Optimal management of non-functioning pituitary adenomas

Cabergoline treatment for surgery-naïve non-functioning pituitary macroadenomas

PURPOSE

The treatment strategy of non-functioning pituitary adenomas (NFPAs) includes surgery, radiotherapy, medical therapy, or observation without intervention. Cabergoline, a dopaminergic agonist, was suggested for the treatment of NFPA remnants after trans-sphenoidal surgery. This study investigates the efficacy of cabergoline in surgery-naive patients with NFPA.

METHODS

Retrospective cohort study including surgery-naive patients with NFPA ≥ 10 mm, treated with cabergoline at a dose of ≥ 1 mg/week for at least 24 months. Patients with chiasmal damage were excluded. Data collected included symptoms, in particular visual disturbances, hormonal levels, tumor characteristics and size evaluated by MRI. Tumor growth was defined as an increase in maximal diameter of ≥  2 mm, and shrinkage as reduction of ≥ 2 mm.

RESULTS

Our cohort included 25 patients treated with cabergoline as primary therapy. Mean age was 63.3 ± 17.3 years, 56% (14/25) were males. Mean tumor size at diagnosis was 18.6 ± 6.3 mm (median 17 mm, range 10-36), and the average follow-up period with cabergoline was 4.6 ± 3.4 years. Out of the 25 tumors, five tumors (20%) decreased in size (mean decrease of 5.0 ± 3.0 mm), 12 tumors (48%) remained stable, and eight (32%) increased in size (mean growth of 5.0 ± 3.3 mm) with cabergoline treatment. During the first two years of cabergoline treatment, the median tumor size exhibited a reduction of 0.5 mm. Patients with an increase in tumor size had larger adenomas at diagnosis and a longer follow-up. Two patients (8%) underwent surgery due to tumor enlargement.

CONCLUSION

Primary treatment with cabergoline is a reasonable approach for selected patients with NFPAs without visual threat.

Non-functional Pituitary Adenomas: Analysis of Delayed Diagnosis in Mexico

BACKGROUND

 Although tumors of the central nervous system (CNS) are rare, they can cause significant morbidity and mortality. The clinical presentation of patients with non-functional pituitary adenomas (NFPA) ranges from being completely asymptomatic to causing pituitary, hypothalamic, or visual dysfunction due to their large size. Patients usually arrive with large tumors at the time of diagnosis.  Objectives: Try to describe the characteristics of NFPA and explain the causes of delayed diagnosis.  Methods: We carried out a retrospective study including 58 patients with NFPA and analyzed the tumor volume at the time of diagnosis and its relationship with sociodemographic and health sector variables.  Results: Low socioeconomic status (SES) was associated with high tumor volume (SES 1-2 of 17.4 cm3 vs 3-6 of 11.7 cm3, p=0.018), and the time between first consultation and diagnosis was longer in the public sector than in the private sector (13.5 months vs 5.1 months). The time between the first symptom and the first consultation was shorter when they had visual impairment than when they did not (4.1 vs 18.4 months, p=0.006).

CONCLUSIONS

On the one hand, citizens should be made aware that a visual deficit should make them go to a medical check-up, and on the other hand, strengthen the health system so that they have the NFPA as a differential diagnosis in patients with some visual alteration. Socioeconomic inequality in our country undoubtedly puts the underprivileged at greater risk.

Epigenomic and transcriptomic landscaping unraveled candidate repositioned therapeutics for non-functioning pituitary neuroendocrine tumors

PURPOSE

Non-functioning pituitary neuroendocrine tumors are challengingly diagnosed tumors in the clinic. Transsphenoidal surgery remains the first-line treatment. Despite the development of state-of-the-art techniques, no drug therapy is currently approved for the treatment. There are also no randomized controlled trials comparing therapeutic strategies or drug therapy for the management after surgery. Therefore, novel therapeutic interventions for the therapeutically challenging NF-PitNETs are urgently needed.

METHODS

We integrated epigenome and transcriptome data (both coding and non-coding) that elucidate disease-specific signatures, in addition to biological and pharmacological data, to utilize rational pathway and drug prioritization in NF-PitNETs. We constructed an epigenome- and transcriptome-based PPI network and proposed hub genes. The signature-based drug repositioning based on the integration of multi-omics data was performed.

RESULTS

The construction of a disease-specific network based on three different biological levels revealed DCC, DLG5, ETS2, FOXO1, HBP1, HMGA2, PCGF3, PSME4, RBPMS, RREB1, SMAD1, SOCS1, SOX2, YAP1, ZFHX3 as hub proteins. Signature-based drug repositioning using hub proteins yielded repositioned drug candidates that were confirmed in silico via molecular docking. As a result of molecular docking simulations, palbociclib, linifanib, trametinib, eplerenone, niguldipine, and zuclopenthixol showed higher binding affinities with hub genes compared to their inhibitors and were proposed as potential repositioned therapeutics for the management of NF-PitNETs.

CONCLUSION

The proposed systems' biomedicine-oriented multi-omics data integration for drug repurposing to provide promising results for the construction of effective clinical therapeutics. To the best of our knowledge, this is the first study reporting epigenome- and transcriptome-based drug repositioning for NF-PitNETs using in silico confirmations.

Natural history of nonfunctioning pituitary macroadenomas followed without intervention: A retrospective cohort study

OBJECTIVE

The treatment strategy for nonfunctioning pituitary adenomas (NFPA) includes surgery, radiotherapy, medical treatment, or follow-up. Prior series of patients with NFPAs followed without intervention include small numbers of patients with macroadenomas. This study investigated the natural history of patients with macroadenomas followed without treatment.

DESIGN AND PATIENTS

Retrospective cohort study included patients>18 years, with a diagnosis of NFPA ≥ 10 mm who were naïve to surgery or medical treatment and followed more than 12 months after diagnosis. Patients with chiasmal threat were excluded. Follow-up terminated if the patient underwent surgery, received cabergoline or was lost to follow-up.

MEASUREMENTS

Data collected included evaluation of tumour characteristics and size by MRI, symptoms including visual disturbances, and hormonal levels. Tumour growth was defined as maximal diameter increase of ≥2 mm.

RESULTS

The cohort included 49 patients (30 males, mean age 68.0 ± 12.0 years). At diagnosis, the average tumour size was 17.8 ± 5.9 mm. Mean follow-up time was 4.9 ± 4.9 years. Increase in tumour size occurred in 16 patients (33%), with an average growth of 5.1 ± 4.4 mm. Reduction in tumour size occurred in 10 patients (20%), with a mean decrease of 3.5 ± 1.3 mm. Twenty-three patients remained with stable tumours. Overall, 33 patients (67%) were observed without any intervention; 3 patients were operated and 13 were treated with cabergoline. None of the parameters including age, gender, baseline tumour size, invasiveness, visual disturbances, or hypopituitarism at diagnosis, predicted tumour growth.

CONCLUSION

Observation of NFPAs without surgery or medical therapy is a reasonable approach in selected patients. In our study, no parameter predicted tumour growth.

Aggressive nonfunctioning pituitary neuroendocrine tumors

Nonfunctioning pituitary neuroendocrine tumors (NF-PitNETs) are tumors that are not associated with clinical evidence of hormonal hypersecretion. According to the World Health Organization (WHO), there are some subtypes of PitNETs that exhibit more aggressive behavior than others. Among the types of potentially aggressive PitNETs, three are nonfunctional: silent sparsely granulated somatotropinomas, silent corticotropinomas, and poorly differentiated PIT-1 lineage tumors. Several biological markers have been investigated in NF-PitNETs. However, there is no single biomarker able to independently predict aggressive behavior in NF-PitNETs. Thus, a more complex and multidisciplinary proposal of a comprehensive definition of aggressive NF-PitNETs is necessary. Here, we suggest a combined and more complete criterion for the NF-PitNETs classification. We propose that aggressiveness is due to a multifactorial combination, and we emphasize the need to include new emerging markers that are involved in the aggressiveness of NF-PitNETs and the need to identify.

Past, Present, and Future of Therapies for Pituitary Neuroendocrine Tumors: Need for Omics and Drug Repositioning Guidance

Innovation roadmaps are important, because they encourage the actors in an innovation ecosystem to creatively imagine multiple possible science future(s), while anticipating the prospects and challenges on the innovation trajectory. In this overarching context, this expert review highlights the present unmet need for therapeutic innovations for pituitary neuroendocrine tumors (PitNETs), also known as pituitary adenomas. Although there are many drugs used in practice to treat PitNETs, many of these drugs can have negative side effects and show highly variable outcomes in terms of overall recovery. Building innovation roadmaps for PitNETs' treatments can allow incorporation of systems biology approaches to bring about insights at multiple levels of cell biology, from genes to proteins to metabolites. Using the systems biology techniques, it will then be possible to offer potential therapeutic strategies for the convergence of preventive approaches and patient-centered disease treatment. Here, we first provide a comprehensive overview of the molecular subtypes of PitNETs and therapeutics for these tumors from the past to the present. We then discuss examples of clinical trials and drug repositioning studies and how multi-omics studies can help in discovery and rational development of new therapeutics for PitNETs. Finally, this expert review offers new public health and personalized medicine approaches on cases that are refractory to conventional treatment or recur despite currently used surgical and/or drug therapy.

Significant Benefits of AIP Testing and Clinical Screening in Familial Isolated and Young-onset Pituitary Tumors

CONTEXT

Germline mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene are responsible for a subset of familial isolated pituitary adenoma (FIPA) cases and sporadic pituitary neuroendocrine tumors (PitNETs).

OBJECTIVE

To compare prospectively diagnosed AIP mutation-positive (AIPmut) PitNET patients with clinically presenting patients and to compare the clinical characteristics of AIPmut and AIPneg PitNET patients.

DESIGN

12-year prospective, observational study.

PARTICIPANTS & SETTING

We studied probands and family members of FIPA kindreds and sporadic patients with disease onset ≤18 years or macroadenomas with onset ≤30 years (n = 1477). This was a collaborative study conducted at referral centers for pituitary diseases.

INTERVENTIONS & OUTCOME

AIP testing and clinical screening for pituitary disease. Comparison of characteristics of prospectively diagnosed (n = 22) vs clinically presenting AIPmut PitNET patients (n = 145), and AIPmut (n = 167) vs AIPneg PitNET patients (n = 1310).

RESULTS

Prospectively diagnosed AIPmut PitNET patients had smaller lesions with less suprasellar extension or cavernous sinus invasion and required fewer treatments with fewer operations and no radiotherapy compared with clinically presenting cases; there were fewer cases with active disease and hypopituitarism at last follow-up. When comparing AIPmut and AIPneg cases, AIPmut patients were more often males, younger, more often had GH excess, pituitary apoplexy, suprasellar extension, and more patients required multimodal therapy, including radiotherapy. AIPmut patients (n = 136) with GH excess were taller than AIPneg counterparts (n = 650).

CONCLUSIONS

Prospectively diagnosed AIPmut patients show better outcomes than clinically presenting cases, demonstrating the benefits of genetic and clinical screening. AIP-related pituitary disease has a wide spectrum ranging from aggressively growing lesions to stable or indolent disease course.

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.

A machine learning model to precisely immunohistochemically classify pituitary adenoma subtypes with radiomics based on preoperative magnetic resonance imaging

PURPOSE

The type of pituitary adenoma (PA) cannot be clearly recognized with preoperative magnetic resonance imaging (MRI) but can be classified with immunohistochemical staining after surgery. In this study, a model to precisely immunohistochemically classify the PA subtypes by radiomic features based on preoperative MR images was developed.

METHODS

Two hundred thirty-five pathologically diagnosed PAs, including t-box pituitary transcription factor (Tpit) family tumors (n = 55), pituitary transcription factor 1 (Pit-1) family tumors (n = 110), and steroidogenic factor 1 (SF-1) family tumors (n = 70), were retrospectively studied. T1-weighted, T2-weighted and contrast-enhanced T1-weighted images were obtained from all patients. Through imaging acquisition, feature extraction and radiomic data processing, 18 radiomic features were used to train support vector machine (SVM), k-nearest neighbors (KNN) and Naïve Bayes (NBs) models. Ten-fold cross-validation was applied to evaluate the performance of these models.

RESULTS

The SVM model showed high performance (balanced accuracy 0.89, AUC 0.9549) whereas the KNN (balanced accuracy 0.83, AUC 0.9266) and NBs (balanced accuracy 0.80, AUC 0.9324) models displayed low performance based on the T2-weighted images. The performance of the T2-weighted images was better than that of the other two MR sequences. Additionally, significant sensitivity (P = 0.031) and specificity (P = 0.012) differences were observed when classifying the PA subtypes by T2-weighted images.

CONCLUSIONS

The SVM model was superior to the KNN and NBs models and can potentially precisely immunohistochemically classify PA subtypes with an MR-based radiomic analysis. The developed model exhibited good performance using T2-weighted images and might offer potential guidance to neurosurgeons in clinical decision-making before surgery.

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.

Cabergoline in the Management of Residual Nonfunctioning Pituitary Adenoma: A Single-Center, Open-Label, 2-Year Randomized Clinical Trial

BACKGROUND

Complete tumor removal by transsphenoidal surgery is usually difficult for large nonfunctioning pituitary adenomas (NFPAs). A validated medical treatment may be useful for their management. This study evaluates the clinical efficacy of the dopaminergic agonist cabergoline for residual NFPA.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a randomized, parallel, open-label clinical trial that compared cabergoline with nonintervention in patients with residual NFPA after transsphenoidal surgery over 2 years. The primary outcome was clinical efficacy (tumor reduction). The secondary outcome was the relationship between tumor dopamine D2 receptor (D2R) expression and clinical responsiveness. Tumor measurements and clinical evaluations were performed every 6 months.

RESULTS

In total, 59 and 57 individuals were randomly assigned to the study and control groups, respectively. At the end of the study, residual tumor shrinkage, stabilization, and enlargement were observed in 28.8%, 66.1%, and 5.1% of patients, respectively, in the medical-therapy group and in 10.5%, 73.7%, and 15.8% of patients, respectively, in the control group (P=0.01). The progression-free survival rate was 23.2 and 20.8 months for the study and control groups, respectively (P=0.01). D2R was not associated with cabergoline responsiveness. No major side effects were related to cabergoline use.

CONCLUSIONS

Cabergoline was an effective drug for treating residual NFPA, and its use was associated with a high rate of tumor shrinkage (ClinicalTrials.gov NCT03271918).

FGFR2 gene polymorphism rs2981582 is associated with non-functioning pituitary adenomas in Chinese Han population: a case-control study

The association of the fibroblast growth factor receptor 2 gene (FGFR2) polymorphism rs2981582 with breast cancer has been extensively studied, whereas the role of this polymorphism in non-functioning pituitary adenoma (NFPA) has not been elucidated. We thus investigated a potential association of rs2981582 with NFPA. A total of 79 patients and 142 healthy control participants were enrolled in our study. DNA of the participants was extracted from peripheral blood samples and genotyped by using the MassARRAY method. We found that the AA genotype was associated with a higher risk of developing NFPA (OR = 1.743, 95%CI: 1.151–2.64, P=0.008). After adjusting for risk factors, significant difference was still observed between the two groups (OR = 1.862, 95%CI: 1.172–2.957, P=0.008). Moreover, under the assumptions of the recessive model (OR = 3.051, 95%CI: 1.403–6.635, P=0.005) and the additive model (AG: OR = 0.329, 95%CI: 0.144–0.755, P=0.009; AA: OR = 0.326, 95%CI: 0.141–0.757, P=0.009), rs2981582 was associated with an increased risk of NFPA. Our results proved that FGFR2 rs2981582 AA genotype was associated with a higher risk of NFPA. The recessive model and additive model also showed increased the risk of NFPA.

The Relationship Between Posterior Pituitary Bright Spot on Magnetic Resonance Imaging (MRI) and Postoperative Diabetes Insipidus for Pituitary Adenoma Patients

Background

This study is to investigate the predictive value of posterior pituitary bright spot (PPBS) on magnetic resonance imaging (MRI) for postoperative diabetes insipidus (DI) in patients with pituitary adenoma.

Material/Methods

This was a retrospective study. In total, 65 patients with pituitary adenoma who underwent transsphenoidal surgery were enrolled. Before surgery, all patients had MRI examinations. The length of pituitary stalk and position of PPBS in T1WI sagittal and coronal sections were analyzed. The volume and height of the tumor was calculated in enhanced T1WI. Urine volume was monitored to analyze the clinical factors contributing to DI.

Results

Among the 65 cases of pituitary adenoma, there were 54 cases of positive PPBS and 11 cases of negative PPBS. There were 32 cases of transient DI, and among these, 22 cases were positive PPBS and 10 cases were negative PPBS. However, there were 33 cases without DI, and among these, 32 cases were positive PPBS and one case was negative PPBS. The negative PPBS was significantly higher in cases with DI, compared with positive PPBS (P<0.05). Logistic regression showed that preoperative negative PPBS was an important predictor for postoperative DI (P<0.05).

Conclusions

Postoperative DI should be considered when there is negative preoperative PPBS on MRI. Also, severe pituitary stalk compression indicates higher risk of postoperative DI.

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.

Emergence of Pituitary Adenoma in a Child during Surveillance: Clinical Challenges and the Family Members' View in an AIP Mutation-Positive Family

INTRODUCTION

Germline aryl hydrocarbon receptor-interacting protein (AIP) mutations are responsible for 15-30% of familial isolated pituitary adenomas (FIPAs). We report a FIPA kindred with a heterozygous deletion in AIP, aiming to highlight the indications and benefits of genetic screening, variability in clinical presentations, and management challenges in this setting.

PATIENTS

An 18-year-old male was diagnosed with a clinically nonfunctioning pituitary adenoma (NFPA). Two years later, his brother was diagnosed with a somatolactotrophinoma, and a small Rathke's cleft cyst and a microadenoma were detected on screening in their 17-year-old sister. Following amenorrhoea, their maternal cousin was diagnosed with hyperprolactinaemia and two distinct pituitary microadenomas. A 12-year-old niece developed headache and her MRI showed a microadenoma, not seen on a pituitary MRI scan 3 years earlier.

DISCUSSION

Out of the 14 members harbouring germline AIP mutations in this kindred, 5 have pituitary adenoma. Affected members had different features and courses of disease. Bulky pituitary and not fully suppressed GH on OGTT can be challenging in the evaluation of females in teenage years. Multiple pituitary adenomas with different secretory profiles may arise in the pituitary of these patients. Small, stable NFPAs can be present in mutation carriers, similar to incidentalomas in the general population. Genetic screening and baseline review, with follow-up of younger subjects, are recommended in AIP mutation-positive families.

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.

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.

Non-functioning pituitary adenoma underwent surgery: A multicenter retrospective study over the last four decades (1977-2015)

OBJECTIVE

To assess clinical features, diagnostic procedures, therapies and outcomes in patients with clinically non-functioning pituitary adenomas (NFPAs) surgically treated over the last four decades.

DESIGN AND METHODS

A multicenter retrospective study in NFPA patients periodically followed up in specialized neuroendocrinology units who underwent surgery in the period 1977-2015 was performed.

RESULTS

A total of 131 patients were studied [66 women (50.4%); mean age 52.6±14.8years (range, 15-82)]. Median diameter of the adenoma was 2.6cm (interquartile range, 2.0-3.1). The most frequently type of surgery used was endoscopic endonasal surgery (58.5%) followed by microscopic transsphenoidal surgery (37.4%). Radiation therapy was used in 19 patients (14.5%). Ki-67 labeling index performed in 54 patients was ≤2% in 70% samples. After a median follow-up time of 57months (25 to 128months), tumor diameter significantly decreased to 0.9cm (0-1.8cm), p<0.001. Multivariant analysis showed that endoscopic endonasal surgery (HR 2.74, 1.06-6.87, p=0.036) and radiotherapy (HR 0.04, 0.02-0.65, p=0.024) behaved as positive and negative predictors, respectively, of tumor absence in the follow-up. Endoscopic endonasal surgery (HR 6.71, 1.45-31.05, p=0.015) was the only positive predictor for complete cure in the follow-up.

CONCLUSION

NFPAs surgically treated in Spain are usually macroadenomas diagnosed around the sixth decade of life with no sex predilection. Type of surgery is associated with clinical outcome. Endoscopic endonasal surgery behaves as a positive predictor for the absence of tumor imaging and complete cure in the follow up.

Non-functioning pituitary adenomas: growth and aggressiveness

Pituitary adenomas (PAs) are common, comprising approximately one third of all intracranial tumors. Non-functioning pituitary adenomas (NFPAs) are the most common PAs. Although usually benign, the NFPAs represent therapeutic challenges because of their location close to the optic chiasm and nerves, and the proximity to the pituitary gland. The therapeutic alternatives are surgery and radiation. To date there is no effective medical treatment. NFPAs are classified according to different modalities, but there are no reliable marker of aggressiveness to guide the clinician in monitoring the patient. More information on growth patterns with constituent biological markers are needed to tailor the care of this patient group. Studies characterizing the membrane receptors of NFPAs have shown promising results, which may give rise to the development of medical treatment.