Efficacy and complications of pituitary irradiation

Meta-analysis of mortality in adults with growth hormone deficiency: Does growth hormone replacement therapy really improve mortality rates?

Growth hormone (GH) deficiency (GHD) is one of the most prevalent deficiencies in patients with hypopituitarism and several cohort studies have demonstrated an increased mortality risk in hypopituitary patients with a presumed GHD. The cause of the excess mortality is most likely multifactorial, including the etiology of the hypopituitarism, non-physiological replacement therapies (mostly glucocorticoid), tumor treatment and its side effects as well as untreated GHD. Several years later, other cohort studies that investigated life expectancy in patients with hypopituitarism on GH replacement therapy (GHRT) that showed a normalized mortality. By comparison of the distribution of characteristics of interest between cohorts, we discuss the existing literature to answer the following question: does growth hormone replacement really improve mortality rates in adult patients with hypopituitarism and GHD? We also conducted a meta-analysis of these studies. Since the literature suffers from selection and time bias (improvement of tumor management and other pituitary hormone replacement therapies), there is no high-quality evidence that replacement therapy for GHD really improves mortality. However, the available data does suggest that GHRT plays a significant part in the normalization of the mortality in patients with hypopituitarism.

Risk of second brain tumour after radiotherapy for pituitary adenoma or craniopharyngioma: a retrospective, multicentre, cohort study of 3679 patients with long-term imaging surveillance

BACKGROUND

Radiotherapy is a valuable treatment in the management algorithm of pituitary adenomas and craniopharyngiomas. However, the risk of second brain tumour following radiotherapy is a major concern. We assessed this risk using non-irradiated patients with the same primary pathology and imaging surveillance as controls.

METHODS

In this multicentre, retrospective cohort study, 4292 patients with pituitary adenoma or craniopharyngioma were identified from departmental registries at six adult endocrine centres (Birmingham, Oxford, Leeds, Leicester, and Bristol, UK and Ferrara, Italy). Patients with insufficient clinical data, known genetic predisposition to or history of brain tumour before study entry (n=532), and recipients of proton beam or stereotactic radiotherapy (n=81) were excluded. Data were analysed for 996 patients exposed to 2-dimensional radiotherapy, 3-dimensional conformal radiotherapy, or intensity-modulated radiotherapy, and compared with 2683 controls.

FINDINGS

Over 45 246 patient-years, second brain tumours were reported in 61 patients (seven malignant [five radiotherapy, two controls], 54 benign [25 radiotherapy, 29 controls]). Radiotherapy exposure and older age at pituitary tumour detection were associated with increased risk of second brain tumour. Rate ratio for irradiated patients was 2·18 (95% CI 1·31-3·62, p<0·0001). Cumulative probability of second brain tumour was 4% for the irradiated and 2·1% for the controls at 20 years.

INTERPRETATION

Irradiated adults with pituitary adenoma or craniopharyngioma are at increased risk of second brain tumours, although this risk is considerably lower than previously reported in studies using general population controls with no imaging surveillance. Our data clarify an important clinical question and guide clinicians when counselling patients with pituitary adenoma or craniopharyngioma on the risks and benefits of radiotherapy.

FUNDING

Pfizer.

Endocrine Function after Transsphenoidal Surgery in Patients with Non-Functioning Pituitary Adenomas: A Systematic Review and Meta-Analysis

INTRODUCTION

Transsphenoidal surgery is the current treatment for mass reduction in patients with non-functional pituitary adenomas (NFPAs). The surgical procedure may deteriorate or recover pituitary endocrine function. The aim of this study was to systematically assess the benefits and harms of transsphenoidal surgery on pituitary endocrine function in patients with NFPAs.

METHODS

This systematic review and meta-analysis was registered with PROSPERO (registration No. CRD42020210853). We searched Pubmed and EMBASE for studies reporting on pituitary function before and after transsphenoidal surgery in patients with NFPAs having a minimum follow-up of 1 month. The prespecified primary outcomes were the proportions of patients with improved or deteriorated pituitary function after surgery reported as weighted mean using random effects meta-analysis or in case of considerable heterogeneity, i.e., I2 ≥ 75%, as a range of reported proportions. Subgroup analyses were planned for the primary outcomes on study level.

RESULTS

Of the 6,597 identified records, 24 studies enrolling 3,816 participants were eligible for assessment. Twenty-three studies were judged to have serious or critical risk of bias. The range of proportions of patients with recovery of at least one pituitary axis was between 10.2% and 97.7% (I2 = 93%), while the range of proportions of patients experiencing loss of at least one axis after pituitary surgery was between 0.0% and 36.6% (I2 = 91%). None of the a priori planned subgroup analyses explained the observed heterogeneity associated with deterioration of pituitary function after surgery, and the proportion of patients may be underestimated due to publication bias.

CONCLUSIONS

The current systematic review finds that the endocrine effect of pituitary surgery is unclear both in terms of the chance of recovery and in terms of the risk of pituitary failure and hypopituitarism should be considered only a relative indication for surgery. However, the range of effects does include potentially clinically relevant rates of pituitary recovery calling for more systematic collection of data in future studies.

Pediatric and Adolescent Oncofertility in Male Patients-From Alpha to Omega

This article reviews the latest information about preserving reproductive potential that can offer enhanced prospects for future conception in the pediatric male population with cancer, whose fertility is threatened because of the gonadotoxic effects of chemotherapy and radiation. An estimated 400,000 children and adolescents aged 0–19 years will be diagnosed with cancer each year. Fertility is compromised in one-third of adult male survivors of childhood cancer. We present the latest approaches and techniques for fertility preservation, starting with fertility preservation counselling, a clinical practice guideline used around the world and finishing with recent advances in basic science and translational research. Improving strategies for the maturation of germ cells in vitro combined with new molecular techniques for gene editing could be the next scientific keystone to eradicate genetic diseases such as cancer related mutations in the offspring of cancer survivors.

Cranial irradiation alters neuroinflammation and neural proliferation in the pituitary gland and induces late-onset hormone deficiency

Cranial radiotherapy induces endocrine disorders and reproductive abnormalities, particularly in long-term female cancer survivors, and this might in part be caused by injury to the pituitary gland, but the underlying mechanisms are unknown. The aim of this study was to investigate the influence of cranial irradiation on the pituitary gland and related endocrine function. Female Wistar rat pups on postnatal day 11 were subjected to a single dose of 6 Gy whole-head irradiation, and hormone levels and organ structure in the reproductive system were examined at 20 weeks after irradiation. We found that brain irradiation reduced cell proliferation and induced persistent inflammation in the pituitary gland. The whole transcriptome analysis of the pituitary gland revealed that apoptosis and inflammation-related pathways were up-regulated after irradiation. In addition, irradiation led to significantly decreased levels of the pituitary hormones, growth hormone, adrenocorticotropic hormone, thyroid-stimulating hormone and the reproductive hormones testosterone and progesterone. To conclude, brain radiation induces reduction of pituitary and reproduction-related hormone secretion, this may due to reduced cell proliferation and increased pituitary inflammation after irradiation. Our results thus provide additional insight into the molecular mechanisms underlying complications after head irradiation and contribute to the discovery of preventive and therapeutic strategies related to brain injury following irradiation.

Hyperprolactinaemia

Hyperprolactinaemia is one of the most common problems in clinical endocrinology. It relates with various aetiologies (physiological, pharmacological, pathological), the clarification of which requires careful history taking and clinical assessment. Analytical issues (presence of macroprolactin or of the hook effect) need to be taken into account when interpreting the prolactin values. Medications and sellar/parasellar masses (prolactin secreting or acting through “stalk effect”) are the most common causes of pathological hyperprolactinaemia. Hypogonadism and galactorrhoea are well-recognized manifestations of prolactin excess, although its implications on bone health, metabolism and immune system are also expanding. Treatment mainly aims at restoration and maintenance of normal gonadal function/fertility, and prevention of osteoporosis; further specific management strategies depend on the underlying cause. In this review, we provide an update on the diagnostic and management approaches for the patient with hyperprolactinaemia and on the current data looking at the impact of high prolactin on metabolism, cardiovascular and immune systems.

Bringing Cardiovascular Comorbidities in Acromegaly to an Update. How Should We Diagnose and Manage Them?

Patients with acromegaly frequently develop cardiovascular comorbidities, which significantly affect their morbidity and contribute to an increased all-cause mortality. In this regard, the most frequent complications that these patients may encounter include hypertension, cardiomyopathy, heart valve disease, arrhythmias, atherosclerosis, and coronary artery disease. The specific underlying mechanisms involved in the pathophysiology of these comorbidities are not always fully understood, but uncontrolled GH/IGF-I excess, age, prolonged disease duration, and coexistence of other cardio-vascular risk factors have been identified as significant influencing predisposing factors. It is important that clinicians bear in mind the potential development of cardiovascular comorbidities in acromegalic patients, in order to promptly tackle them, and avoid the progression of cardiac abnormalities. In many cases, this approach may be performed using straightforward screening tools, which will guide us for further diagnosis and management of cardiovascular complications. This article focuses on those cardiovascular comorbidities that are most frequently encountered in acromegalic patients, describes their pathophysiology, and suggests some recommendations for an early and optimal diagnosis, management and treatment.

Pituitary Diseases and Bone

Neuroendocrinology of bone is a new area of research based on the evidence that pituitary hormones may directly modulate bone remodeling and metabolism. Skeletal fragility associated with high risk of fractures is a common complication of several pituitary diseases such as hypopituitarism, Cushing disease, acromegaly, and hyperprolactinemia. As in other forms of secondary osteoporosis, pituitary diseases generally affect bone quality more than bone quantity, and fractures may occur even in the presence of normal or low-normal bone mineral density as measured by dual-energy X-ray absorptiometry, making difficult the prediction of fractures in these clinical settings. Treatment of pituitary hormone excess and deficiency generally improves skeletal health, although some patients remain at high risk of fractures, and treatment with bone-active drugs may become mandatory. The aim of this review is to discuss the physiological, pathophysiological, and clinical insights of bone involvement in pituitary diseases.

Mortality in patients with non-functioning pituitary adenoma

Non-functioning pituitary adenomas (NFA) are benign pituitary neoplasms not associated with clinical evidence of hormonal hypersecretion. A substantial number of patients with NFA have morbidities related to the tumor and possible recurrence(s), as well as to the treatments offered. Studies assessing the long-term mortality of patients with NFA are limited. Based on the published literature of the last two decades, overall, the standardized mortality ratios in this group suggest mortality higher than that of the general population with deaths attributed mainly to circulatory, respiratory and infectious causes. Women seem to have higher mortality ratios, and assessment of time trends suggests improvement over the years. There is no consensus on predictive factors of mortality but those most consistently identified are older age at diagnosis and high doses of glucocorticoid substitution therapy. Well designed and of adequate power studies are needed to establish the significance of factors compromising the survival of patients with NFA and to facilitate improvements in long-term prognosis.

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.

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.

Advances in understanding hypopituitarism

The understanding of hypopituitarism has increased over the last three years. This review provides an overview of the most important recent findings. Most of the recent research in hypopituitarism has focused on genetics. New diagnostic techniques like next-generation sequencing have led to the description of different genetic mutations causative for congenital dysfunction of the pituitary gland while new molecular mechanisms underlying pituitary ontogenesis have also been described. Furthermore, hypopituitarism may occur because of an impairment of the distinctive vascularization of the pituitary gland, especially by disruption of the long vessel connection between the hypothalamus and the pituitary. Controversial findings have been published on post-traumatic hypopituitarism. Moreover, autoimmunity has been discussed in recent years as a possible reason for hypopituitarism. With the use of new drugs such as ipilimumab, hypopituitarism as a side effect of pharmaceuticals has come into focus. Besides new findings on the pathomechanism of hypopituitarism, there are new diagnostic tools in development, such as new growth hormone stimulants that are currently being tested in clinical trials. Moreover, cortisol measurement in scalp hair is a promising tool for monitoring cortisol levels over time.

Cardiovascular comorbidities in acromegaly: an update on their diagnosis and management

Comorbidities related to the cardiovascular system are one of the most prevalent in patients with acromegaly, and contribute to an increased risk of morbidity and all-cause mortality. Specifically, hypertension, cardiomyopathy, heart valve disease, arrhythmias, atherosclerosis, coronary artery disease, and cardiac dysfunction may be frequent findings. Although the underlying physiopathology for each comorbidity may not be fully elucidated, uncontrolled growth hormone/insulin-like growth factor 1 excess, age, prolonged disease duration, and coexistence of other cardio-vascular risk factors are significant influencing variables. A simple diagnostic approach to screen for the presence of these comorbidities may allow prompt treatment and arrest the progression of cardiac abnormalities. In this article, we revise the most prevalent cardiovascular comorbidities and their pathophysiology in acromegalic patients, and we address some recommendations for their prompt diagnosis, management and treatment. Strengths and pitfalls of different diagnostic techniques that are currently being used and how different treatments can affect these complications will be further discussed.

Hormonal Replacement in Hypopituitarism in Adults: An Endocrine Society Clinical Practice Guideline

OBJECTIVE

To formulate clinical practice guidelines for hormonal replacement in hypopituitarism in adults.

PARTICIPANTS

The participants include an Endocrine Society-appointed Task Force of six experts, a methodologist, and a medical writer. The American Association for Clinical Chemistry, the Pituitary Society, and the European Society of Endocrinology co-sponsored this guideline.

EVIDENCE

The Task Force developed this evidence-based guideline using the Grading of Recommendations, Assessment, Development, and Evaluation system to describe the strength of recommendations and the quality of evidence. The Task Force commissioned two systematic reviews and used the best available evidence from other published systematic reviews and individual studies.

CONSENSUS PROCESS

One group meeting, several conference calls, and e-mail communications enabled consensus. Committees and members of the Endocrine Society, the American Association for Clinical Chemistry, the Pituitary Society, and the European Society of Endocrinology reviewed and commented on preliminary drafts of these guidelines.

CONCLUSIONS

Using an evidence-based approach, this guideline addresses important clinical issues regarding the evaluation and management of hypopituitarism in adults, including appropriate biochemical assessments, specific therapeutic decisions to decrease the risk of co-morbidities due to hormonal over-replacement or under-replacement, and managing hypopituitarism during pregnancy, pituitary surgery, and other types of surgeries.

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.

Mortality in patients with non-functioning pituitary adenoma is increased: systematic analysis of 546 cases with long follow-up

OBJECTIVE

Non-functioning pituitary adenomas (NFAs) have a prevalence of 7-22/100,000 people. A significant number of patients suffer from morbidities related to the tumor, possible recurrence(s), and treatments utilized. Our aim was to assess mortality of patients with macroNFA and predictive factors.

DESIGN

Retrospective cohort study in a tertiary referral center in the UK.

METHODS

A total of 546 patients operated for a macroNFA between 1963 and 2011 were studied. Mortality data were retrieved through the National Health Service Central Register and hospital records and recorded as standardized mortality ratio (SMR). Mortality was estimated for the total and various subgroups with clinical follow-up data.

RESULTS

Median follow-up was 8 years (range: 1 month-48.5 years). SMR was 3.6 (95% CI, 2.9-4.5), for those operated before 1990, 4.7 (95% CI, 2.7-7.6) and for those after 1990, 3.5 (95% CI, 2.8-4.4). Main causes of death were cardio/cerebrovascular (33.7%), infections (30.1%), and malignancy (28.9%). Cox regression analysis demonstrated that only age at diagnosis remained an independent predictor of mortality (hazard ratio 1.10; 95% CI, 1.07-1.13, P<0.001), whereas sex, presentation with acute apoplexy, extent of tumor removal, radiotherapy, recurrence, untreated GH deficiency, FSH/LH deficiency, ACTH deficiency, TSH deficiency, and treatment with desmopressin had no impact.

CONCLUSIONS

Despite the improvement of treatments over the last three decades, the mortality of patients with NFAs in our series remains high. Apart from age, factors related with the management/outcome of the tumor are not independent predictors, and pituitary hormone deficits managed with the currently-used substitution protocols do not adversely affect mortality.