Incidence of primary cancers and intracranial tumour recurrences in GH-treated and untreated adult hypopituitary patients: analyses from the Hypopituitary Control and Complications Study

Intracranial germ cell tumors: a view of the endocrinologist

Intracranial germ cell tumors (iGCTs) are rare malignant neoplasms that mainly affect children and adolescents. The incidence, clinical presentation, and prognosis of iGCTs exhibit high heterogeneity. Previous studies have primarily focused on eliminating tumors, reducing tumor recurrence, and improving survival rates, while neglecting the impact of the tumors and their treatment on neuroendocrine function. Throughout the entire course of the disease, neuroendocrine dysfunction may occur and is frequently overlooked by oncologists, neurosurgeons, and radiologists. Endocrinologists, however, are more interested in this issue and have varying priorities at different stages of the disease. From onset to the diagnostic phase, most patients with iGCTs may present with symptoms related to impaired neuroendocrine function, or even experience these symptoms as their first indication of the condition. Particularly, a minority of patients with sellar/suprasellar lesions may exhibit typical imaging features and elevated tumor markers long after the onset of initial symptoms. This can further complicate the diagnosis process. During the peritumor treatment phase, the neuroendocrine function shows dynamic changes and needs to be evaluated dynamically. Once diabetes insipidus and dysfunction of the hypothalamic-pituitary-adrenal and hypothalamic-pituitary-thyroid axes occur, hormone replacement therapy should be administered promptly to ensure successful tumor treatment for the patient. Subsequently, during the long-term management phase after the completion of tumor treatment, the evaluation of growth and development as well as corresponding hormone replacement therapy are the most concerning and complex issues. Thus, this paper reviews the interest of endocrinologists in iGCTs at different stages.

Safety of long-term use of daily and long-acting growth hormone in growth hormone-deficient adults on cancer risk

Daily injections of recombinant human growth hormone (rhGH) have been used in clinical practice for almost four decades as a replacement therapy in adult patients with GH deficiency (GHD). Long-term adherence to daily injections of rhGH is a clinical concern that may result in reduced therapeutic efficacy, and long-acting GH (LAGH) formulations have been developed in an attempt of overcoming this problem. Long-term safety issues of rhGH are the other side of the coin that has been carefully monitored over the years, particularly related to the proliferative actions of GH that could increase the risk of tumor recurrence or induce the development of new benign and malignant tumors. In this review, we present what is currently known about the cancer risk in GHD adults treated with daily rhGH injections and we discuss the major concerns and responses needed from future surveillance studies regarding the safety of LAGH preparations.

Safety of Growth Hormone Replacement Therapy in Childhood-Onset Craniopharyngioma: A Systematic Review and Cohort Study

INTRODUCTION

Survival of childhood-onset craniopharyngioma (cCP) is excellent; however, many survivors suffer from hypothalamic-pituitary dysfunction. Growth hormone replacement therapy (GHRT) is of high importance for linear growth and metabolic outcome. Optimal timing for initiation of GHRT in cCP is on debate because of concerns regarding tumor progression or recurrence.

METHODS

A systematic review and cohort studys were performed for the effect and timing of GHRT on overall mortality, tumor progression/recurrence, and secondary tumors in cCP. Within the cohort, cCP receiving GHRT ≤1 year after diagnosis were compared to those receiving GHRT >1 year after diagnosis.

RESULTS

Evidence of 18 included studies, reporting on 6,603 cCP with GHRT, suggests that GHRT does not increase the risk for overall mortality, progression, or recurrent disease. One study evaluated timing of GHRT and progression/recurrence-free survival and found no increased risk with earlier initiation. One study reported a higher than expected prevalence of secondary intracranial tumors compared to a healthy population, possibly confounded by radiotherapy. In our cohort, 75 of 87 cCP (86.2%) received GHRT for median of 4.9 years [0.0-17.1]. No effect of timing of GHRT was found on mortality, progression/recurrence-free survival, or secondary tumors.

CONCLUSION

Although the quality of the evidence is low, the available evidence suggests no effect of GHRT or its timing on mortality, tumor progression/recurrence, or secondary neoplasms in cCP. These results support early initiation of GHRT in cCP aiming to optimize linear growth and metabolic outcome. Prospective studies are needed to increase the level of evidence upon the optimal timing to start GHRT in cCP patients.

Predictive Factors for Pediatric Craniopharyngioma Recurrence: An Extensive Narrative Review

Despite being classified as benign tumors, craniopharyngiomas (CPs) are associated with significant morbidity and mortality due to their location, growth pattern, and tendency to recur. Two types can be identified depending on age distribution, morphology, and growth pattern, adamantinomatous and papillary. The adamantinomatous CP is one of the most frequently encountered central nervous system tumors in childhood. Our aim was to review the relevant literature to identify clinical, morphological, and immunohistochemical prognostic factors that have been implicated in childhood-onset CP recurrence. Lack of radical surgical removal of the primary tumor by an experienced neurosurgical team and radiotherapy after a subtotal excision has been proven to significantly increase the recurrence rate of CP. Other risk factors that have been consistently recognized in the literature include younger age at diagnosis (especially <5 years), larger tumor size at presentation, cystic appearance, difficult tumor location, and tight adherence to surrounding structures, as well as the histological presence of whorl-like arrays. In addition, several other risk factors have been studied, albeit with conflicting results, especially in the pediatric population. Identifying risk factors for CP recurrence is of utmost importance for the successful management of these patients in order to ultimately ensure the best prognosis.

Long-Term Safety of Growth Hormone Deficiency Treatment in Cancer and Sellar Tumors Adult Survivors: Is There a Role of GH Therapy on the Neoplastic Risk?

Experimental studies support the hypothesis that GH/IGF-1 status may influence neoplastic tissue growth. Epidemiological studies suggest a link between GH/IGF-1 status and cancer risk. However, several studies regarding GH replacement safety in childhood cancer survivors do not show a prevalence excess of de novo cancers, and several reports on children and adults treated with GH have not shown an increase in observed cancer risk in these patients. The aim of this review is to provide an at-a-glance overview and the state of the art of long-term effects of GH replacement on neoplastic risk in adults with growth hormone deficiency who have survived cancer and sellar tumors.

Long-term Safety of Growth Hormone in Adults With Growth Hormone Deficiency: Overview of 15 809 GH-Treated Patients

CONTEXT

Data on long-term safety of growth hormone (GH) replacement in adults with GH deficiency (GHD) are needed.

OBJECTIVE

We aimed to evaluate the safety of GH in the full KIMS (Pfizer International Metabolic Database) cohort.

METHODS

The worldwide, observational KIMS study included adults and adolescents with confirmed GHD. Patients were treated with GH (Genotropin [somatropin]; Pfizer, NY) and followed through routine clinical practice. Adverse events (AEs) and clinical characteristics (eg, lipid profile, glucose) were collected.

RESULTS

A cohort of 15 809 GH-treated patients were analyzed (mean follow-up of 5.3 years). AEs were reported in 51.2% of patients (treatment-related in 18.8%). Crude AE rate was higher in patients who were older, had GHD due to pituitary/hypothalamic tumors, or adult-onset GHD. AE rate analysis adjusted for age, gender, etiology, and follow-up time showed no correlation with GH dose. A total of 606 deaths (3.8%) were reported (146 by neoplasms, 71 by cardiac/vascular disorders, 48 by cerebrovascular disorders). Overall, de novo cancer incidence was comparable to that in the general population (standard incidence ratio 0.92; 95% CI, 0.83-1.01). De novo cancer risk was significantly lower in patients with idiopathic/congenital GHD (0.64; 0.43-0.91), but similar in those with pituitary/hypothalamic tumors or other etiologies versus the general population. Neither adult-onset nor childhood-onset GHD was associated with increased de novo cancer risks. Neutral effects were observed in lipids/fasting blood glucose levels.

CONCLUSION

These final KIMS cohort data support the safety of long-term GH replacement in adults with GHD as prescribed in routine clinical practice.

Safety of growth hormone replacement in survivors of cancer and intracranial and pituitary tumours: a consensus statement

Growth hormone (GH) has been used for over 35 years, and its safety and efficacy has been studied extensively. Experimental studies showing the permissive role of GH/insulin-like growth factor 1 (IGF-I) in carcinogenesis have raised concerns regarding the safety of GH replacement in children and adults who have received treatment for cancer and those with intracranial and pituitary tumours. A consensus statement was produced to guide decision-making on GH replacement in children and adult survivors of cancer, in those treated for intracranial and pituitary tumours and in patients with increased cancer risk. With the support of the European Society of Endocrinology, the Growth Hormone Research Society convened a Workshop, where 55 international key opinion leaders representing 10 professional societies were invited to participate. This consensus statement utilized: (1) a critical review paper produced before the Workshop, (2) five plenary talks, (3) evidence-based comments from four breakout groups, and (4) discussions during report-back sessions. Current evidence reviewed from the proceedings from the Workshop does not support an association between GH replacement and primary tumour or cancer recurrence. The effect of GH replacement on secondary neoplasia risk is minor compared to host- and tumour treatment-related factors. There is no evidence for an association between GH replacement and increased mortality from cancer amongst GH-deficient childhood cancer survivors. Patients with pituitary tumour or craniopharyngioma remnants receiving GH replacement do not need to be treated or monitored differently than those not receiving GH. GH replacement might be considered in GH-deficient adult cancer survivors in remission after careful individual risk/benefit analysis. In children with cancer predisposition syndromes, GH treatment is generally contraindicated but may be considered cautiously in select patients.

Growth Hormone replacement therapy in pediatric brain tumor survivors

Brain tumors are the most frequent type of solid neoplasms in children with a recognized 5-year survival rate between 57 and 65%. The survival rate progressively increased in the last few years, due to the improvements in their treatment based on chemotherapy, radiotherapy, and surgery. At the same time, at long term follow-up, clinicians should carefully evaluate comorbidities and long term sequelae secondary to the disease and its treatment. Growth Hormone Deficiency (GHD) is an endocrinopathy commonly found among pediatric cancer survivors, with a negative effect on the child's final height and entire metabolism. GH replacement therapy (GHRT), with a synthetic hormone analog, may improve the growth rate and finally adult height, ameliorating the quality of life after cancer treatment. However, in clinical practice, GHRT is adopted with caution for fear of cancer recurrence or the onset of second malignancies. In our review, we perform a focus on the GH structure and function, comparing benefits and risks of GHRT, derived from the analysis of the data currently available in the literature.

Pituitary tumors and the risk of other malignancies: is the relationship coincidental or causal?

Pituitary adenomas are benign neoplasms of the pituitary. The most prevalent are prolactinomas and non-functioning pituitary adenomas, followed by growth hormone- and ACTH-secreting adenomas. Most pituitary adenomas seem to be sporadic and their persistent growth is very atypical. No molecular markers predict their behavior. The occurrence of pituitary adenomas and malignancies in the same patient can be either pure coincidence or caused by shared underlying genetic susceptibility involved in tumorigenesis. Detailed family history on cancers/tumors in the first, second and third generation of family members on each side of the family has been reported in a few studies. They found an association of pituitary tumors with positive family history for breast, lung and colorectal cancer. We have reported that in about 50% of patients with pituitary adenomas, an association with positive family history for cancer has been found independent of secretory phenotype (acromegaly, prolactinoma, Cushing's disease or non-functioning pituitary adenomas). We also found earlier onset of pituitary tumors (younger age at diagnosis of pituitary tumors) in patients with a strong family history of cancer. In our recent unpublished series of 1300 patients with pituitary adenomas, 6.8% of patients were diagnosed with malignancy. The latency period between the diagnosis of pituitary adenoma and cancer was variable, and in 33% of patients, it was longer than 5 years. Besides the inherited trophic mechanisms (shared underlying genetic variants), the potential influence of shared complex epigenetic influences (environmental and behavioral factors - obesity, smoking, alcohol intake and insulin resistance) is discussed. Further studies are needed to better understand if patients with pituitary adenomas are at increased risk for cancer.

The Proteomic Signature of Recombinant Growth Hormone in Recreational Athletes

OBJECTIVE

Administration of human growth hormone (hGH) is prohibited in competitive sport and its detection in an athlete's sample triggers an adverse analytical finding. However, the biological processes that are modulated by recombinant hGH are not well characterized and associated blood serum proteins may constitute new biomarkers for hGH misuse.

METHODS

Thirty-five recreational athletes were enrolled in a study to investigate the time- and dose-dependent response of serum protein levels to recombinant hGH administration. Participants were randomly assigned to 4 groups, receiving 1 of 3 different doses of recombinant hGH or a placebo. Bio samples were collected at 22 time points over a period of 13 weeks, starting 4 weeks before treatment, during 3 weeks of treatment, and at 6 weeks' follow-up. A total of 749 serum samples were analyzed for 1305 protein markers using the SOMAscan proteomics platform.

RESULTS

We identified 66 proteins that significantly associated with recombinant hGH administration and dosage, including well known hGH targets, such as IGF1, but also previously unknown hGH-related proteins (eg, protease inhibitors, WFIKKN1, and chemokines, CCL2). Network analysis revealed changes in specific biological pathways, mainly related to the immune system and glucose metabolism.

CONCLUSION

Our analysis suggests that hGH administration affects biological processes more strongly than previously acknowledged. Some of the proteins were dysregulated even after hGH treatment and could potentially be developed into biomarkers for hGH misuse. Moreover, our findings suggest new roles for hGH-associated proteins in the etiology of hGH-related diseases and may indicate new risks that may be associated with hGH misuse.

Safety of growth hormone (GH) treatment in GH deficient children and adults treated for cancer and non-malignant intracranial tumors-a review of research and clinical practice

Individuals surviving cancer and brain tumors may experience growth hormone (GH) deficiency as a result of tumor growth, surgical resection and/or radiotherapy involving the hypothalamic-pituitary region. Given the pro-mitogenic and anti-apoptotic properties of GH and insulin-like growth factor-I, the safety of GH replacement in this population has raised hypothetical safety concerns that have been debated for decades. Data from multicenter studies with extended follow-up have generally not found significant associations between GH replacement and cancer recurrence or mortality from cancer among childhood cancer survivors. Potential associations with secondary neoplasms, especially solid tumors, have been reported, although this risk appears to decline with longer follow-up. Data from survivors of pediatric or adult cancers who are treated with GH during adulthood are scarce, and the risk versus benefit profile of GH replacement of this population remains unclear. Studies pertaining to the safety of GH replacement in individuals treated for nonmalignant brain tumors, including craniopharyngioma and non-functioning pituitary adenoma, have generally been reassuring with regards to the risk of tumor recurrence. The present review offers a summary of the most current medical literature regarding GH treatment of patients who have survived cancer and brain tumors, with the emphasis on areas where active research is required and where consensus on clinical practice is lacking.

Safety of current recombinant human growth hormone treatments for adults with growth hormone deficiency and unmet needs

INTRODUCTION

Growth hormone (GH) deficiency (GHD) in adults is characterized by abnormal body composition, unfavorable cardiovascular risk factors, and poor quality of life. The diagnosis is made within appropriate clinical settings and according to established guidelines. Numerous studies have shown that GH treatment improves body composition, cardiovascular risk factors, physical capacity, and quality of life while issues on safety, in particular long-term safety, remain.

AREAS COVERED

Short- and long-term safety of GH replacement in adults with GHD.

EXPERT OPINION

Adults with GHD are an inhomogeneous group of patients and GH replacement requires individual considerations. Most adverse effects are mild and transient and related to fluid retention and GH dose. In patients without comorbidities long-term GH treatment is safe and development of diabetes, cardiovascular disease, or tumors are not increased. Furthermore, mortality is not increased. Patients with risk factors should be identified before GH treatment is initiated and an optimal balance between benefit and risk established. Studies with sufficient duration and power to identify the development of cardiovascular diseases and cancers are still awaited. Effective management of comorbidities can be expected to decrease morbidity and mortality and improve quality of life. Studies with long-acting GH formulations are ongoing and available data indicate similar effects and short-time safety.

GH deficiency in cancer survivors in the transition age: diagnosis and therapy

BACKGROUND

Survival rates among childhood cancer survivors (CCSs) have significantly risen in the last 40 years due to substantial improvements in treatment protocols. However, this improvement has brought with it serious late effects that frequently involve the endocrine system. Of the endocrine disorders, GH deficiency (GHD) is the most common among CCSs as a consequence of a history of cancers, surgery, and/or radiotherapy involving the hypothalamo-pituitary region.

METHODS

A comprehensive search of English language articles regardless of age was conducted in the MEDLINE database between December 2018 and October 2019. We selected all studies on GH therapy in CCSs during the transition age regarding the most challenging topics: when to retest; which diagnostic tests and cut-offs to use; when to start GH replacement therapy (GHRT); what GH dose to use; safety; quality of life, compliance and adherence to GHRT; interactions between GH and other hormonal replacement treatments.

RESULTS

In the present review, we provide an overview of the current clinical management of challenges in GHD in cancer survivors in the transition age.

CONCLUSIONS

Endocrine dysfunction among CCSs has a high prevalence in the transition age and increase with time. Many endocrine disorders, including GHD, are often not diagnosed or under-diagnosed, probably due to the lack of specialized centers for the long-term follow-up. Therefore, it is crucial that transition specialized clinics should be increased in terms of number and specific skills in order to manage endocrine disorders in adolescence, a delicate and complex period of life. A multidisciplinary approach, also including psychological counseling, is essential in the follow-up and management of these patients in order to minimize their disabilities and maximize their quality of life.

Clinical experience of growth hormone replacement for pediatric intracranial germ cell tumor

PURPOSE

Intracranial germ cell tumors (IGCTs) account for 8-15% of brain tumors in children in Eastern Asia and typically occur at the age of puberty. Recently, adjuvant therapy has been modified to ameliorate post-treatment complications such as cognitive dysfunction, in patients with IGCT. However, endocrine problems remain to be resolved. There is reluctance to use growth hormone (GH) at an early stage after treatment for IGCT because of the risk of tumor recurrence; however, GH replacement must be administered before the onset of puberty in children with short stature. There is little guidance on this issue due to a lack of literature on the risks of GH replacement therapy in patients with IGCT. This study aimed to evaluate the safety of GH replacement.

METHODS

In this retrospective study, 6 patients with IGCT who were under the age of 18 years when they started GH replacement therapy were reviewed. Histopathological analysis and/or analysis of tumor markers was used to confirm a diagnosis.

RESULTS

All six cases who underwent GH replacement therapy showed no recurrence. GH replacement therapy was administered in 5 patients for short stature and all achieved a height within ± 2.0 standard deviation.

CONCLUSION

GH replacement for children with IGCT was safe in our case series. Placental alkaline phosphatase levels in cerebrospinal fluid can be used to facilitate the decision on when to initiate GH replacement.

Long-Acting Growth Hormone Preparations - Current Status and Future Considerations

CONTEXT

Long-acting GH (LAGH) preparations are currently being developed in an attempt to improve adherence. The profile of GH action following administration of LAGH raises practical questions about clinical monitoring and long-term safety and efficacy of these new therapeutic agents.

METHODS

Recent literature and meeting proceedings regarding LAGH preparations are reviewed.

RESULTS

Multiple LAGH preparations are currently at various stages of development, allowing for decreased GH injection frequency from daily to weekly, biweekly, or monthly. Following administration of LAGH, the serum peak and trough GH and IGF-I levels vary depending upon the mechanism used to prolong GH action. Randomized, controlled clinical trials of some LAGH preparations have reported non-inferiority compared with daily recombinant human GH (rhGH) for improved growth velocity and body composition in children and adults with GH deficiency (GHD), respectively. No significant LAGH-related adverse events have been reported during short-term therapy.

CONCLUSION

Multiple LAGH preparations are proceeding through clinical development with some showing promising evidence of short-term clinical efficacy and safety in children and adults with GHD. The relationship of transient elevations of GH and IGF-I following administration of LAGH to efficacy and safety remain to be elucidated. For LAGH to replace daily rhGH in the treatment of individuals with GHD, a number of practical questions need to be addressed including methods of dose adjustment, timing of monitoring of IGF-I, safety, efficacy, and cost-effectiveness. Long-term surveillance of efficacy and safety of LAGH preparations will be needed to answer these clinically relevant questions.

OFF-LABEL USE AND MISUSE OF TESTOSTERONE, GROWTH HORMONE, THYROID HORMONE, AND ADRENAL SUPPLEMENTS: RISKS AND COSTS OF A GROWING PROBLEM

Over the past few decades, there has been an unprecedented rise in off-label use and misuse of testosterone, growth hormone, thyroid hormone, and adrenal supplements. Testosterone therapy is often promoted to men for the treatment of low energy, lower libido, erectile dysfunction, and other symptoms. Growth hormone is used in attempts to improve athletic performance in athletes and to attenuate aging in older adults. Thyroid hormone and/or thyroid supplements or boosters are taken to treat fatigue, obesity, depression, cognitive impairment, impaired physical performance, and infertility. Adrenal supplements are used to treat common nonspecific symptoms due to "adrenal fatigue," an entity that has not been recognized as a legitimate medical diagnosis. Several factors have contributed to the surge in off-label use and misuse of these hormones and supplements: direct-to-consumer advertising, websites claiming to provide legitimate medical information, and for-profit facilities promoting therapies for men's health and anti-aging. The off-label use and misuse of hormones and supplements in individuals without an established endocrine diagnosis carries known and unknown risks. For example, the risks of growth hormone abuse in athletes and older adults are unknown due to a paucity of studies and because those who abuse this hormone often take supraphysiologic doses in sporadic intervals. In addition to the health risks, off-label use of these hormones and supplements generates billions of dollars of unnecessary costs to patients and to the overall health-care system. It is important that patients honestly disclose to their providers off-label hormone use, as it may affect their health and treatment plan. General medical practitioners and adult endocrinologists should be able to begin a discussion with their patients regarding the unfavorable balance between the risks and benefits associated with off-label use of testosterone, growth hormone, thyroid hormone, and adrenal supplements. Abbreviations: DHEA = dehydroepiandrosterone; FDA = U.S. Food and Drug Administration; GH = growth hormone; IGF-1 = insulin-like growth factor 1; LT3 = L-triiodothyronine; LT4 = levothyroxine; T3 = total triiodothyronine; T4 = thyroxine; TSH = thyroid-stimulating hormone.

Growth hormone replacement in adults: Real-world data from two large studies in US and Europe

OBJECTIVE

This report describes the effectiveness and safety of growth hormone replacement in 3180 adult patients with growth hormone deficiency followed-up for 0.0-12.2 years in two completed, complementary, non-interventional, multicentre studies, NordiNet® International Outcome Study (IOS) (NCT00960128) and the American Norditropin® Studies: Web-Enabled Research (ANSWER) Program (NCT01009905).

DESIGN

In both studies, Norditropin® (somatropin; Novo Nordisk A/S, Denmark) was administered at the discretion of the treating physician and according to routine practice. We present data on baseline characteristics, growth hormone dose, safety data and change from baseline in waist circumference, body mass index and bioimpedance (NordiNet® IOS only).

RESULTS

Mean (SD) baseline characteristics (effectiveness analysis set) in NordiNet® IOS (n = 971) and ANSWER (n = 304): females, 45%; 69%; mean growth hormone dose (mg/day) (female, 0.338 [0.177]; male, 0.289 [0.157]); (female, 0.501 [0.313]; male, 0.505 [0.351]). Most patients had BMI ≥25 kg/m². Median (P10,P90) exposure (females, 3.5 [0.42,11.0]; 1.6 [3.2; 0.3,8.6]; males, 4.1 [0.33,10.8]; 2.3 [2.9; 0.0,7.5] years). Mean (SD) change from baseline for waist circumference (-0.46 [6.38] cm [n = 403], BMI (0.30 [3.30] kg/m² [n = 857]) and bioimpedance (-17.4 (59.19) ohm [n = 239]) were associated with growth hormone dose (waist/bioimpedance) and duration of follow-up (BMI/bioimpedance). No new safety signals were observed among patients in the full analysis set (NordiNet® IOS, n = 2321; ANSWER, n = 859).

CONCLUSIONS

Long-term growth hormone replacement is associated with an improvement in body composition. The accumulated data from >10 years of follow-up support the long-term effectiveness and safety of growth hormone replacement as prescribed in clinical practice.

Adult growth hormone deficiency: clinical advances and approaches to improve adherence

Introduction: There have been significant clinical advances in the understanding of the diagnosis and benefits of long-term recombinant human growth hormone (rhGH) replacement in adults with GH deficiency (GHD) since its approval in 1996 by the United States Food and Drug Administration.Areas covered: We searched PubMed, Medline, CINAHL, EMBASE and PsychInfo databases between January 2000 and June 2019 for published studies evaluating adults with GHD. We reviewed the data of the oral macimorelin test compared to the GHRH plus arginine and the insulin tolerance tests that led to its approval by the United States FDA and European Medicines Agency for adult diagnostic testing. We summarize the clinical advances of long-term benefits of rhGH therapy and the potential effects of GH receptor polymorphisms on individual treatment responsiveness. We identify that non-adherence and discontinuation rates are high and recommend strategies to support patients to improve adherence. We also provide an overview of several long-acting GH (LAGH) preparations currently under development and their potential role in improving treatment adherence.Expert opinion: This article summarizes recent clinical advances in rhGH replacement therapy, the biological and molecular aspects that may influence rhGH action, and offers practical strategies to enhance adherence in adults with GHD.

Long-Term Endocrine and Metabolic Consequences of Cancer Treatment: A Systematic Review

The number of patients surviving ≥5 years after initial cancer diagnosis has significantly increased during the last decades due to considerable improvements in the treatment of many cancer entities. A negative consequence of this is that the emergence of long-term sequelae and endocrine disorders account for a high proportion of these. These late effects can occur decades after cancer treatment and affect up to 50% of childhood cancer survivors. Multiple predisposing factors for endocrine late effects have been identified, including radiation, sex, and age at the time of diagnosis. A systematic literature search has been conducted using the PubMed database to offer a detailed overview of the spectrum of late endocrine disorders following oncological treatment. Most data are based on late effects of treatment in former childhood cancer patients for whom specific guidelines and recommendations already exist, whereas current knowledge concerning late effects in adult-onset cancer survivors is much less clear. Endocrine sequelae of cancer therapy include functional alterations in hypothalamic-pituitary, thyroid, parathyroid, adrenal, and gonadal regulation as well as bone and metabolic complications. Surgery, radiotherapy, chemotherapy, and immunotherapy all contribute to these sequelae. Following irradiation, endocrine organs such as the thyroid are also at risk for subsequent malignancies. Although diagnosis and management of functional and neoplastic long-term consequences of cancer therapy are comparable to other causes of endocrine disorders, cancer survivors need individually structured follow-up care in specialized surveillance centers to improve care for this rapidly growing group of patients.

GH Therapy in Childhood Cancer Survivors: A Systematic Review and Meta-Analysis

BACKGROUND

GH deficiency (GHD) is common among childhood cancer survivors (CCSs) with history of tumors, surgery, and/or radiotherapy involving the hypothalamus-pituitary region. We aimed to evaluate the effects of GH therapy (GHT) in CCSs on adult height, risk of diabetes mellitus, abnormal lipids, metabolic syndrome, quality of life, secondary tumors, and disease recurrence.

METHODS

We searched multiple databases for randomized and observational studies. Pairs of reviewers independently selected studies and collected data. Random effects meta-analysis was used to pool outcomes across the studies.

RESULTS

We included 29 observational studies at moderate to high risk of bias. Sixteen studies compared CCSs on GHT with those not on GHT (512 patients, GH dose: 0.3 to 0.9 IU/kg/week). GHT was significantly associated with height gain [standard deviation score, 0.61; 95% CI, 0.08 to 1.13] and was not significantly associated with the occurrence of secondary tumors [odds ratio (OR), 1.10; 95% CI, 0.72 to 1.67] or tumor recurrence (OR, 0.57; 95% CI, 0.31 to 1.02). Thirteen studies compared CCSs on GHT with normal age- or sex-matched controls or controls with idiopathic GHD or short stature. GHT was associated with either improved or unchanged risk of diabetes, lipid profiles, and metabolic syndrome. GHT was associated with improvements in quality of life.

CONCLUSION

CCSs treated with GHT gain height compared with the untreated controls. GHT may improve lipid profiles and quality of life and does not appear to increase the risk of diabetes or the development of secondary tumors, although close monitoring for such complications remains warranted due to uncertainty in the current evidence.

Long-term safety of growth hormone-A combined registry analysis

OBJECTIVES

Preliminary data from the French cohort of the Safety and Appropriateness of Growth hormone treatments in Europe (SAGhE) study raised concerns regarding the safety of recombinant human GH, suggesting that GH may increase mortality and incidence of stroke in patients treated during childhood for GH deficiency or short stature. We evaluated published safety data, focusing on mortality, neoplasms, cerebrovascular events and diabetes across a number of large-scale pharmaceutical company GH registries.

DESIGN

A literature review was conducted using PubMed, EMBASE and Google Scholar to identify all relevant safety data from manufacturers' GH registries published between 1988 and April 2016. Results were hand-sorted to exclude nonrelevant publications; bibliographic references from retrieved articles were evaluated for any additional references.

RESULTS

The published data do not support an increased risk of mortality in children or adults treated with GH. There was no evidence of an increased risk of stroke, new malignancy, leukaemia, nonleukaemic extracranial tumours or recurrence of intracranial malignancy in patients without risk factors. The risk of a second neoplasm is increased, particularly if patients have received radiation therapy for a central nervous system tumour. There may be an increased risk of type 2 diabetes in GH-treated patients, but this appears to be confined to those with pre-existing risk factors.

CONCLUSIONS

Patients with risk factors for malignancy or type 2 diabetes should be treated with caution and monitored during follow-up, but current published data provide reassurance on the long-term safety profile of GH in patients receiving GH treatment.

Treatment with Growth Hormone for Adults with Growth Hormone Deficiency Syndrome: Benefits and Risks

Pharmacological treatment of growth hormone deficiency (GHD) in adults began in clinical practice more than 20 years ago. Since then, a great volume of experience has been accumulated on its effects on the symptoms and biochemical alterations that characterize this hormonal deficiency. The effects on body composition, muscle mass and strength, exercise capacity, glucose and lipid profile, bone metabolism, and quality of life have been fully demonstrated. The advance of knowledge has also taken place in the biological and molecular aspects of the action of this hormone in patients who have completed longitudinal growth. In recent years, several epidemiological studies have reported interesting information about the long-term effects of GH replacement therapy in regard to the possible induction of neoplasms and the potential development of diabetes. In addition, GH hormone receptor polymorphism could potentially influence GH therapy. Long-acting GH are under development to create a more convenient GH dosing profile, while retaining the excellent safety, efficacy, and tolerability of daily GH. In this article we compile the most recent data of GH replacement therapy in adults, as well as the molecular aspects that may condition a different sensitivity to this treatment.

New Neoplasm During GH Replacement in Adults With Pituitary Deficiency Following Malignancy: A KIMS Analysis

CONTEXT

Data on the association between growth hormone (GH) replacement in patients with GH deficiency (GHD) after malignancies and new neoplasms show conflicting results.

OBJECTIVE

To clarify the incidence of new malignant neoplasm in childhood-onset (CO) and adult-onset (AO) adult cancer survivors (CSs).

DESIGN

Retrospective comparison of CO-CS and AO-CS with CO idiopathic GHD (IGHD) and AO nonfunctioning pituitary adenoma (NFPA) patients and with the general population [standardized incidence ratio (SIR)].

SETTING

Data from the Pfizer International Metabolic Database study (KIMS).

PATIENTS

CO-CS [n = 349; 50.4% females; mean baseline (MBL) IGF-I standard deviation score (SDS), -2.4], IGHD (n = 619; 35.7% females; MBL IGF-I SDS, -3.4), AO-CS (n = 174; 42.5% females; MBL IGF-I SDS, -1.4), and NFPA (n = 2449; 38.1% females; MBL IGF-I SDS, -1.0).

MAIN OUTCOME MEASURES

SIRs of malignant neoplasms.

RESULTS

After a median follow-up of 5.9 years (2192 patient-years), 15 CO-CS (4.3%) had developed 16 new neoplasms. The SIR was 10.4 [95% confidence interval (CI), 5.9 to 16.9] and 6.5 (95% CI, 3.0 to 12.4) after exclusion of seven patients with skin cancers. In IGHD, three malignant neoplasms (0.5%) were observed after a median follow-up of 5.4 years (3908 patient-years; SIR, 0.47; 95% CI, 0.09 to 1.37). New malignant neoplasms occurred in three AO-CS (1.7%; SIR, 1.1; 95% CI, 0.2 to 3.2) and 146 NFPA patients (153 cases, 6.0%; SIR, 1.1; 95% CI, 0.9 to 1.2) after a median follow-up of 4.9 (1024 patient-years) and 5.6 years (15,215 patient-years).

CONCLUSIONS

The risk of second malignant neoplasms was increased in CO-CS but not in AO-CS, which illustrates the need to closely follow patients on GH replacement because of a prior malignancy.

Gender-, age- and time-dependent dosing of growth hormone in adults - real-world data from a decade of clinical practice in Germany

We evaluated treatment patterns and gender-dependent dosing of growth hormone (GH) substitution in adults with GH deficiency (AGHD). Data on GH dose were collected (2003-2013) from 509 GH-treated patients (mean age: 48.9 years; 47% female) enroled in the observational German NordiWin study (NCT01543880). The impact of gender, age, treatment duration and calendar year on GH treatment patterns was evaluated by multiple regression analysis. Mean (SD) baseline GH dose (mg/day) was similar between females (0.25 [0.19] and males (0.24 [0.15]), but increased with treatment duration (at year 10, 0.55 [0.48] and 0.31 [0.09] in females and males, respectively), reflecting patient dose titration. GH dose increased more in females than males during treatment; this was statistically significant in years 2-6 (p < 0.05). Over the 10-year study period, a time trend of an overall estimated GH dose increase by 0.06 mg/day (females) and decrease by 0.07 mg/day (males) was shown; this interaction of gender and calendar year was significant (p < 0.0001). In both genders, overall GH dose decreased with increasing age (p < 0.0001). Our study confirms that females and younger patients require higher GH doses compared with males and older patients.

Incidence of malignant tumours in patients with a non-functioning pituitary adenoma

Whether patients with non-functioning pituitary adenoma (NFPA) are at increased risk of developing malignant tumours has been sparsely studied and is a matter of debate. In this study, we have investigated the incidence of malignant tumours in a large and unselected group of patients with NFPA. The study was nationwide and included all patients diagnosed with NFPA between 1987 and 2011 (n = 2795) in Sweden, identified in the National Patient Register. Malignant tumours, occurring after the NFPA diagnosis, were identified in the Swedish Cancer Register between 1987 and 2014. Standardised incidence ratios (SIRs) for malignant tumours with 95% confidence intervals (CI) were calculated using the Swedish population as reference. In total, 448 malignant tumours were detected in 386 patients with NFPA, as compared to 368 expected malignancies in the general population (SIR 1.22 (95% CI 1.11-1.33)). The incidence of neoplasms of the brain was increased (SIR 5.83 (95% CI 4.03-8.14)). When analysing the total incidence of malignancies excluding neoplasms of the brain, the overall SIR was still increased (SIR 1.14 (95% CI 1.03-1.26)). The incidence of malignant neoplasm of skin other than malignant melanoma (SIR 1.99 (95% CI 1.55-2.52)) and malignant melanoma (SIR 1.62 (95% CI 1.04-2.38)) were increased, whereas the incidence of breast cancer (SIR 0.65 (95% CI 0.42-0.97)) was decreased. The incidence of other types of malignancies did not differ significantly from the expected incidence in the general population. In conclusion, patients with NFPA have an increased overall risk of developing malignancies. To what extent these findings are due to more frequent medical surveillance, genetic predisposition or endocrine changes, remains unknown.

Management of GH treatment in adult GH deficiency

Growth hormone (GH) replacement therapy in adults with GH deficiency is still a challenge for the clinical endocrinologist and its implementation has still numerous difficulties and uncertainties. The decision to treat GH deficient adults requires a thoughtful and individualized evaluation of risks and benefits. Benefits have been found in body composition, bone health, cardiovascular risk factors, and quality of life. However, evidences for a reduction in cardiovascular events and mortality are still lacking, and treatment costs remain high. It is advisable to start treatment with low doses of GH, the goals being an appropriate clinical response, an avoidance of side effects, and IGF-I levels in the age-adjusted reference range. Although treatment appears to be overall safe, certain areas continue to require long-term surveillance, such as risks of glucose intolerance, pituitary/hypothalamic tumor recurrence, and cancer.

Controversies in the risk of neoplasia in GH deficiency

Growth hormone (GH) replacement in GH deficient (GHD) children secures normal linear growth, while in GHD adults it improves metabolic status, body composition and quality of life. Safety of GH treatment is an important issue in particular concerning the controversy of potential cancer risk. Unlike in congenital IGF-1 deficiency, there is no complete protection against cancer in GHD patients. Important modifiable risk factors in GHD patients are obesity, insulin resistance, sedentary behavior, circadian rhythm disruption, chronic low grade inflammation and concomitant sex hormone replacement. Age, family history, hereditary cancer predisposition syndromes or cranial irradiation may present non-modifiable risk factors. Quantifying the risk of cancer in relation to GH therapy in adult GHD patients is complex. There is evidence that links GH to cancer occurrence or promotion, but the evidence is progressively weaker when moving from in vitro studies to in vivo animal studies to epidemiological studies and finally to studies on GH treated patients. GH-IGF inhibition in experimental animals leads to decreased cancer incidence and progression. Epidemiological studies suggest an association of high normal circulating IGF-1 or GH to cancer incidence in general population. Data regarding cancer incidence in acromegaly are inconsistent but thyroid and colorectal neoplasias are the main source of concern. Replacement therapy with rhGH for GHD is generally safe. Overall the rate of de novo cancers was not increased in studies of GH-treated GHD patients. Additional caution is mandated in patients with history of cancer, strong family history of cancer and with advancing age. Childhood cancer survivors may be at increased risk for secondary neoplasms compared with general population. In this subgroup GH therapy should be used cautiously and with respect to other risk factors (cranial irradiation etc). We believe that the benefits of GH therapy against the morbidity of untreated GH deficiency outweigh the theoretical cancer risk. Proper monitoring of GH treatment with diligent cancer surveillance remains essential.

GH deficiency in adult survivors of childhood cancer

Childhood cancer survivors (CCS) are a fast growing population, but late adverse effects of cancer therapies are not rare. In CCS treated with cranial radiotherapy, growth hormone deficiency (GHD) is a well-known occurrence and the potential impact of GH replacement therapy on the global outcome of CCS is under continuous evaluation. In the present review, we discuss advantages and disadvantages of GH replacement therapy in survivors of pediatric malignancies, taking into consideration the different reasons for treating GHD during childhood or adult life. It is doubtless that GH treatment is advisable to obtain a normal growth in pediatric patients. As far as the beginning/continuation of the replacement therapy in adult age is concerned, contrasting results have been reported in literature. The suggestion is that the decision to treat adult CCS should be taken after careful evaluation of each patient's clinical history and of the potential side effects, in agreement with the patients.

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.

[Endocrine consequences in young adult survivors of childhood cancer treatment]

Endocrine complications (particularly gonadal, hypothalamic-pituitary and metabolic) of childhood cancer treatments are common in young adults. Gonadal damage may be the result of chemotherapy or radiotherapy. Fertility preservation must be systematically proposed before initiation of gonadotoxic treatment if only the child is eligible. Hypothalamic-pituitary deficiency is common after brain or total-body irradiation, the somatotropic axis is the most sensitive to irradiation. Pituitary deficiency screening must be repeated since this endocrine consequence can occur many years after treatment. Hormone replacement must be prudent particularly in case of treatment with growth hormone or steroids. Metabolic syndrome, diabetes and cardiovascular damage resulting from cancer treatments contribute to the increase of morbidity and mortality in this population and should be screened routinely even if the patient is asymptomatic. The multidisciplinary management of these adults must be organized and the role of the endocrinologist is now well established.

Is there an effect of ghrelin/ghrelin analogs on cancer? A systematic review

Ghrelin is a hormone with multiple physiologic functions, including promotion of growth hormone release, stimulation of appetite and regulation of energy homeostasis. Treatment with ghrelin/ghrelin-receptor agonists is a prospective therapy for disease-related cachexia and malnutrition. In vitro studies have shown high expression of ghrelin in cancer tissue, although its role including its impact in cancer risk and progression has not been established. We performed a systematic literature review to identify peer-reviewed human or animal in vivo original research studies of ghrelin, ghrelin-receptor agonists, or ghrelin genetic variants and the risk, presence, or growth of cancer using structured searches in PubMed database as well as secondary searches of article reference lists, additional reviews and meta-analyses. Overall, 45 (73.8%) of the 61 studies reviewed, including all 11 involving exogenous ghrelin/ghrelin-receptor agonist treatment, reported either a null (no statistically significant difference) or inverse association of ghrelin/ghrelin-receptor agonists or ghrelin genetic variants with cancer risk, presence or growth; 10 (16.7%) studies reported positive associations; and 6 (10.0%) reported both negative or null and positive associations. Differences in serum ghrelin levels in cancer cases vs controls (typically lower) were reported for some but not all cancers. The majority of in vivo studies showed a null or inverse association of ghrelin with risk and progression of most cancers, suggesting that ghrelin/ghrelin-receptor agonist treatment may have a favorable safety profile to use for cancer cachexia. Additional large-scale prospective clinical trials as well as basic bioscientific research are warranted to further evaluate the safety and benefits of ghrelin treatment in patients with cancer.

Late endocrine effects of childhood cancer

The cure rate for paediatric malignancies is increasing, and most patients who have cancer during childhood survive and enter adulthood. Surveillance for late endocrine effects after childhood cancer is required to ensure early diagnosis and treatment and to optimize physical, cognitive and psychosocial health. The degree of risk of endocrine deficiency is related to the child's sex and their age at the time the tumour is diagnosed, as well as to tumour location and characteristics and the therapies used (surgery, chemotherapy or radiation therapy). Potential endocrine problems can include growth hormone deficiency, hypothyroidism (primary or central), adrenocorticotropin deficiency, hyperprolactinaemia, precocious puberty, hypogonadism (primary or central), altered fertility and/or sexual function, low BMD, the metabolic syndrome and hypothalamic obesity. Optimal endocrine care for survivors of childhood cancer should be delivered in a multidisciplinary setting, providing continuity from acute cancer treatment to long-term follow-up of late endocrine effects throughout the lifespan. Endocrine therapies are important to improve long-term quality of life for survivors of childhood cancer.

Considering GH replacement for GH-deficient adults with a previous history of cancer: a conundrum for the clinician

Previous studies have shown that GH and IGF-I may enhance tumorigenesis, metastasis, and cell proliferation in humans and animals. Evidence supporting this notion is derived from animal model studies, epidemiological studies, experience from patients with acromegaly, molecular therapeutic manipulation of GH and IGF-I actions, and individuals with GH receptor and congenital IGF-I deficiencies. Prior exposure to radiation therapy, aging, family history of cancer, and individual susceptibility may also contribute to increase this risk. Therefore, the use of GH replacement in patients with a history of cancer raises hypothetical safety concerns for patients, caregivers, and providers. Studies of GH therapy in GH-deficient adults with hypopituitarism and childhood cancer survivors have not convincingly demonstrated an increased cancer risk. Conversely, the risk of occurrence of a second neoplasm (SN) in childhood cancer survivors may be increased, with meningiomas being the most common tumor; however, this risk appears to decline over time. In light of these findings, if GH replacement is to be considered in patients with a previous history of cancer, we propose this consideration to be based on each individual circumstance and that such therapy should only be initiated at least 2 years after cancer remission is achieved with the understanding that in some patients (particularly those with childhood cancers), GH may potentially increase the risk of SNs. In addition, close surveillance should be undertaken working closely with the patient's oncologist. More long-term data are thus needed to determine if GH replacement in GH-deficient adults with a history of cancer is associated with the development of de novo tumors and tumor recurrence.

Growth Hormone Protects the Intestine Preserving Radiotherapy Efficacy on Tumors: A Short-Term Study

The efficacy of radiotherapy on tumors is hampered by its devastating adverse effects on healthy tissue, particularly that of the gastrointestinal tract. These effects cause acute symptoms that are so disruptive to patients that they can lead to interruption of the radiotherapy program. These adverse effects could limit the intensity of radiation received by the patient, resulting in a sublethal dose to the tumor, thus increasing the risk of tumor resistance. The lack of an effective treatment to protect the bowel during radiation therapy to allow higher radiation doses that are lethal to the tumor has become a barrier to implementing effective therapy. In this study, we present a comparative analysis of both intestinal and tumor tissue in regard to the efficacy and the preventive impact of a short-term growth hormone (GH) treatment in tumor-bearing rats as a protective agent during radiotherapy. Our data show that the exogenous administration of GH improved intestinal recovery after radiation treatment while preserving the therapeutic effect against the tumor. GH significantly increased proliferation in the irradiated intestine but not in the irradiated tumors, as assessed by Positron Emission Tomography and the proliferative markers Ki67, cyclin D3, and Proliferating Cell Nuclear Antigen. This proliferative effect was consistent with a significant increase in irradiated intestinal villi and crypt length. Furthermore, GH significantly decreased caspase-3 activity in the intestine, whereas GH did not produce this effect in the irradiated tumors. In conclusion, short-term GH treatment protects the bowel, inducing proliferation while reducing apoptosis in healthy intestinal tissue and preserving radiotherapy efficacy on tumors.

Characteristics and outcomes of Italian patients from the observational, multicentre, hypopituitary control and complications study (HypoCCS) according to tertiles of growth hormone peak concentration following stimulation testing at study entry

OBJECTIVE

To determine whether characteristics and outcomes of Italian patients in the observational global Hypopituitary Control and Complication Study (HypoCCS) differed according to the degree of GH deficiency (GHD).

DESIGN

Patients were grouped by tertiles of stimulated GH peak concentration at baseline (Group A lowest tertile, n = 342; Group B middle tertile, n = 345; Group C highest tertile, n = 338).

RESULTS

Baseline demographics, lipid levels, body mass index categories and mean Framingham cardiovascular risk indexes were similar in the three groups and remained substantially unchanged over time, with no subsequent significant between-group differences (except mean levels of triglycerides increased in the highest tertile group). GHD was adult-onset for >75% of patients in all groups. The percentage of patients with multiple pituitary deficiencies was higher in Group A than in the other groups; isolated GHD was reported with highest frequency in Group C. Patients in Group A received the lowest mean starting dose of GH. Hyperlipidaemia at baseline was reported in 35·1%, 31·1% and 24·7% of patients in groups A, B and C, respectively (P = 0·029). Mean duration of GH treatment was 7·21, 5·45 and 4·96 years, respectively. The proportion of patients with adverse events did not differ significantly between groups, with a low prevalence over time of diabetes and cancer.

CONCLUSIONS

In Italian patients from HypoCCS, the level of GH deficit did not influence changes over time in metabolic parameters or adverse event profile, despite differences in GHD severity at baseline and in the starting GH dose.