Temozolomide therapy in patients with aggressive pituitary adenomas or carcinomas

Dopamine agonist resistant prolactinomas: any alternative medical treatment?

Consensus guidelines recommend dopamine agonists (DAs) as the mainstay treatment for prolactinomas. In most patients, DAs achieve tumor shrinkage and normoprolactinemia at well tolerated doses. However, primary or, less often, secondary resistance to DAs may be also encountered representing challenging clinical scenarios. This is particularly true for aggressive prolactinomas in which surgery and radiotherapy may not achieve tumor control. In these cases, alternative medical treatments have been considered but data on their efficacy should be interpreted within the constraints of publication bias and of lack of relevant clinical trials. The limited reports on somatostatin analogues have shown conflicting results, but cases with optimal outcomes have been documented. Data on estrogen modulators and metformin are scarce and their usefulness remains to be evaluated. In many aggressive lactotroph tumors, temozolomide has demonstrated optimal outcomes, whereas for other cytotoxic agents, tyrosine kinase inhibitors and for inhibitors of mammalian target of rapamycin (mTOR), higher quality evidence is needed. Finally, promising preliminary results from in vitro and animal reports need to be further assessed and, if appropriate, translated in human studies.

Malignant Prolactinoma With Liver Metastases Masquerading as Metastatic Gastrointestinal Stromal Tumor: A Case Report and Literature Review

Pituitary carcinomas are rare diseases defined as pituitary tumors with metastases. In this report, we describe a case of malignant prolactinoma with liver metastases masquerading as metastatic gastrointestinal stromal tumor (GIST). A 54-years-old woman received dopamine agonists for macroprolactinoma for 2 years, followed by transsphenoidal surgery due to a poor response to medical therapy. Despite the continuation of dopamine agonist after surgery, serum prolactin level progressively increased to above 8,000 ng/ml in 5 years. There was no evidence of disease recurrence on sella magnetic resonance imaging (MRI). She stopped medical therapy. Meanwhile, she was diagnosed with GIST accompanied by liver and peritoneal metastases. After a 2-months treatment with imatinib, she suddenly presented with headache and visual impairment. Sella MRI showed a 3.3-cm sized pituitary mass, and serum prolactin levels were still high. For the recurred mass, she underwent a second surgery followed by radiation therapy. During the imatinib treatment for GIST, main mass and peritoneal metastases were dramatically decreased, but liver metastases were markedly aggravated. Liver masses were eventually confirmed as metastases from prolactin-producing pituitary carcinoma and not from GIST by percutaneous biopsy. Unfortunately, she died 6 months after the second surgery due to acute renal failure and sepsis. This case suggests that highly sustained serum prolactin levels during the dopamine agonist may indicate prolactin-producing pituitary carcinomas with hidden metastases.

Medical Management of Cushing's Syndrome: Current and Emerging Treatments

Endogenous Cushing's syndrome is a chronic disease associated with increased morbidity and mortality if not appropriately treated. Recurrence and/or persistence of hypercortisolemia after surgical treatment, especially for Cushing's disease, are high, and long-term medical treatment is used to decrease cortisol levels and risk of metabolic comorbidities. Medical treatment is also often required while waiting for radiation effects to take place. In some cases, severe or life-threatening hypercortisolism must be urgently and medically treated, via intravenous medications or with combination therapy, before patients can undergo surgery. In the last decade, medical treatment has progressed from a few steroidogenesis inhibitors to three novel drug groups: new inhibitors for steroidogenic enzymes with possibly fewer side effects, pituitary-directed drugs that aim to inhibit the pathophysiological pathways of Cushing's disease, and glucocorticoid receptor antagonists that block cortisol's action. Understanding the pathophysiology of Cushing's syndrome has also led to the identification of potential targets that may decrease adrenocorticotrophic hormone and/or cortisol excess, and/or decrease tumor cell proliferation, and induce senescence or apoptosis. We provide here a review of current and near-future medical options to treat Cushing's syndrome, and discuss updates on clinical trials and the efficacy and safety of novel or in-development drugs, as well as future potential targets.

Multimodal therapy in aggressive pituitary tumors

The concept of aggressive pituitary tumor (APT) has been precisely defined in recent years. These tumors are characterized by morphological (radiological or histopathological) data of invasion, proliferative activity superior to that of typical adenomas and a clinical behavior characterized by resistance to standard therapies and frequent recurrences. The absence of cerebrospinal or distant metastases differentiates them from the pituitary carcinoma. APTs account for about 10% of all pituitary neoplasm. Proper diagnostic implies participation not only of radiological and hormonal investigation but also a thorough pathological assessment including proliferation markers and immunohistochemistry for hormones and transcription factors. Surgical resection, aiming gross total resection or tumor debulking, is the mainstay initial therapy in most patients. Most patients with APTs need more than one surgical intervention, pituitary radiation, sometimes on more than one occasion, and multiple sequential or combined medical treatments, to finally be doomed to unusual treatments, such as alkylating agents (temozolomide alone or in combination), molecular targeted therapies, or peptide receptor radionuclide therapy. Multimodal therapy, implemented by experts, preferably in specialized centers with high volume caseload, is the only way to improve the prognosis of patients with these uncommon tumors. The research needs in this area are multiple and include a greater knowledge of the molecular biology of these tumors, establishment of protocols for monitoring and sequencing of treatments, development of multicenter studies and international registries.

Cushing's Disease

In patients with Cushing's disease (CD), prompt diagnosis and treatment are essential for favorable long-term outcomes, although this remains a challenging task. The differential diagnosis of CD is still difficult in some patients, even with an organized stepwise diagnostic approach. Moreover, despite the use of high-resolution magnetic resonance imaging (MRI) combined with advanced fine sequences, some tumors remain invisible. Surgery, using various surgical approaches for safe maximum tumor removal, still remains the first-line treatment for most patients with CD. Persistent or recurrent CD after unsuccessful surgery requires further treatment, including repeat surgery, medical therapy, radiotherapy, or sometimes, bilateral adrenalectomy. These treatments have their own advantages and disadvantages. However, the most important thing is that this complex disease should be managed by a multidisciplinary team with collaborating experts. In addition, a personalized and individual-based approach is paramount to achieve high success rates while minimizing the occurrence of adverse events and improving the patients' quality of life. Finally, the recent new insights into the pathophysiology of CD at the molecular level are highly anticipated to lead to the introduction of more accurate diagnostic tests and efficacious therapies for this devastating disease in the near future.

Management of Nonfunctioning Recurrent Pituitary Adenomas

Pituitary adenomas are typically slow-growing benign tumors. However, 50% to 60% of tumors progress following subtotal resection and up to 30% recur after apparent complete resection. Options for treatment of recurrent pituitary adenomas include repeat surgical resection, radiation therapy, and systemic therapies. There is no consensus approach for the management of recurrent pituitary adenomas. This article reviews the natural history of recurrent adenomas and emerging biomarkers predictive of clinical behavior as well as the outcomes associated with the various treatment modalities for these challenging tumors, with an emphasis on the surgical treatment.

Lower all-cause mortality rates in patients harboring pituitary carcinoma following the introduction of temozolomide

OBJECTIVE

To evaluate the impact of temozolomide (TMZ) introduction on the survival of patients with pituitary carcinoma (PC) compared to aggressive pituitary adenoma (APA).

METHODS

Retrospective analysis of the Surveillance Epidemiology and End-Results database (SEER), including patients diagnosed with PC or APA between 1973 and 2015. Age-adjusted Kaplan-Meier analyses were performed, comparing all-cause mortality (ACM) rates before the year 2006, the time of TMZ introduction ("period 1"), and afterwards ("period 2"), in patients harboring PC and APA.

RESULTS

Among 107 patients, 18 (16.8%) harbored PC. The prevalence of PC and APA was comparable between genders, ethnicities and age strata. Patients harboring any pituitary tumor (PC or APA) had comparable risk for ACM and disease-specific mortality between the two time periods. However, among patients harboring PC, the risk for ACM was significantly lower in period 2 vs. period 1 (p = 0.021), becoming comparable to the risk of ACM in patients diagnosed with APA (p = 0.48).

CONCLUSIONS

In this large cancer-database-based analysis we observed improved overall survival in patients harboring PC in the years following the introduction of TMZ.

Identification of microRNAs associated with the aggressiveness of prolactin pituitary tumors using bioinformatic analysis

Aggressive prolactin pituitary tumors, which exhibit aggressive behaviors and resistance to conventional treatments, are a huge challenge for neurosurgeons. Many studies have investigated the roles of microRNAs (miRNAs) in pituitary tumorigenesis, invasion and metastasis, but few have explored aggressiveness‑associated miRNAs in aggressive pituitary tumors. Differentially expressed miRNAs (DEMs) between aggressive and nonaggressive prolactin pituitary tumors were screened using the GSE46294 miRNA expression profile downloaded from the GEO database. The potential target genes of the top three most highly upregulated and downregulated DEMs were predicted by miRTarBase, and potential functional annotation and pathway enrichment analysis were performed using the DAVID database. Protein‑protein interaction (PPI) and miRNA‑hub gene interaction networks were constructed by Cytoscape software. A total of 43 DEMs were identified, including 19 upregulated and 24 downregulated miRNAs, between aggressive and nonaggressive prolactin pituitary tumors. One hundred and seventy and 680 target genes were predicted for the top three most highly upregulated and downregulated miRNAs, respectively, and these genes were involved in functional enrichment pathways, such as regulation of transcription from RNA polymerase II promoter, DNA‑templated transcription, Wnt signaling pathway, protein binding, and transcription factor activity (sequence‑specific DNA binding). In the PPI network, the top 10 genes with the highest degree of connectivity of the upregulated and downregulated DEMs were selected as hub genes. By constructing an miRNA‑hub gene network, it was found that most hub genes were potentially modulated by hsa‑miR‑489 and hsa‑miR‑520b. Targeting hsa‑miR‑489 and hsa‑miR‑520b may provide new clues for the diagnosis and treatment of aggressive prolactin pituitary tumors.

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.

Peptide receptor radionuclide therapy for aggressive pituitary tumors: a monocentric experience

In aggressive pituitary tumors (PT) showing local invasion or growth/recurrence despite multimodal conventional treatment, temozolomide (TMZ) is considered a further therapeutic option, while little data are available on peptide receptor radionuclide therapy (PRRT). We analyzed PRRT effectiveness, safety and long-term outcome in three patients with aggressive PT, also reviewing the current literature. Patient #1 (F, giant prolactinoma) received five cycles (total dose 37 GBq) of 111In-DTPA-octreotide over 23 months, after unsuccessful surgery and long-term dopamine-agonist treatment. Patient #2 (M, giant prolactinoma) underwent two cycles (12.6 GBq) of 177Lu-DOTATOC after multiple surgeries, radiosurgery and TMZ. In patient #3 (F, non-functioning PT), five cycles (29.8 GBq) of 177Lu-DOTATOC followed five surgeries, radiotherapy and TMZ. Eleven more cases of PRRT-treated aggressive PT emerged from literature. Patient #1 showed tumor shrinkage and visual/neurological amelioration over 8-year follow-up, while the other PTs continued to grow causing blindness and neuro-cognitive disorders (patient #2) or monolateral amaurosis (patient #3). No adverse effects were reported. Including the patients from literature, 4/13 presented tumor shrinkage and clinical/biochemical improvement after PRRT. Response did not correlate with patients' gender or age, neither with used radionuclide/peptide, but PRRT failure was significantly associated with previous TMZ treatment. Overall, adverse effects occurred only in two patients. PRRT was successful in 1/3 of patients with aggressive PT, and in 4/5 of those not previously treated with TMZ, representing a safe option after unsuccessful multimodal treatment. However, at present, considering the few data, PRRT should be considered only in an experimental setting.

Functioning Pituitary Adenomas - Current Treatment Options and Emerging Medical Therapies

Pituitary adenomas are benign tumours comprising approximately 16% of all primary cranial neoplasms. Functioning pituitary adenomas (prolactinomas, somatotroph, corticotroph, thyrotroph and rarely gonadotroph adenomas) cause complex clinical syndromes and require prompt treatment to reduce associated morbidity and mortality. Treatment approaches include transsphenoidal surgery, medical therapy and radiation. Medical therapy is the primary therapy for prolactinomas, and surgery by a skilled neurosurgeon is the first-line approach for other functioning pituitary adenomas. A multimodal treatment is frequently necessary to achieve biochemical and clinical control, especially, when surgery is not curative or when medical therapy fails. Several emerging, novel, medical treatments for acromegaly, Cushing's disease and prolactinomas are in phase II and III clinical trials and may become effective additions to the current drug armamentarium. The availability of various management options will allow an individualised treatment approach based on the unique tumour type, clinical situation and patient preference.

Advances in the medical treatment of Cushing's syndrome

Cushing's syndrome is associated with multisystem morbidity and, when suboptimally treated, increased mortality. Medical therapy is an option for patients if surgery is not successful and can be classified into pituitary-directed drugs, steroid synthesis inhibitors, and glucocorticoid receptor antagonists. In the last decade there have been new developments in each drug category. Targeting dopamine and somatostatin receptors on corticotroph adenomas with cabergoline or pasireotide, or both, controls cortisol production in up to 40% of patients. Potential new targets in corticotroph adenomas include the epidermal growth factor receptor, cyclin-dependent kinases, and heat shock protein 90. Osilodrostat and levoketoconazole are new inhibitors of steroidogenesis and are currently being evaluated in multicentre trials. CORT125134 is a new selective glucocorticoid receptor antagonist under investigation. We summarise the drug therapies for various forms of Cushing's syndrome and focus on emerging drugs and drug targets that have the potential for new and effective tailor-made pharmacotherapy for patients with Cushing's syndrome.

Tumor-Directed Therapeutic Targets in Cushing Disease

CONTEXT

The most frequent cause of endogenous hypercortisolism is Cushing disease (CD), a devastating condition associated with severe comorbidities and high mortality. Effective tumor-targeting therapeutics are limited.

DESIGN

Search in PubMed with key words "corticotroph" and "Cushing's disease" plus the name of the mentioned therapeutic agent and in associated references of the obtained papers. Additionally, potential therapeutics were obtained from ClinicalTrials.gov with a search for "Cushing disease."

RESULTS

At present, the tumor-targeted pharmacological therapy of CD is concentrated on dopamine agonists (cabergoline) and somatostatin analogs (pasireotide) with varying efficacy, escape from response, and considerable side effects. Preclinical studies on corticotroph pathophysiology have brought forward potential drugs such as retinoic acid, silibinin, and roscovitine, whose efficacy and safety remain to be determined.

CONCLUSIONS

For many patients with CD, effective tumor-targeted pharmacological therapy is still lacking. Coordinated efforts are pivotal in establishing efficacy and safety of novel therapeutics in this rare but devastating disease.

Biomarker Discovery for Immunotherapy of Pituitary Adenomas: Enhanced Robustness and Prediction Ability by Modern Computational Tools

Pituitary adenoma (PA) is prevalent in the general population. Due to its severe complications and aggressive infiltration into the surrounding brain structure, the effective management of PA is required. Till now, no drug has been approved for treating non-functional PA, and the removal of cancerous cells from the pituitary is still under experimental investigation. Due to its superior specificity and safety profile, immunotherapy stands as one of the most promising strategies for dealing with PA refractory to the standard treatment, and various studies have been carried out to discover immune-related gene markers as target candidates. However, the lists of gene markers identified among different studies are reported to be highly inconsistent because of the greatly limited number of samples analyzed in each study. It is thus essential to substantially enlarge the sample size and comprehensively assess the robustness of the identified immune-related gene markers. Herein, a novel strategy of direct data integration (DDI) was proposed to combine available PA microarray datasets, which significantly enlarged the sample size. First, the robustness of the gene markers identified by DDI strategy was found to be substantially enhanced compared with that of previous studies. Then, the DDI of all reported PA-related microarray datasets were conducted to achieve a comprehensive identification of PA gene markers, and 66 immune-related genes were discovered as target candidates for PA immunotherapy. Finally, based on the analysis of human protein⁻protein interaction network, some promising target candidates (GAL, LMO4, STAT3, PD-L1, TGFB and TGFBR3) were proposed for PA immunotherapy. The strategy proposed together with the immune-related markers identified in this study provided a useful guidance for the development of novel immunotherapy for PA.

Aggressive and Malignant Prolactinomas

Prolactin-secreting tumors (prolactinomas) represent the most common pituitary tumor type, accounting for 47-66% of functional pituitary tumors. Prolactinomas are usually benign and controllable tumors as they express abundant levels of dopamine type 2 receptor (D2), and can be treated with dopaminergic drugs, effectively reducing prolactin levels and tumor volume. However, a proportion of prolactinomas exhibit aggressive features (including invasiveness, relevant growth despite adequate dopamine agonist treatment, and recurrence potential) and few may exhibit metastasizing potential (carcinomas). In this context, the clinical, pathological, and molecular definitions of malignant and aggressive prolactinomas remain to be clearly defined, as primary prolactin-secreting carcinomas are similar to aggressive adenomas until the presence of metastases is detected. Indeed, standard molecular and histological analyses do not reflect differences between carcinomas and adenomas at a first glance and have limitations in prediction of the aggressive progression of prolactinomas, wherein the causes underlying the aggressive behavior remain unknown. Herein we present a comprehensive, multidisciplinary review of the most relevant epidemiological, clinical, pathological, genetic, biochemical, and molecular aspects of aggressive and malignant prolactinomas.

The Treatment of Refractory Pituitary Adenomas

Refractory pituitary adenomas (PAs) are defined as aggressive-invasive PAs characterized by a high Ki-67 index, rapid growth, frequent recurrence, and resistance to conventional treatments. It is notoriously difficult to manage refractory PAs because the efficacy of current therapeutic options is limited. The purpose of this review is to address currently employed and promising therapeutic strategies for the treatment of refractory PAs. Except for prolactinomas, neurosurgery is the first-line option, but most refractory PAs often recur or re-grow after initial surgery and require further treatments. Medical therapy, radiotherapy and re-operation are explored when surgery has failed to completely resect tumors; however, refractory PAs are usually resistant to these treatments. As a salvage treatment, temozolomide (TMZ) has shown promising results and is currently used for all types of refractory PAs. However, not all refractory PAs are responsive to TMZ treatment, and some of these PAs are resistant to TMZ. Although targeted therapies such as vascular endothelial growth factor, epidermal growth factor and mTOR inhibitors have also been used to treat refractory PAs, the effectiveness of these targeted therapies is still not known due to a lack of data from randomized prospective trials. As a novel therapeutic method, cancer immunotherapy is a promising strategy for the treatment of refractory PAs, but further preclinical research and clinical trials are needed to assess the efficacy of this new approach. In summary, early identification and a multidisciplinary approach are required to treat refractory PAs.

Aggressive and malignant pituitary tumours: state-of-the-art

Pituitary adenomas are unique in multiple ways. They are rarely malignant in terms of metastases; yet, they may be aggressive. Their cancerous potential is defined in a classic oncological way by the ability to metastasise, and therefore, it has been crucial to differentiate this process from aggressive behaviour, characterised as a particularly invasive and/or recurrent behaviour and resistance to common modalities of therapy. Recently, however, important changes have been introduced to the diagnosis and management of aggressive and malignant pituitary tumours including the 4th edition of the World Health Organization (WHO) classification for endocrine tumours (2017) as well as ESE Clinical Guidelines (2018), although an attempt to establish predictive and/or prognostic markers of clinical aggressiveness remains difficult. In this review, we focus on a group of pituitary tumours causing significant problems in clinical practice and requiring multidisciplinary input. We summarise updates in definitions of tumour invasiveness, aggressiveness and malignant transformation, as well as histological classification, and emphasise the new considerations regarding aggressive and malignant potential and its relationship to therapeutic strategies.

65 YEARS OF THE DOUBLE HELIX: Treatment of pituitary tumors with temozolomide: an update

Temozolomide is an alkylating chemotherapeutic agent used in malignant neuroendocrine neoplasia, melanoma, brain metastases and an essential component of adjuvant therapy in the treatment of glioblastoma multiforme and anaplastic astrocytoma. Since 2006, it has been used for the treatment of pituitary carcinomas and aggressive pituitary adenomas. Here, we discuss the current indications and results of temozolomide therapy in pituitary tumors, as well as frequently asked questions regarding temozolomide treatment, duration of therapy, dosage, tumor recurrence and resistance.

Corticotrophic pituitary carcinoma with cervical metastases: case series and literature review

PURPOSE

Pituitary tumors are the second most common intracranial tumors, however, pituitary carcinoma is a rare clinical entity which represents only 0.1-0.2% of all pituitary tumors. Diagnosis of pituitary carcinoma requires the presence of metastasis. Early identification of pituitary carcinoma is difficult, and only recently have guidelines been published for the treatment of aggressive pituitary tumors. We present two cases from our institution, with a review of other cases available in literature in order to better characterize this rare disease.

METHODS

A retrospective review of two patients with pituitary carcinoma treated at a tertiary medical center was performed. The MEDLINE database was searched for all cases of pituitary carcinoma. Information for age at diagnosis, sex, pituitary tumor type, latency period from pituitary tumor to presentation of carcinoma, sites of metastasis, number of surgical therapies, radiation and chemotherapy, and survival after diagnosis were collected.

RESULTS

A total of 69 studies were available for review for a total of 72 unique cases. The average age at diagnosis was 46.3 years. The most common tumors were ACTH-secreting (34.7%), Prolactin-secreting (23.6%), and Null Cell (15.3%). The average latency period from pituitary tumor diagnosis to metastasis was 9 years. All patients underwent surgical therapy during their treatment, with an average of 2.76 procedures. The mortality rate was 54.8% with average time to death after diagnosis of approximately 10 months.

CONCLUSIONS

Pituitary carcinoma is a rare disease with high mortality rate and is a diagnostic and treatment challenge. Further study is required but is difficult due to its low incidence.

Recurrent non-functioning pituitary adenomas: a review on the new pathological classification, management guidelines and treatment options

At least 50% of surgically resected non-functioning pituitary adenomas (NFPA) recur. Either early or late adjuvant radiotherapy is highly efficacious in controlling recurrent NFPA but associates potentially burdensome complications like hypopituitarism, vascular complications or secondary neoplasm. Reoperation is indicated in bulky tumor rests compressing the optic pathway. To date, no standardized medical therapy is available for recurrent NFPA although cabergoline and temozolomide show promising results. Guidelines on the management of recurrent NFPAs are now available. The new 2017 WHO pituitary tumor classification, based on immunohistochemistry and transcription factor assessment, identifies a group of aggressive NFPA variants that may benefit from earlier adjuvant therapy. Nevertheless, NFPA patients exhibit a reduced overall life expectancy largely due to hypopituitarism and treatment-related morbidity. The management of recurrent NFPA benefits from a multidisciplinary teamwork of surgeons, endocrinologists, radiation oncologists, ophthalmologists, pathologists and neuro-radiologists in order to provide individualized therapy and anticipate deterioration.

Malignant transformation in non-functioning pituitary adenomas (pituitary carcinoma)

Non-functioning pituitary carcinomas (NFPC) are defined as tumours of adenophyseal origin with craniospinal or systemic dissemination, with the absence of a hormonal hypersecretion syndrome. These are a histologically heterogenous group of tumours, comprising gonadotroph, null cell, "silent" tumours of corticotroph, somatotroph or lactotroph cell lineages as well as plurihormonal Pit-1 tumours. NFPC are exceedingly rare, and hence few cases have been described. This review has identified 38 patients with NFPC reported in the literature. Recurrent invasive non-functioning pituitary adenomas (NFPA) were observed in a majority of patients. Various factors have been identified as markers of the potential for aggressive behaviour, including rapid tumour growth, growth after radiotherapy, gain or shift of hormone secretion and raised proliferative markers. Typically, there is a latency of several years from the original presentation with an NFPA to identification of metastases and only 5 cases reported with rapidly progressive malignant disease within 1 month of presentation. Therapeutic options include debulking surgery, radiation therapy and chemotherapy with temozolomide recommended as first line systemic treatment. Although long-term survivors are described, prognosis remains generally very poor (median survival 8 months). Improvements in molecular tumour profiling may assist in predicting tumour behaviour, guide therapeutic choices and identify novel therapies.

Treatment of aggressive pituitary tumours and carcinomas: results of a European Society of Endocrinology (ESE) survey 2016

OBJECTIVE

To collect outcome data in a large cohort of patients with aggressive pituitary tumours (APT)/carcinomas (PC) and specifically report effects of temozolomide (TMZ) treatment.

DESIGN

Electronic survey to ESE members Dec 2015-Nov 2016.

RESULTS

Reports on 166 patients (40 PC, 125 APT, 1 unclassified) were obtained. Median age at diagnosis was 43 (range 4-79) years. 69% of the tumours were clinically functioning, and the most frequent immunohistochemical subtype were corticotroph tumours (45%). Ki-67 index did not distinguish APT from PC, median 7% and 10% respectively. TMZ was first-line chemotherapy in 157 patients. At the end of the treatment (median 9 cycles), radiological evaluation showed complete response (CR) in 6%, partial response (PR) in 31%, stable disease (SD) in 33% and progressive disease in 30%. Response was more frequent in patients receiving concomitant radiotherapy and TMZ. CR was seen only in patients with low MGMT expression. Clinically functioning tumours were more likely to respond than non-functioning tumours, independent of MGMT status. Of patients with CR, PR and SD, 25, 40 and 48% respectively progressed after a median of 12-month follow-up. Other oncological drugs given as primary treatment and to TMZ failures resulted in PR in 20%.

CONCLUSION

This survey confirms that TMZ is established as first-line chemotherapeutic treatment of APT/PC. Clinically functioning tumours, low MGMT and concurrent radiotherapy were associated with a better response. The limited long-term effect of TMZ and the poor efficacy of other drugs highlight the need to identify additional effective therapies.

Pediatric Pituitary Adenoma: Case Series, Review of the Literature, and a Skull Base Treatment Paradigm

Background  Pediatric pituitary adenoma is a rare skull base neoplasm, accounting for 3% of all intracranial neoplasms in children and 5% of pituitary adenomas. Compared with pituitary tumors in adults, secreting tumors predominate and longer disease trajectories are expected due to the patient age resulting in a natural history and treatment paradigm that is complex and controversial. Objectives  The aims of this study were to describe a large, single-institution series of pediatric pituitary adenomas with extensive long-term follow-up and to conduct a systematic review examining outcomes after pituitary adenoma surgery in the pediatric population. Methods  The study cohort was compiled by searching institutional pathology and operative reports using diagnosis and site codes for pituitary and sellar pathology, from 1956 to 2016. Systematic review of the English language literature since 1970 was conducted using PubMed, MEDLINE, Embase, and Google Scholar. Results  Thirty-nine surgically managed pediatric pituitary adenomas were identified, including 15 prolactinomas, 14 corticotrophs, 7 somatotrophs, and 4 non-secreting adenomas. All patients underwent transsphenoidal resection (TSR) as the initial surgical treatment. Surgical cure was achieved in 18 (46%); 21 experienced recurrent/persistent disease, with secondary treatments including repeat surgery in 10, radiation in 14, adjuvant pharmacotherapy in 11, and bilateral adrenalectomy in 3. At the last follow-up (median 87 months, range 3-581), nine remained with recurrent/persistent disease (23%). Thirty-seven publications reporting surgical series of pediatric pituitary adenomas were included, containing 1,284 patients. Adrenocorticotropic hormone (ACTH)-secreting tumors were most prevalent (43%), followed by prolactin (PRL)-secreting (37%), growth hormone (GH)-secreting (12%), and nonsecreting (7%). Surgical cure was reported in 65%. Complications included pituitary insufficiency (23%), permanent visual dysfunction (6%), chronic diabetes insipidus (DI) (3%), and postoperative cerebrospinal fluid (CSF) leak (4%). Mean follow-up was 63 months (range 0-240), with recurrent/persistent disease reported in 18% at the time of last follow-up. Conclusion  Pediatric pituitary adenomas are diverse and challenging tumors with complexities far beyond those encountered in the management of routine adult pituitary disease, including nuanced decision-making, a technically demanding operative environment, high propensity for recurrence, and the potentially serious consequences of hypopituitarism with respect to fertility and growth potential in a pediatric population. Optimal treatment requires a high degree of individualization, and patients are most likely to benefit from consolidated, multidisciplinary care in highly experienced centers.

Early recognition of aggressive pituitary adenomas: a single-centre experience

BACKGROUND

Pituitary adenomas are usually considered benign tumours, although some of them can exhibit an aggressive behaviour. Patients with clinically aggressive pituitary adenomas are frequently diagnosed with larger masses, and may present an earlier recurrence (or persistence) after surgery. Our aim was to characterise the clinical, histopathological and radiological features of patients with aggressive pituitary adenoma, in order to correlate their clinical behaviour with the response to treatment plan.

METHOD

We considered an aggressive pituitary adenoma on the basis of radiological features (size, local invasion), pathological reports (atypical adenoma: MIB-1 >3%, p53 immunoreactivity, increased mitotic activity) and clinical aspects (response to surgery, radiotherapy and medical treatment).

RESULTS

Among our cohort of 582 patients, we considered 102 subjects with aggressive pituitary adenomas (18%, 56 male and 46 female): 14 adrenocorticotrophic hormone (ACTH)-secreting, 18 growth hormone (GH)-secreting, 23 prolactin (PRL)-secreting and 47 non-secreting, with a median follow-up of 5 years. In the whole cohort, 75% of patients with aggressive pituitary adenomas presented invasion of surrounding structure, especially GH-secreting, PRL-secreting and non-secreting. Besides invasion, their remission rate after surgery, radiotherapy or medical treatment was similar, irrespective of hormonal secretion. Surgery was the most performed treatment (overall remission rate of 24%), especially in those patients with ACTH- or GH-secreting adenoma, and 22% of patients were submitted to radiotherapy, with a remission rate of 45% after a median of 3 years. Two consecutive years of medical treatment, in patients with secreting pituitary adenoma, achieved disease control in 41% of them. Considering pathological reports, 24% of cases were defined as atypical adenomas; radiological characteristics, responses to medical treatment and remission rates were similar among patients with typical and atypical adenoma.

CONCLUSIONS

We proposed a new and comprehensive definition of aggressive pituitary adenoma, based upon radiological, clinical and pathological features. In a selected cohort of patients, radiological invasion resulted in the most common marker to describe the aggressive behaviour of pituitary adenoma. Surgery, radiotherapy and medical treatment (the latter only in secreting adenoma) achieved disease control in half of the patients with aggressive adenoma, especially surgery in those with ACTH-oma and medical treatment in those with GH- and PRL-secreting adenoma. Nevertheless, radiological, clinical or atypical features did not affect the outcome.

Temozolomide and Pituitary Tumors: Current Understanding, Unresolved Issues, and Future Directions

Temozolomide, an alkylating agent, initially used in the treatment of gliomas was expanded to include pituitary tumors in 2006. After 12 years of use, temozolomide has shown a notable advancement in pituitary tumor treatment with a remarkable improvement rate in the 5-year overall survival and 5-year progression-free survival in both aggressive pituitary adenomas and pituitary carcinomas. In this paper, we review the mechanism of action of temozolomide as alkylating agent, its interaction with deoxyribonucleic acid repair systems, therapeutic effects in pituitary tumors, unresolved issues, and future directions relating to new possibilities of targeted therapy.

European Society of Endocrinology Clinical Practice Guidelines for the management of aggressive pituitary tumours and carcinomas

BACKGROUND

Pituitary tumours are common and easily treated by surgery or medical treatment in most cases. However, a small subset of pituitary tumours does not respond to standard medical treatment and presents with multiple local recurrences (aggressive pituitary tumours) and in rare occasion with metastases (pituitary carcinoma). The present European Society of Endocrinology (ESE) guideline aims to provide clinical guidance on diagnosis, treatment and follow-up in aggressive pituitary tumours and carcinomas.

METHODS

We decided upfront, while acknowledging that literature on aggressive pituitary tumours and carcinomas is scarce, to systematically review the literature according to the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system. The review focused primarily on first- and second-line treatment in aggressive pituitary tumours and carcinomas. We included 14 single-arm cohort studies (total number of patients = 116) most on temozolomide treatment (n = 11 studies, total number of patients = 106). A positive treatment effect was seen in 47% (95% CI: 36-58%) of temozolomide treated. Data from the recently performed ESE survey on aggressive pituitary tumours and carcinomas (165 patients) were also used as backbone for the guideline. SELECTED RECOMMENDATION: (i) Patients with aggressive pituitary tumours should be managed by a multidisciplinary expert team. (ii) Histopathological analyses including pituitary hormones and proliferative markers are needed for correct tumour classification. (iii) Temozolomide monotherapy is the first-line chemotherapy for aggressive pituitary tumours and pituitary carcinomas after failure of standard therapies; treatment evaluation after 3 cycles allows identification of responder and non-responder patients. (iv) In patients responding to first-line temozolomide, we suggest continuing treatment for at least 6 months in total. Furthermore, the guideline offers recommendations for patients who recurred after temozolomide treatment, for those who did not respond to temozolomide and for patients with systemic metastasis.

Detection of programmed death ligand 1 protein and CD8+ lymphocyte infiltration in plurihormonal pituitary adenomas: A case report and review of the literatures

RATIONALE

Pituitary adenomas secreting two or more hormones were referred to the plurihormonal tumors. The management of this type of the tumor was tumor resection and amelioration of the unbalanced hormones. However, it washard to cure the plurihormonal adenomas, as they were usually refractory to the traditional treatment. New therapeutic methods were needed in dealing this tumor.

PATIENT CONCERNS

In this report, we described a patient who suffered from plurihormonal pituitary adenomas, with concomitant prolactin (PRL) and growth hormone (GH) secretion. The adenomas showed aggressive behaviors, which was giant, invasive, and refractory to bromocriptine treatments.

INTERVENTIONS

The patient underwent a surgical treatment.

DIAGNOSIS

The pathology together with clinical presentation and blood hormone test confirmed that it was PRL-GH secreting tumors.

OUTCOMES

Although a gross resection was achieved, the postoperative hormones were not normalized. There were also abundant programmed death ligand-1 proteins and CD8 lymphocyte infiltration in the tumor tissues.

LESSONS

Our results indicated immunotherapy as a promising treatment for this tumor. More studies were needed to investigate the possibility of the immunotherapy in pituitary adenomas.

Treatment of aggressive prolactinoma with temozolomide: A case report and review of literature up to date

RATIONALE

Aggressive pituitary adenomas and pituitary carcinomas are rare and demand multiple treatment strategies. Temozolomide, an orally active alkylating chemotherapeutic agent, has recently been recommended as a salvage medication for refractory pituitary adenomas or carcinomas.

PATIENT CONCERNS

A 17-year-old male presenting with aggressive prolactinoma that continued to progress despite surgery, gamma knife, and dopamine agonists.

DIAGNOSES

The diagnosis of refractory aggressive prolactinoma was made on the basis of clinical findings and the lack of efficacy of conventional treatment.

INTERVENTIONS

The patient received the most frequently recommended regimen of temozolomide treatment for 22 cycles.

OUTCOMES

Temozolomide resulted in a remarkable shrinkage of tumor mass and inhibition of prolactin secretion and this patient's clinical condition improved progressively.

LESSONS

Temozolomide can be used as a salvage treatment to refractory pituitary tumors and o(6)-methylguanine-DNA methyltransferase (MGMT) status is a significant predictor to the effectiveness of temozolomide based on the existing literature.

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.

Frequency, pattern, and outcome of recurrences after gamma knife radiosurgery for pituitary adenomas

Gamma Knife radiosurgery is often used in pituitary adenomas. Aim of our study is to describe the characteristics and long-term outcome of patients with adenoma recurrence after Gamma Knife radiosurgery. We conducted a retrospective analysis of patients with pituitary adenoma treated by Gamma Knife radiosurgery between 1994 and 2014. Tumor recurrence was labeled as "in field" when the tumor growth occurred adjacent or within the prescribed isodose, whereas it was classified as "out of field" when the tumor growth occurred outside the prescribed isodose. Five hundred forty-three patients were included, 272 (50.1 %) had a nonfunctioning pituitary adenoma (NFPA) and 271 (49.9 %) patients had a hormone secreting-pituitary adenoma. The median follow-up after GKRS was 78 months (IQR, 36-125 months). Thirty-nine patients (7.2 %) had recurrence of disease and it was more frequent in patients with NFPA than in patients with hormone secreting adenomas (9.6 % vs. 4.8 %). The 10-yr progression-free survival in patients with NFPA was 78.7 % (95 % CI 69.5 - 87.9 %), as compared with 93.3 % (95 % CI 89.3 - 97.3 %; p < 0.01) in hormone secreting adenomas. Tumor recurrence was "in field" in 17 cases (43.6 %) and "out of field" in 22 cases (56.4 %). Seven of the 39 patients with recurrence died despite further treatments. Six of these patients had an "in field" recurrence. Recurrence of a pituitary adenoma after GKRS may occur several years after initial treatment. Distinction between "in field" and "out of field" tumor recurrence probably reflects two different pathophysiological mechanisms and may have prognostic importance.

Temozolomide treatment can improve overall survival in aggressive pituitary tumors and pituitary carcinomas

OBJECTIVES

Only few retrospective studies have reported an efficacy rate of temozolomide (TMZ) in pituitary tumors (PT), all around 50%. However, the long-term survival of treated patients is rarely evaluated. We therefore aimed to describe the use of TMZ on PT in clinical practice and evaluate the long-term survival.

DESIGN

Multicenter retrospective study by members of the French Society of Endocrinology.

METHODS

Forty-three patients (14 women) treated with TMZ between 2006 and 2016 were included. Most tumors were corticotroph (n = 23) or lactotroph (n = 13), and 14 were carcinomas. Clinical/pathological characteristics of PT, as well as data from treatment evaluation and from the last follow-up were recorded. A partial response was considered as a decrease in the maximal tumor diameter by more than 30% and/or in the hormonal rate by more than 50% at the end of treatment.

RESULTS

The median treatment duration was 6.5 cycles (range 2-24), using a standard regimen for most and combined radiotherapy for six. Twenty-two patients (51.2%) were considered as responders. Silent tumor at diagnosis was associated with a poor response. The median follow-up after the end of treatment was 16 months (0-72). Overall survival was significantly higher among responders (P = 0.002); however, ten patients relapsed 5 months (0-57) after the end of TMZ treatment, five in whom TMZ was reinitiated without success.

DISCUSSION

Patients in our series showed a 51.2% response rate to TMZ, with an improved survival among responders despite frequent relapses. Our study highlights the high variability and lack of standardization of treatment protocols.

How effective is temozolomide for treating pituitary tumours and when should it be used?

Temozolomide (TMZ) has been shown as an effective treatment option in aggressive pituitary adenomas and carcinomas. This review analyses the published case series and demonstrates 42 % of patents show a radiological response and 27 % experience stable disease following TMZ. Prolactinomas and corticotroph tumours respond best to TMZ, showing approximately a 50 % response rate, with non-functioning tumours responding only half as frequently. Other factors that may predict the tumour's TMZ response include MGMT and MSH status, but neither is sufficiently robust to determine treatment decisions. TMZ has an accepted role in treating pituitary carcinoma and adenomas if radiation and surgery have failed to control tumour growth. To use TMZ on the basis of anticipated future aggression, as a primary therapy, or in preference to radiotherapy remains controversial.

Pituitary carcinoma: A case report and discussion of potential value of combined use of Ga-68 DOTATATE and F-18 FDG PET/CT scan to better choose therapy

BACKGROUND

Pituitary carcinoma is extremely rare and carries a very poor prognosis. In most cases, apparently indolent tumors become malignant; however, there are no satisfactory biomarkers for predicting tumor behavior. Thus, scientific advances in the search for new biological markers, diagnostic methods, and therapies are needed to improve the prognosis of these patients.

CASE DESCRIPTION

We report the case of a woman with initial diagnosis of nonfunctioning pituitary adenoma which evolved to carcinoma after 4 years. Diagnosis was confirmed after biopsy of metastatic pulmonary nodules, in which neoplastic cells were immunohistochemically positive for chromogranin, synaptotophysin, prolactin, and growth hormone. Investigation with conventional somatostatin receptor scintigraphy, positron emission tomography-computed tomography (PET-CT) with Ga-68 DOTATATE and F-18 fluorodeoxyglucose (FDG) are showed. During temozolomide therapy, our patient had severe pancytopenia resulting in death from generalized infection despite 10 days of intensive care.

CONCLUSION

The present case of an aggressive pituitary carcinoma rising from a typical adenoma illustrates the importance of developing new prognostic biomarkers in these cases. In addition to demonstrating a serious side effect with the use of temozolomide, our case report suggests that the combined use of Ga-68 DOTATATE and F-18 FDG PET-CT scan may scale somatostatin receptors vs. tumor aggressiveness, therefore, helping to better choose the therapy for aggressive pituitary tumors.

Currently used and investigational drugs for Cushing´s disease

INTRODUCTION

Cushing's disease (CD) is caused by a corticotroph adenoma of the pituitary gland that secretes excess adrenocorticotropic hormone (ACTH) causing increased morbidity and mortality. Surgery is the treatment of choice, but is not always successful. Alternatives include radiotherapy, adrenal surgery, and pharmaceutical therapy. The latter is increasingly gaining momentum due to the recent development of compounds that reduce hypercortisolaemia or its symptoms, acting through different mechanisms. Areas covered: In this article, the authors provide a complete overview of the treatment options for Cushing´s disease, including adrenal-directed, tumor-targeted, and peripheral therapies that are currently used or in development, and discuss their potential advantages and limitations. Expert opinion: Considering the lack of long-term remission in up to half of the patients after surgery, and the delayed response to radiotherapy along with potential side effects, there is a strong need for an effective pharmaceutical treatment. Pasireotide, mifepristone, ketoconazole and metyrapone have been approved by regulatory authorities but their use remains limited due to considerable costs and side effects. Research in this field has focused recently on the improvement of pre-existing drugs and the development of safe new ones. However, few approaches aim at targeting the source of the disease, the ACTH-secreting adenoma.

Role of "old" pharmacological agents in the treatment of Cushing's syndrome

Despite recent advances in the management of endogenous Cushing's syndrome (CS), its treatment remains a challenge. When surgery has been unsuccessful or unfeasible as well in case of recurrence, the "old" pharmacological agents represent an important alternative for both ACTH-dependent and independent hypercortisolism. Especially in the latter, the advent of novel molecules directly targeting ACTH secretion has not outweighed the "old" drugs, which continue to be largely employed and have recently undergone a reappraisal. This review provides a survey of the "old" pharmacological agents in the treatment of CS.

Radiotherapy with concurrent temozolomide for the management of extraneural metastases in pituitary carcinoma

BACKGROUND

Pituitary carcinomas (PC) are uncommon neuroendocrine tumors, accounting for 0.1 % of all pituitary tumors. The diagnosis of PC is based on the presence of metastases from a pituitary adenoma, and not by local invasion or pathological features alone. PC is typically resistant to therapy, with a median overall survival of only 31 months. There is no standard treatment for PC, but maximal safe resection and radiation are performed when possible. Encouraging preliminary data on the use of temozolomide (TMZ)-based therapy has been previously reported.

METHODS

We report the response to therapy and safety of radiation with concurrent temozolomide (RT/TMZ) in 2 adult patients with heavily pretreated PC and extraneural metastases.

RESULTS

Both patients had prior history of pituitary macroadenoma. At the time of diagnosis of PC, Ki-67 % was 24.2 and 10 %, with positive p53 staining in one case. Metastatic sites included lymph nodes, liver and bone. Case-1 received RT/TMZ to the tumor bed in the skull base and to the metastases in the cervical lymph nodes. Case-2 received RT/TMZ to recurrent tumor involving portacaval lymph nodes. Both patients achieved excellent long-term control of the sites of treated extraneural metastases, with no significant acute or delayed toxicity.

CONCLUSIONS

RT/TMZ was safely delivered and might provide sustained control of extraneural metastases in PC. Although this retrospective report has limitations, RT/TMZ can be considered as a therapeutic option for the management of extraneural metastases in PC.

Is there a role for early chemotherapy in the management of pituitary adenomas?

Pituitary adenomas are benign intracranial neoplasms that are frequently well-controlled with standard treatments that include surgical resection, radiotherapy, and agents that modulate hormonal excess. Unfortunately, a subset of patients remains uncontrolled or develops complications from these interventions. For these patients, chemotherapy is an additional treatment option that could improve outcomes. Temozolomide is an oral chemotherapy with a favorable side-effect profile that has shown activity against pituitary adenomas. Its non-overlapping toxicity and ability to induce rapid tumor regression renders it a potentially important adjunctive treatment. In patients with tumors that cannot be optimally addressed with standard treatments, there may be a role for early initiation of temozolomide.