented for 3D volumetric measurements. The Hakon Wadell method was used to calculate sphericity.

Setting

Tertiary cancer center.

Patients or Other Participants

Patients (n = 34, median age = 50 years; 50% male) with PA and MRI scans before and after sellar RT.

Interventions

Patients received sellar RT for intact or surgically resected lesions.

Main Outcome Measures

Radiographic PTR, defined as percent tumor size change.

Results

Using 3D volumetrics, mean sphericity = 0.63 pre-RT and 0.60 post-RT. With all approaches, most patients had stable disease on post-RT scan. PTR for 1D, 2D, and 3D spherical measurements were moderately well correlated with 3D volumetrics (e.g., for 1D: 0.66, P < 0.0001) and were superior to 3D ellipsoid. Intraclass correlation coefficient demonstrated moderate to good reliability for 1D, 2D, and 3D sphere (P < 0.001); 3D ellipsoid was inferior (P = 0.009). 3D volumetrics identified more potential partially responding and progressive lesions.

Conclusions

Although PAs are irregularly shaped, 1D and 2D approaches are adequately correlated with volumetric assessment.

Perioperative multidisciplinary management of endoscopic transsphenoidal surgery for sellar lesions: practical suggestions from the Padova model

Perioperative management of patients with sellar lesion submitted to endoscopic transsphenoidal neurosurgery (TSS) lacks standardization and therefore it is committed to each center clinical practice. Although neurosurgical procedure remains the same for all sellar lesions, perioperative approach can require different measures depending on the underlying disease. With the aim of standardizing our perioperative procedures and sharing our experience with other centers involved in the management of pituitary disease, we developed a clinical care path for patients with sellar lesions candidate to endoscopic TSS. For the drafting of the following protocol, the national and international guidelines published in the last 5 years have been evaluated and integrated with our center experience accumulated in decades of clinical practice. A steering committee including medical doctors involved in management of patients with pituitary masses at the Padua Hospital reviewed current knowledge on this topic. The committee developed a first draft which was shared with a broader group of medical doctors to reach a preliminary consensus; when it was reached, the clinical care assistance pathway was confirmed, validated, and published in the local web-based health service. We want to present and share our experience with colleagues involved in the perioperative management of pituitary diseases in other centers.

Growth of Pituitary Macroadenomas Postpartial Resection: Implications for Adjuvant Radiotherapy

Objective  To determine the volumetric growth in macroadenomas (MAs) patients with residual postoperative disease and to identify subpopulations with rapid postoperative growth rate that may benefit from early salvage radiotherapy (RT). Methods  Patients who had undergone a partial resection for MAs and did not receive immediate postoperative RT were eligible. Residual tissue was contoured on serial magnetic resonance imaging and planimetric and volumetric changes in size were measured. Growth rates were established by a single observer using serial volumetric measurements. Data were analyzed to find a relationship among growth rate, adjuvant treatment, and patient and tumor characteristics. Results  Thirty-one patients met the eligibility criteria. Nine patients (29%) required adjuvant treatment because of tumor growth. Volumetric growth was identified 95% of the time compared with 64% planimetrically. Planimetric growth could not be established in 10% of patients showing volumetric changes. Median growth rate was 0.4464 mL/y. Growth rate positively correlated with size of residual postoperative volume ( p  < 0.001). Receiving salvage treatment positively correlated with growth rate ( p  = 0.001), particularly at a rate above 2.19 mL/y ( p  = 0.0064). Five patients (16%) had a growth rate above this level, all of which required salvage treatment. Patients with postoperative residual volume > 3.95 mL were most likely to experience rapid growth rate and require salvage treatment ( p  = 0.007). Conclusion  Volumetric measurement was found to be superior to planimetric measurement in detecting changes in patients with residual tumors. Patients with postoperative residual volume > 3.95 mL should be considered for early treatment with RT.

Medical therapy for non-functioning pituitary tumors-a critical approach

Non-functioning pituitary adenomas (NFPAs) are the second most common variant of pituitary tumors. When symptomatic, primary therapy is surgery. Recurrence rates are high. Since many NFPAs express dopamine and somatostatin receptors, medical therapy has been used after surgery in order to prevent recurrence. So far, dopamine agonists have been more widely tested with some promise when introduced immediately after surgery but with less efficacy when introduced later upon tumor regrowth. Currently, the role of medical therapy to prevent tumor regrowth in NFPAs is limited by imprecisions as to final outcome and uncertainties concerning on patient selection, dosing, duration, and side effects.

Long-term follow-up of a large prospective cohort of patients with nonfunctioning pituitary adenomas: The outcome of a conservative management policy

OBJECTIVE

To assess the clinical outcome of a strategy of conservative monitoring of patients with nonfunctioning pituitary adenomas (NFPA) after pituitary surgery and in patients without surgery.

DESIGN

Retrospective study of outcomes, using a clinical information system.

PATIENTS

An unselected, clinical series of patients seen in a single centre between 1989 and 2015.

MEASUREMENTS

Review of clinical information system data to obtain details and dates of surgery, radiotherapy, pituitary imaging and outcomes.

RESULTS

We identified 190 cases of NFPA. Trans-sphenoidal surgery (TSS) had been performed as primary therapy in 132 cases (all macro-adenomas). At a mean 7.6-years follow-up after TSS without immediate pituitary radiotherapy, recurrence occurred in 10.7% of cases with no visible postoperative residual adenoma, 38.8% with intrasellar and 66.7% with extrasellar residuum. Recurrence was defined as growth of residual tumour requiring intervention. On survival analysis, at 10 years, recurrence-free survival was 75% in patients with no residual tumour and 40% with intrasellar residuum. Recurrence occurred in 12.5% of 24 patients who had received postop radiotherapy. Patients were monitored conservatively without initial surgery in 65 patients. After a mean of 5-year monitoring, only 20% required intervention during follow-up (18.5% TSS) and 30.8% died of nonpituitary causes during follow-up.

CONCLUSION

This study suggests that a conservative approach may be safe and appropriate in patients with NFPA if followed up with appropriate imaging surveillance, whether postoperative or without primary surgery.

Post-operative imaging assessment of non-functioning pituitary adenomas

BACKGROUND

Non-functioning pituitary adenomas (NFAs) are the most common pituitary tumors. There is significant variability in clinical practice in terms of post-operative imaging evaluation. The objective of this manuscript is to provide an exhaustive review of published articles pertaining to the post-operative imaging evaluation of NFAs.

METHODS

The MEDLINE database was queried for studies investigating imaging for the post-operative evaluation of pituitary adenomas. From an initial search of 5589 articles, 37 articles were evaluated in detail and included in this review.

RESULTS

Magnetic resonance imaging (MRI) is the gold standard for post-operative monitoring of NFAs, although functional imaging modalities may improve identification of residual tumor in conjunction with MRI. The residual tumor can be distinguished from post-operative changes by experienced practitioners using high-resolution MRI in the immediate post-operative setting (within 1 week of surgery). However, continued imaging evolution in the appearance of residual tumor or resection cavity is expected up to 3 months post-operatively.

CONCLUSIONS

Post-operative imaging appearance of the pituitary gland, optic apparatus, and pneumocephalus patterns, correlated with the clinical outcomes. Long-term, lifetime follow-up is warranted for NFA patients who underwent surgical resection.

A comparative, population-based analysis of pituitary incidentalomas vs clinically manifesting sellar masses

PURPOSE

Sellar masses may present either with clinical manifestations of mass effect/hormonal dysfunction (CMSM) or incidentally on imaging (pituitary incidentaloma (PI)). This novel population-based study compares these two entities.

METHODS

Retrospective analysis of all patients within a provincial pituitary registry between January 2006 and June 2014.

RESULTS

Nine hundred and three patients were included (681 CMSM, 222 PI). CMSM mainly presented with secondary hormone deficiencies (SHDs) or stalk compression (29.7%), whereas PIs were found in association with neurological complaints (34.2%) (P < 0.0001). PIs were more likely to be macroadenomas (70.7 vs 49.9%; P < 0.0001). The commonest pathologies among CMSM were prolactinomas (39.8%) and non-functioning adenomas (NFAs) (50%) in PI (P < 0.0001). SHDs were present in 41.3% CMSM and 31.1% PI patients (P < 0.0001) and visual field deficit in 24.2 and 29.3%, respectively (P = 0.16). CMSM were more likely to require surgery (62.9%) than PI (35.8%) (P < 0.0005). The commonest surgical indications were impaired vision and radiological evidence of optic nerve compression. Over a follow-up period of 5.7 years for CMSM and 5.0 years for PI, tumour growth/recurrence occurred in 7.8% of surgically treated CMSM and 2.6% without surgery and PI, 0 and 4.9%, respectively (P = 1.0). There were no significant differences in the risk of new-onset SHD in CMSM vs PI in those who underwent surgery (P = 0.7) and those who were followed without surgery (P = 0.58).

CONCLUSIONS

This novel study compares the long-term trends of PI with CMSM, highlighting the need for comprehensive baseline and long-term radiological and hormonal evaluations in both entities.

Histopathological classification of non-functioning pituitary neuroendocrine tumors

Non-functioning pituitary neuroendocrine tumors do not cause endocrine symptoms related to hypersecretion of adenohypophyseal hormones and are clinically characterized by symptoms due to growing sellar tumor mass. Histopathological classification of this tumor group has always been challenging due to their heterogeneity, limited knowledge on their biology, and diverse methodological problems. We have searched PubMed database for data related to the histopathological classification of non-functioning pituitary tumors and methods for its application. Principles of the classification and grading presented in the recently released 4th edition of the World Health Organization classification of endocrine tumors have been summarized. Based on the expression of anterior pituitary hormones and pituitary specific transcription factors, gonadotroph tumors dominate within the group of clinically non-functioning tumors, followed by corticotroph type; however, other less common types of the non-functioning tumors can be identified. Assessment of tumor cell proliferation is important to identify "high-risk adenomas." A few subtypes of non-functioning tumors belong to the category of potentially aggressive tumors, independent of the cell proliferation rate. Here, we present up to date criteria for the classification of clinically non-functioning pituitary tumors, offer a diagnostic approach for the routine clinical use, and emphasize a need for inclusion of prognostic and predictive markers in the classification.

Prognostic factors of regrowth in nonfunctioning pituitary tumors

Surgery is the treatment of choice for nonfunctioning pituitary tumors (NFPTs). Postoperative tumor regrowth during follow-up is present in about half of the patients with invasive NFPTs with residual tumor but occurs also in 15% of patient without residue. Therapeutic strategies should consider this risk of recurrence and the potential side effects associated with therapeutic options. Identification of prognostic markers is mandatory to help clinicians to predict the risk of recurrence and to choose the best strategy between conservative follow-up, second surgery, postoperative adjuvant radiation therapy, and medical treatment (dopamine agonists, somatostatin analogs). Recent advances in pathological classification may be the first step for identification of NFPTs with a high risk of recurrence.

Predictors for secondary therapy after surgical resection of nonfunctioning pituitary adenomas

OBJECTIVE

Factors determining recurrence of nonfunctioning pituitary adenomas (NFAs) that require further therapy are unclear as are postoperative follow-up imaging guidelines. We aimed to identify predictors for secondary therapy after surgical resection of NFAs and use this knowledge to inform postoperative management.

DESIGN AND PATIENTS

A single-centre retrospective study of surgically resected NFAs in 108 patients followed for up to 15 years. Serial tumour images were analysed for size, location and growth rate (GR) and tissue analysed for hormone cell type and proliferation indices with secondary treatment as outcome measure.

RESULTS

Twenty-four of 66 (36%) patients harbouring a postoperative remnant required secondary treatment, all occurring within 10 years. No secondary treatment was required in any of 42 patients with complete tumour resection. Age, gender, remnant volume and tumour histology were not different between patients requiring and not requiring secondary therapy. Remnant GRs in those requiring secondary therapy were more than 10-fold higher (P<.01). Tumours with a GR ≥80 mm³ /y (Hazard Ratio[HR]: 8.1, Confidence Interval [CI]: 2.4-27.3,P<.01) and those located in the suprasellar region (HR: 6.1, CI: 1.1-32, P=.03) had a higher risk for secondary therapy. Tumour GR in the first three postoperative years correlated significantly (r² =.6, P<.01) with GR during the period of follow-up.

CONCLUSION

In surgically resected NFAs further treatment is dependent on the presence of residual tumour, growth rate and location but not tumour histology. Postoperative growth rate of NFAs in the first 3 years of imaging can be used to tailor long-term follow-up to optimize use of health resources.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guideline on Posttreatment Follow-up Evaluation of Patients With Nonfunctioning Pituitary Adenomas

BACKGROUND

Nonfunctioning pituitary adenomas (NFPAs) are the most frequent pituitary tumors. Due to the lack of hormonal hypersecretion, posttreatment follow-up evaluation of NFPAs is challenging.

OBJECTIVE

To create evidence-based guidelines in an attempt to formulate guidance for posttreatment follow-up in a consistent, rigorous, and cost-effective way.

METHODS

An extensive literature search was performed. Only clinical articles describing postoperative follow-up of adult patients with NFPAs were included. To ascertain the class of evidence for the posttreatment follow-ups, the authors used the Clinical Assessment evidence-based classification.

RESULTS

Twenty-three studies met the inclusion criteria with respect to answering the questions on the posttreatment radiologic, endocrinologic, and ophthalmologic follow-up. Through this search, the authors formulated evidence-based guidelines for radiologic, endocrinologic, and ophthalmologic follow-up after surgical and/or radiation treatment.

CONCLUSION

Long-term radiologic, endocrinologic, and ophthalmologic surveillance monitoring after surgical and/or radiation therapy treatment of NFPAs to evaluate for tumor recurrence or regrowth, as well as pituitary and visual status, is recommended. There is insufficient evidence to make a recommendation on the duration of time of surveillance and its frequency. It is recommended that the first radiologic study to evaluate the extent of resection of the NFPA be performed ≥3 months after surgical intervention. The full guidelines document for this chapter can be located at https://www.cns.org/guidelines/guidelines-management-patients-non-functioning-pituitary-adenomas/Chapter_8.

ABBREVIATION

NFPA, nonfunctioning pituitary adenoma.

Younger age is a risk factor for regrowth and recurrence of nonfunctioning pituitary macroadenomas: Results from a single Australian centre

OBJECTIVE

The natural history of nonfunctioning pituitary macroadenomas (NFPMA) after surgical resection is variable, with guidelines unable to define the duration of radiological follow-up. In this first Australian series, we identify risk factors for regrowth/recurrence of NFPMA to assist with guiding recommendations for long-term follow-up.

DESIGN

Retrospective analysis of all radiotherapy-naïve cases with NFPMA resected between 1995 and 2013.

PATIENTS

One hundred and twenty-three cases had both ≥2 postoperative scans and ≥12-month follow-up.

MEASUREMENTS

Regrowth was defined as any sustained increase in diameter of residual adenoma or recurrence as any new adenoma occurring post complete resection on serial pituitary MRI.

RESULTS

Median follow-up time was 48 months (interquartile range [IQR]: 31-86). Overall regrowth/recurrence occurred in 29% (36/123). Regrowth occurred in 40% (30/76) at a median time of 44.5 months (IQR 22-80) compared to recurrence of 12.5% (6/48; P=.003), occurring at a median time of 48 months (IQR 12-96; P=.7). Further treatment was required in 66.7% and 56.7%, respectively (=1.0). Risk factors for regrowth/recurrence by multivariate analysis were presence of residual disease and younger age at presentation. The longest time for regrowth was 168 months (14 years) and recurrence 156 months (13 years).

CONCLUSIONS

Presence of postoperative residual adenoma and younger age at presentation are the main predictors of regrowth/recurrence in NFPMA. Long-term serial imaging is required to detect regrowth and recurrence in younger patients and those with residual disease. Most regrowth/recurrences will occur within 10 years of follow-up.

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.

Clinically non-functioning pituitary adenomas: Pathogenic, diagnostic and therapeutic aspects

Clinically non-functioning pituitary adenomas (NFPAs) are among the most common tumors in the sellar region. These lesions do not cause a hormonal hypersecretion syndrome, and are therefore found incidentally (particularly microadenomas) or diagnosed based on compressive symptoms such as headache and visual field defects, as well as clinical signs of pituitary hormone deficiencies. Immunohistochemically, more than 45% of these adenomas stain for gonadotropins or their subunits and are therefore called gonadotropinomas, while 30% of them show no immunostaining for any hormone and are known as null cell adenomas. The diagnostic approach to NFPAs should include visual field examination, an assessment of the integrity of all anterior pituitary hormone systems, and magnetic resonance imaging of the sellar region to define tumor size and extension. The treatment of choice is transsphenoidal resection of the adenoma, which in many instances cannot be completely accomplished. The recurrence rate after surgery may be up to 30%. Persistent or recurrent adenomas are usually treated with radiation therapy. In a small proportion of these cases, drug treatment with dopamine agonists and, to a lesser extent, somatostatin analogs may achieve reduction or at least stabilization of the tumor.

Early postoperative growth in non-functioning pituitary adenomas; A tool to tailor safe follow-up

PURPOSE

Non-functioning pituitary adenomas are common, and the treatment and follow-up of these patients represent a multidisciplinary challenge. First line treatment is transphenoidal surgery, with debulking or total removal of tumour. A substantial portion of the tumours relapse after surgery, and there is no consensus of how to follow these patients postoperatively. Our aim was to characterize the postoperative growth of non-functioning pituitary adenomas and correlate it to clinical and paraclinical data.

METHODS

We retrospectively registered 52 patients operated for non-functioning pituitary adenomas, with four or more consecutive MR-investigations not interrupted by secondary treatment. Adenoma volumes were estimated by the Cavalieri principle with summation of manually drawn areas multiplied by slice interval. Growth curves were modelled and tumour volume doubling time was calculated for 39 tumours with regrowth after surgery.

RESULTS

A total of 13 tumours showed exponential growth, 10 linear growth and 16 logistic growth after surgery. The remaining 13 did not show regrowth of tumour. Seven of the exponential growing tumours underwent secondary surgery, compared to one and two of linear and logistic growing tumours (p = 0.03), respectively. Initial tumour volume doubling time was significantly lower in logistic growing tumours than in exponential growing tumours (p < 0.01). Men had tumours with lower tumour volume doubling time than women (p = 0.03). None of the tumours demonstrated signs of accelerated growth.

CONCLUSION

Residual tumours following surgery frequently grow. The logistic growing tumours had the fastest initial growth in our cohort. We found no indication of accelerated growth, whereby the tumour volume doubling time might be used to predict a "worst-case" scenario when planning follow-up of these patients.

Outcome of Nonfunctioning Pituitary Adenomas That Regrow After Primary Treatment: A Study From Two Large UK Centers

CONTEXT

Despite the major risk of regrowth of clinically nonfunctioning pituitary adenomas (CNFAs) after primary treatment, systematic data on the probability of further tumor progression and the effectiveness of management approaches are lacking.

OBJECTIVE

To assess the probability of further regrowth(s), predictive factors, and outcomes of management approaches in patients with CNFA diagnosed with adenoma regrowth after primary treatment.

PATIENTS, DESIGN, AND SETTING

Retrospective cohort study of 237 patients with regrown CNFA managed in two UK centers.

RESULTS

Median follow-up was 5.9 years (range, 0.4 to 37.7 years). The 5-year second regrowth rate was 35.3% (36.2% after surgery; 12.5% after radiotherapy; 12.7% after surgery combined with radiotherapy; 63.4% with monitoring). Of those managed with monitoring, 34.8% eventually were offered intervention. Type of management and sex were risk factors for second regrowth. Among those with second adenoma regrowth, the 5-year third regrowth rate was 26.4% (24.4% after surgery; 0% after radiotherapy; 0% after surgery combined with radiotherapy; 48.3% with monitoring). Overall, patients with a CNFA regrowth had a 4.4% probability of a third regrowth at 5 years and a 10.0% probability at 10 years; type of management of the first regrowth was the only risk factor. Malignant transformation was diagnosed in two patients.

CONCLUSIONS

Patients with regrown CNFA after primary treatment continue to carry considerable risk of tumor progression, necessitating long-term follow-up. Management approach to the regrowth was the major factor determining this risk; monitoring had >60% risk of progression at 5 years, and a substantial number of patients ultimately required intervention.

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.

Selection and validation of reliable reference genes for RT-qPCR analysis in a large cohort of pituitary adenomas

BACKGROUND

Real-time reverse transcription quantitative PCR (RT-qPCR) has become the method of choice for quantification of gene expression changes. The most important limitations of RT-qPCR are inappropriate data normalization and inconsistent data analyses. Pituitary adenomas are common tumours, and the appropriate interpretation of increasingly published data within this field is prevented by the lack of a proper selection and validation of stably expressed reference genes.

AIM

To find and validate the optimal reference gene or gene combination for reliable RT-qPCR gene expression in both non-functioning (NFPA) and hormone secreting (GH and ACTH) pituitary adenomas.

MATERIAL AND METHODS

Thirty commonly used reference genes (PCR array reference gene panel, BioRad, Hercules, CA) were quantified by RT-qPCR in 24 pituitary adenomas (12 NFPA, 8 GH and 4 ACTH). The data was analysed using three programs: geNorm (Qbase+), Normfinder and BestKeeper having different algorithms to identify the most stable reference gene or combination of reference genes. Three reference genes ALAS1, PSMC4 and GAPDH, were selected for further validation in a larger cohort of 223 adenomas (141 NFPA, 63 GH and 19 ACTH).

RESULTS

In all adenomas, ALAS1 and PSMC4 were the most stable reference genes as estimated by geNorm and Normfinder, whereas Bestkeeper ranked RPLP0 and ACTB as the two most stable out of 10 carefully selected genes. The best gene combination was PSMC4 and ALAS1 (geNorm) or PSMC4 and GAPDH (Normfinder). The validation experiment (geNorm) showed that the most stable gene combinations were ALAS1 and GAPDH in NFPA, and PSMC4 and GAPDH in hormone secreting adenomas.

CONCLUSIONS

Several of the reference genes expressed good stability yielding several candidate genes. PSMC4 and ALAS1 were overall the most stably expressed genes in pituitary adenoma merely differing in ranking order. PSMC4 and ALAS1 have so far not been reported as reference genes in pituitary adenomas. The various reference gene algorithms showed a mixed selection of top ranked genes, thus suggesting a need for an individualised and rational choice of reference genes.