Growth hormone and tumour recurrence

Hypothalamic-Pituitary and Other Endocrine Surveillance Among Childhood Cancer Survivors

Endocrine disorders in survivors of childhood, adolescent, and young adult (CAYA) cancers are associated with substantial adverse physical and psychosocial effects. To improve appropriate and timely endocrine screening and referral to a specialist, the International Late Effects of Childhood Cancer Guideline Harmonization Group (IGHG) aims to develop evidence and expert consensus-based guidelines for healthcare providers that harmonize recommendations for surveillance of endocrine disorders in CAYA cancer survivors. Existing IGHG surveillance recommendations for premature ovarian insufficiency, gonadotoxicity in males, fertility preservation, and thyroid cancer are summarized. For hypothalamic-pituitary (HP) dysfunction, new surveillance recommendations were formulated by a guideline panel consisting of 42 interdisciplinary international experts. A systematic literature search was performed in MEDLINE (through PubMed) for clinically relevant questions concerning HP dysfunction. Literature was screened for eligibility. Recommendations were formulated by drawing conclusions from quality assessment of all evidence, considering the potential benefits of early detection and appropriate management. Healthcare providers should be aware that CAYA cancer survivors have an increased risk for endocrine disorders, including HP dysfunction. Regular surveillance with clinical history, anthropomorphic measures, physical examination, and laboratory measurements is recommended in at-risk survivors. When endocrine disorders are suspected, healthcare providers should proceed with timely referrals to specialized services. These international evidence-based recommendations for surveillance of endocrine disorders in CAYA cancer survivors inform healthcare providers and highlight the need for long-term endocrine follow-up care in subgroups of survivors and elucidate opportunities for further research.

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 Deficiency and Treatment in Childhood Cancer Survivors

Growth hormone (GH) deficiency is a common pituitary hormone deficiency in childhood cancer survivors (CCS). The identification, diagnosis, and treatment of those individuals at risk are important in order to minimize associated morbidities that can be ameliorated by treatment with recombinant human GH therapy. However, GH and insulin-like growth factor-I have been implicated in tumorigenesis, so there has been concern over the use of GH therapy in patients with a history of malignancy. Reassuringly, GH therapy has not been shown to increase risk of tumor recurrence. These patients have an increased risk for development of meningiomas, but this may be related to their history of cranial irradiation rather than to GH therapy. In this review, we detail the CCS who are at risk for GHD and the existing evidence on the safety profile of GH therapy in this patient population.

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.

Physiologic Growth Hormone-Replacement Therapy and Craniopharyngioma Recurrence in Pediatric Patients: A Meta-Analysis

OBJECTIVE

A systematic review and meta-analysis were conducted to examine the effect of growth hormone-replacement therapy (GHRT) on the recurrence of craniopharyngioma in children.

METHODS

PubMed, Embase, and Cochrane databases were searched through April 2017 for studies that evaluated the effect of GHRT on the recurrence of pediatric craniopharyngioma. Pooled effect estimates were calculated with fixed- and random-effects models.

RESULTS

Ten studies (n = 3487 patients) met all inclusion criteria, including 2 retrospective cohorts and 8 case series. Overall, 3436 pediatric patients were treated with GHRT after surgery and 51 were not. Using the fixed effect model, we found that the overall craniopharyngioma recurrence rate was lower among children who were treated by GHRT (10.9%; 95% confidence interval 9.80%-12.1%; I² = 89.1%; P for heterogeneity <0.01; n = 10 groups) compared with those who were not (35.2%; 95% confidence interval 23.1%-49.6%; I² = 61.7%; P for heterogeneity = 0.11; n = 3); the P value comparing the 2 groups was <0.01. Among patients who were treated with GHRT, subgroup analysis revealed that there was a greater prevalence of craniopharyngioma recurrence among studies conducted outside the United States (P < 0.01), single-center studies (P < 0.01), lower impact factor studies (P = 0.03), or studies with a lower quality rating (P = 0.01). Using the random-effects model, we found that the results were not materially different except for when stratifying by GHRT, impact factor, or study quality; this led to nonsignificant differences. Both Begg's rank correlation test (P = 0.7) and Egger's linear regression test (P = 0.06) indicated no publication bias.

CONCLUSIONS

This meta-analysis demonstrated a lower recurrence rate of craniopharyngioma among children treated with GHRT than those who were not.

Growth hormone therapy and risk of recurrence/progression in intracranial tumors: a meta-analysis

Growth hormone deficiency is common in intracranial tumors, which is usually treated with surgery and radiotherapy. A number of previous studies have investigated the relationship between the growth hormone replacement therapy (GHRT) and risk of tumor recurrence/progression; however, the evidence remains controversial. We conducted a meta-analysis of published studies to estimate the potential relation between GHRT and intracranial tumors recurrence/progression. Three comprehensive databases, PUBMED, EMBASE, and Cochrane Library, were researched with no limitations, covering all published studies till the end of July, 2014. Reference lists from identified studies were also screened for additional database. The summary relative risks (RR) and 95% confidence intervals (CI) were calculated by fixed-effects models for estimation. Fifteen eligible studies, involving more than 2232 cases and 3606 controls, were included in our meta-analysis. The results indicated that intracranial tumors recurrence/progression was not associated with GHRT (RR 0.48, 95% CI 0.39-0.56), and for children, the pooled RR was 0.44 and 95% CI was 0.34-0.54. In subgroup analysis, risks of recurrence/progression were decreased for craniopharyngioma, medulloblastoma, astrocytoma, glioma, but not for pituitary adenomas, and non-functioning pituitary adenoma (NFPA), ependymoma. Results from our analysis indicate that GHRT decreases the risk of recurrence/progression in children with intracranial tumors, craniopharyngioma, medulloblastoma, astrocytoma, or glioma. However, GHRT for pituitary adenomas, NFPA, and ependymoma was not associated with the recurrence/progression of the tumors. GH replacement seems safe from the aspect of risk of tumor progression.

Risk of Neoplasia in Pediatric Patients Receiving Growth Hormone Therapy--A Report From the Pediatric Endocrine Society Drug and Therapeutics Committee

CONTEXT

GH and IGF-1 have been shown to affect tumor growth in vitro and in some animal models. This report summarizes the available evidence on whether GH therapy in childhood is associated with an increased risk of neoplasia during treatment or after treatment is completed.

EVIDENCE ACQUISITION

A PubMed search conducted through February 2014 retrieved original articles written in English addressing GH therapy and neoplasia risk. Subsequent searches were done to include additional relevant publications.

EVIDENCE SYNTHESIS

In children without prior cancer or known risk factors for developing cancer, the clinical evidence does not affirm an association between GH therapy during childhood and neoplasia. GH therapy has not been reported to increase the risk for neoplasia in this population, although most of these data are derived from postmarketing surveillance studies lacking rigorous controls. In patients who are at higher risk for developing cancer, current evidence is insufficient to conclude whether or not GH further increases cancer risk. GH treatment of pediatric cancer survivors does not appear to increase the risk of recurrence but may increase their risk for subsequent primary neoplasms.

CONCLUSIONS

In children without known risk factors for malignancy, GH therapy can be safely administered without concerns about an increased risk for neoplasia. GH use in children with medical diagnoses predisposing them to the development of malignancies should be critically analyzed on an individual basis, and if chosen, appropriate surveillance for malignancies should be undertaken. GH can be used to treat GH-deficient childhood cancer survivors who are in remission with the understanding that GH therapy may increase their risk for second neoplasms.

Association between growth hormone therapy and mortality, cancer and cardiovascular risk: systematic review and meta-analysis

OBJECTIVE

The potential involvement of growth hormone therapy in tumor promotion and progression has been of concern for several decades. Our aim was to assess systematically the association between growth hormone therapy and all-cause, cancer and cardiovascular mortality, cancer morbidity and risk of second neoplasm mainly in patients treated during childhood and adolescence.

DESIGN

A systematic review of all articles published until September 2013 was carried out. The primary efficacy outcome measures were the all-cause, cancer and cardiovascular standardized mortality ratios (SMR). The secondary efficacy outcome measures were the standardized incidence ratio (SIR) for cancer and the relative risk (RR) for second neoplasms. The global effect size was calculated by pooling the data. When the effect size was significant in a fixed model we repeated the analyses using a random model.

RESULTS

The overall all-cause SMR was 1.19 (95% CI 1.08-1.32, p<0.001). Malignancy and cardiovascular SMRs were not significantly increased. Both the overall cancer SIR 2.74 (95% CI 1.18-5.41), and RR for second neoplasms 1.99 (95% CI 1.28-3.08, p=0.002), were significantly increased.

CONCLUSION

The results of this meta-analysis may raise concern on the long-term safety of GH treatment. However, several confounders and biases may affect the analysis. Independent, long-term, well-designed studies are needed to properly address the issue of GH therapy safety.

Final height and insulin-like growth factor-1 in children with medulloblastoma treated with growth hormone

PURPOSE

Medulloblastoma is a highly malignant childhood brain tumor. Survival from medulloblastoma is increasing. This study was performed to examine growth outcomes, insulin-like growth factor-1(IGF-1), and response to growth hormone (GH) treatment in children with medulloblastoma.

METHODS

Retrospective analysis of 34 children treated with GH for medulloblastoma was performed. We evaluated serum IGF-1 and insulin-like growth factor binding protein-3 concentrations. Further, we examined growth status and changes with GH treatment according to treatment modality.

RESULTS

GH deficiency was observed in 28 patients (82 %). The initial height at the start of GH treatment was -2.35 ± -1.53 standard deviation score (SDS) and increased to -1.85 ± -1.28 SDS by 1 year, -1.64 ± -1.46 SDS by 2 years, and -1.42 ± -1.49 SDS by 3 years after GH treatment. The final height was -1.54 ± -1.06 SDS. Gender, surgical method, tumor location, tumor size, and type of radiation did not correlate with height gain. A younger age at the initiation of GH treatment correlated with height gain. The initial serum IGF-1 concentration was -1.73 ± -0.42 and increased significantly to -0.74 ± -0.21 SDS by 1 year after GH treatment. The serum IGF-1 SDS increment correlated significantly with height gain.

CONCLUSIONS

Beginning GH treatment at a younger age was an important prognostic factor for growth outcome. Serum IGF-1 increment correlated with height gain during GH treatment. Thus, early GH treatment and analysis of serum IGF-1 might be helpful for improving final height or growth outcome.

Safety of growth hormone treatment in patients previously treated for cancer

This review provides an overview of the safety of growth hormone replacement therapy in individuals previously treated for cancer. The review focuses on the risk of disease recurrence and second neoplasm occurrence with special attention to data on childhood cancer survivors.

Pediatric brain tumor treatment: growth consequences and their management

Tumors of the central nervous system, the most common solid tumors of childhood, are a major source of cancer-related morbidity and mortality in children. Survival rates have improved significantly following treatment for childhood brain tumors, with this growing cohort of survivors at high risk of adverse medical and late effects. Endocrine morbidities are the most prominent disorder among the spectrum of longterm conditions, with growth hormone deficiency the most common endocrinopathy noted, either from tumor location or after cranial irradiation and treatment effects on the hypothalamic/pituitary unit. Deficiency of other anterior pituitary hormones can contribute to negative effects on growth, body image and composition, sexual function, skeletal health, and quality of life. Pediatric and adult endocrinologists often provide medical care to this increasing population. Therefore, a thorough understanding of the epidemiology and pathophysiology of growth failure as a consequence of childhood brain tumor, both during and after treatment, is necessary and the main focus of this review.

Growth hormone therapy and the risk of tumor recurrence after brain tumor treatment in children

To assess the effect of human growth hormone (hGH) therapy and other factors on tumor recurrence after treatment of pediatric brain tumors (BTs), we retrospectively analyzed data from 108 craniopharyngioma, medulloblastoma, and ependymoma patients. Risk factors were identified using multifactorial univariate regression analysis. Recurrences occurred in 41 and second malignant neoplasms in 4 patients. There were significant correlations for completeness of tumor removal and recurrence-free survival (RFS). 13/44 hGH-treated and 28/59 non-hGH-treated children relapsed. This difference was found only for medulloblastomas and accounted for by higher rates of incomplete tumor removal in non-hGH patients. Craniopharyngioma recurrence correlated only with RFS. Malignant BT recurrence correlated with completeness of tumor removal, chemotherapy, and RFS. 4 children developed SMNs, 3/4 after hGH therapy. Our regression model yielded accurate within-sample prediction of recurrence for 90% of the study population. We conclude that hGH therapy after treatment of pediatric BTs does not increase tumor recurrence risk.

Acromegaly, growth hormone and cancer risk

Acromegaly is an endocrine disorder characterized by sustained hypersecretion of growth hormone (GH) with concomitant elevation of insulin-like growth factor I (IGF-I) associated with premature mortality from cardiopulmonary diseases and certain malignancies. In particular, there is a two-fold increased risk of developing colorectal cancer. Possible mechanisms underlying this association include elevated levels of circulating GH and IGF-I, but several other plausible processes may be relevant. In a parallel literature, there has been debate whether GH replacement therapy is associated with increased cancer risk in three scenarios: (1) tumour recurrence in children with previously treated cancer; (2) second neoplasms (SNs) in survivors of childhood cancer treated with GH; and (3) de-novo cancer in non-cancer patients treated with GH. The general evidence suggests no increased risk in scenario 1. Through a maze of complex study designs, there is inconclusive evidence of a very modest increase in cancer risk in treated GH-deficiency patients in scenarios 2 and 3, but it is likely that the cumulative risk equates to that of the general population. This emphasizes the need for patient selection balanced against the known morbidity of untreated GH deficiency.

Influence of GH substitution therapy in deficient adults on the recurrence rate of hormonally inactive pituitary adenomas: a case control study

OBJECTIVE

Several studies documented metabolic and psychological benefits of GH substitution in deficient adults, most of them suffering from benign pituitary adenomas. Since GH substitution is considered to promote tumour regrowth, adequate treatment is performed with some reservation. Therefore, we aimed to elucidate the effect of GH replacement therapy on tumour recurrence following surgery.

METHODS

In patients with hormonally inactive pituitary adenomas undergoing tumour surgery, a retrospective case-control study was performed. Pre- and postoperative magnetic resonance (MR) images of GH-treated and untreated patients were matched for best fit by two independent observers. The treated patients were retrieved from the surveillance programme of the German KIMS database and the untreated from the database of the Department of Neurosurgery, University of Erlangen. A total of 55 matched pairs were followed for at least 5 years. Tumour recurrence and progression rates were determined according to the postoperative MR.

RESULTS

There were 16 tumour progressions in the treatment group and 12 in the control group. Statistical analysis revealed no significant increase in either recurrence (P = 0.317) or progression (P = 0.617) within the follow-up period of 5 years when GH was adequately replaced.

CONCLUSIONS

This study provides further observational data of substitution therapy in GH-deficient adults with pituitary adenomas. Comparing long-term surgical results, we found no evidence that GH substitution should be withheld in deficient patients. Even residual tumour does not constitute a contraindication to GH replacement. However, since pituitary tumours are slow growing, an observational period of 5 years may not have been long enough to verify any absolute influence on recurrence potential.

Growth hormone treatment and cancer risk

Increasing numbers of children receive growth hormone (GH) to treat a range of growth disorders, including those rendered GH deficient (GHD) by tumors or their treatment. Young persons with persistent growth hormone deficiency (GHD) and adults with severe GHD are also eligible to receive GH treatment. As in vitro and in vivo studies and epidemiologic observations provide some evidence that the GH--insulin like growth factor-I (IGF-I) axis is associated with tumorigenesis, it is important to assess, in practice, the incidence of tumors related to GH treatment. Reassuringly, surveillance studies in large cohorts of children and in smaller cohorts of adults indicate that GH is not associated with an increased incidence of tumor occurrence or recurrence. Nevertheless, all children who have received GH, in particular cancer survivors and those receiving GH in adulthood, should be in surveillance programs to assess whether an increased rate od late-onset and rare tumours may occur.

Recurrence of brain tumours in patients treated with growth hormone: analysis of KIGS (Pfizer International Growth Database)

BACKGROUND

Growth hormone (GH) has been used successfully in the treatment of short stature secondary to GH deficiency in survivors of childhood brain tumours. There has been concern that GH might increase the risk of recurrence.

AIM

To analyse KIGS (Pfizer International Growth Database) with respect to tumour recurrence in patients with brain tumours.

METHODS

Data for tumour recurrence were analysed retrospectively in 1038 patients with craniopharyngiomas, 655 with medulloblastomas, 113 with ependymomas, 297 with germinomas, and 400 with astrocytomas or gliomas. All patients had received recombinant human GH (Genotropin, Pfizer Inc.).

RESULTS

Recurrence-free survival rates were 63% at a follow-up of 10.3 y in craniopharyngioma, 69% in 9.1 y in the glial tumours, 71% in 7.4 y in germinomas, 92% in 4.6 y in medulloblastomas and 89% in 2.5 y in ependymomas. Dose of GH and treatment modalities did not differ significantly between patients with and without recurrence.

CONCLUSION

Tumour recurrence rates in surviving patients with brain tumours receiving GH treatment do not appear to be increased compared with published reports. However, longer follow-up regarding recurrences and secondary neoplasms remains essential.

Pathophysiology of radiation-induced growth hormone deficiency: efficacy and safety of GH replacement

Radiation-induced growth hormone deficiency (GHD) is primarily due to hypothalamic damage. GH secretion by the pituitary may be affected either secondary to some degree of quantitative deprivation of hypothalamic input or, if the radiation dose is high enough, by direct pituitary damage. As a consequence, the neurosecretory profile of GH secretion in an irradiated patient remains pulsatile and qualitatively intact. The frequency of pulse generation is unaffected, but the amplitude of the GH pulses is markedly reduced. Over the last 25 years, the final heights achieved by children receiving GH replacement for radiation-induced GHD have improved; these improvements are attributable to refinements in GH dosing schedules, increased use of GnRH analogues for radiation-induced precocious puberty, and a reduced time interval between completion of irradiation and initiation of GH therapy. When retested at the completion of growth, 80-90% of these teenagers are likely to prove severely GH deficient and, therefore, will potentially benefit from GH replacement in adult life. Such long-term GH treatment in patients treated previously for a brain tumor means that critical and continuous surveillance must be devoted to the risk of tumor recurrence and the possibility of second neoplasms.

Long-term effects of radiation therapy on cognitive and endocrine function in children with leukemia and brain tumors

BACKGROUND

As the number of long-term survivors of childhood cancer has grown, it has become increasingly clear that central nervous system therapy may have serious long-term effects on cognition and endocrine function. These complications have been studied most extensively in children with brain tumors and leukemia.

REVIEW SUMMARY

Children with acute lymphoblastic leukemia previously treated with cranial irradiation are at risk for cognitive decline. Chemotherapy-only regimens, which rely on high-dose frequently administered methotrexate, are also associated with producing cognitive dysfunction. Children irradiated for brain tumors are even more vulnerable. Risk factors include perioperative morbidity, young age, large-volume high-dose cranial irradiation, supra-tentorial location of tumor, moyamoya syndrome, and leukoencephalopathy. Cognitive decline is progressive over at least a decade. The most common radiation-induced endocrinopathies are hypothyroidism and growth hormone deficiency. Treatment effects on growth are multifactorial and include growth hormone deficiency,spinal shortening, precocious puberty, undetected hypothyroidism,and poor nutrition. Fifty percent to 80% of children treated with craniospinal radiation for brain tumors will experience growth failure. In hopes of reducing neurotoxicity, current treatments limit the dose and volume of radiation while adding chemotherapy. Results have not been uniformly positive, however, and may increase toxicity in some cases.

CONCLUSIONS

The standard of care in 2004 is that children who have been treated for brain tumors and leukemia should be monitored for cognitive and endocrine dysfunction. Until effective non-neurotoxic treatment is identified, long-term effects assessments are essential to maximize the quality of life of survivors of childhood cancer.

Growth hormone deficiency and related disorders: insights into causation, diagnosis, and treatment

Advances in molecular biology have led to the identification of mutations within several novel genes associated with the phenotype of isolated growth hormone deficiency, combined pituitary hormone deficiency, and syndromes such as septo-optic dysplasia. Progress has also been made in terms of the optimum diagnosis of disorders of stature and their treatment. The use of growth hormone for the treatment of adults with growth hormone deficiency and conditions such as Turner's syndrome, Prader-Willi syndrome, intrauterine growth restriction, and chronic renal failure has changed the practice of endocrinology, although cost-benefit implications remain to be established.

In vitro effects of recombinant human growth hormone on growth of human gastric cancer cell line BGC823 cells

AIM: To study the effects of recombinant human growth hormone (rhGH) on growth of human gastric cancer cell line in vitro.

METHODS: Experiment was divided into control group, rhGH group, oxaliplatin (L-OHP) group and rhGH+L-OHP group. Cell inhibitory rate, cell cycle, cell proliferation index (PI) and DNA inhibitory rate of human gastric cancer line BGC823, at different concentrations of rhGH treatment were studied by cell culture, MTT assay and flow cytometry.

RESULTS: The distinctly accelerated effects of rhGH on multiplication of BGC823 cell line were not found in vitro. There was no statistical significance between rhGH group and control group, or between rhGH+L-OHP group and L-OHP group (P > 0.05). The cell growth curve did not rise. Cell inhibitory rate and cells arrested in G₀-G₁ phase were obviously increased. Meanwhile, cells in S phase and PI were distinctly decreased and DNA inhibitory rate was obviously increased in rhGH+L-OHP group in comparison with control group and rhGH group, respectively (P < 0.01). Cell inhibitory rate showed an increasing trend and PI showed a decreasing trend in rhGH+L-OHP group compared with L-OHP group.

CONCLUSION: In vitro rhGH does not accelerate the multiplication of human gastric cancer cells. It may increase the therapeutic efficacy when it is used in combination with anticancer drugs.

Cancer Risk Following Growth Hormone Use in Childhood

The therapeutic use of growth hormone (GH) has caused concern, as it is anabolic and mitogenic, and its effector hormone, insulin-like growth factor (IGF)-I is anti-apoptotic. As both hormones can cause proliferation of normal and malignant cells, the possibility that GH therapy may induce cancer, increase the risk of tumour recurrence in those previously treated for a malignancy, or increase the risk of cancer in those with a predisposition, has resulted in concerns over its use. There are theoretical and epidemiological reasons that suggest GH and IGF-I may be important in tumour formation and proliferation. Malignant tumours have been induced in animals exposed to supraphysiological doses of GH, whereas hypophysectomy appears to protect animals from carcinogen-induced neoplasms. In vitro, proliferation and transformation of normal haemopoetic and leukaemic cells occurs with supraphysiological doses of GH, but not with physiological levels. IGF, IGF binding proteins (IGFBP) and IGFBP proteases influence the proliferation of cancer cells in vitro; however, GH is probably not involved in this process. Epidemiological studies have suggested an association between levels of IGF-I and cancer, and an inverse relationship between IGFBP-3 and cancer; however, these associations have been inconsistent. A number of studies have been undertaken to determine the risk of the development of cancer in children treated with GH, either de novo, or the recurrence of cancer in those previously treated for a malignancy. Despite early concerns following a report of a cluster of cases of leukaemia in recipients of GH, there appears to be no increased risk for the development of leukaemia in those treated with GH unless there is an underlying predisposition. Even in children with a primary diagnosis of cancer, subsequent GH use does not appear to increase the risk of tumour recurrence. However, a recent follow-up of pituitary GH recipients has suggested an increase in colorectal cancer. In addition, follow-up of oncology patients has suggested an increase in second neoplasms in those who also received GH therapy. These studies emphasise the importance of continued surveillance both internationally with established databases and also nationally through single-centre studies.

Adverse events with rhGH treatment of patients with chronic renal insufficiency and end-stage renal disease

OBJECTIVE

Recombinant human growth hormone (rhGH) has been used to improve the growth retardation associated with chronic renal insufficiency (CRI) and end-stage renal disease. We determined the incidence of one of four targeted adverse events (AEs): malignancy, slipped capital femoral epiphysis (SCFE), avascular necrosis (AN), and intracranial hypertension (ICH).

STUDY DESIGN

During a 6.5-year period, we prospectively assessed patients enrolled in the CRI, dialysis, and transplant registries of the North American Renal Transplant Cooperative Study. The availability of an untreated control population facilitated determining whether or not there was the association between the AE and rhGH treatment.

RESULTS

Of the targeted AE, the only significant relation with rhGH treatment was the presence of ICH in patients with CRI; however, in all 3 instances, ICH occurred 2, 50, and 1131 days after discontinuation of rhGH. Considering that the mechanism of ICH in rhGH-treated patients is thought to be increased CSF production, rhGH probably had no role in the development of ICH in at least 2 of the 3 patients with CRI. A number of nontargeted AE were identified that have been associated with rhGH treatment in patients without renal disease. The incidence of glucose intolerance, pancreatitis, progressive deterioration of renal function, acute allograft rejection, and fluid retention were not more frequent in those receiving rhGH treatment compared with the control population.

CONCLUSIONS

This report validates the importance of a control population in ascribing AE to any therapeutic intervention. Previously identified AE associated with rhGH treatment are infrequent in patients with CRI and end-stage renal disease.

Long-Term Efficacy and Safety of Somatropin for Adult Growth Hormone Deficiency

The beneficial effects of somatropin (growth hormone [GH] replacement therapy) in adults are now established. Long-term somatropin administration in GH-deficient adults improves body composition, muscle strength, quality of life, bone mass and density, and lipoprotein pattern. The extent to which somatropin therapy can also reduce cardiovascular morbidity and mortality in GH-deficient adults remains to be determined. By starting with a low dose of somatropin, which is gradually increased based on clinical response (body composition, well-being, and serum insulin-like growth factor-1 concentration), effective treatment can be achieved with a minimum of fluid-related adverse effects. Thorough long-term monitoring of glucose metabolism, cardiovascular measurements, and underlying pituitary disease, is, however, mandatory.

Growth hormone replacement therapy in children with leukemia in remission

We describe a patient with leukemia in remission for 7 years who developed growth hormone (GH) deficiency and was treated with recombinant human growth hormone (rhGH). We compare her growth with that of patients from the National Cooperative Growth Study (NCGS) database, 145 with leukemia in remission and 725 with idiopathic growth hormone deficiency (IGHD) on treatment with rhGH. We also review the literature on the risk of relapse of leukemia in similar patients. The patients with leukemia in remission from the NCGS database had a significantly lower change of mean height standard deviation score than that of IGHD patients in the first, second, and third year of rhGH treatment. The relapse rate of leukemia in patients treated with rhGH is between 0.8% and 2%. Starting rhGH therapy in patients with leukemia in remission and with GH deficiency at an adequate dosage and without undue delay would improve their growth response. Such therapy does not appear to increase the risk of leukemia.

Growth hormone therapy in adults

The importance of growth hormone (GH) deficiency in adults became evident 10 to 15 years ago, when the first clinical studies on GH replacement therapy in adults were published. Since then, a number of studies have been reported showing that GH replacement therapy can improve this condition. Adult GH deficiency (GHD) is now recognized as a specific clinical syndrome and the first reports of long-term use of GH (up to 10 years) are now being published. The aim of this paper was to review the accumulated data on the various clinical aspects of adult GHD.

Growth hormone treatment of children with brain tumors and risk of tumor recurrence

GH is increasingly used for treatment of children and adults. It is mitogenic, however, and there is therefore concern about its safety, especially when used to treat cancer patients who have become GH deficient after cranial radiotherapy. We followed 180 children with brain tumors attending three large hospitals in the United Kingdom and treated with GH during 1965-1996, and 891 children with brain tumors at these hospitals who received radiotherapy but not GH. Thirty-five first recurrences occurred in the GH-treated children and 434 in the untreated children. The relative risk of first recurrence in GH-treated compared with untreated patients, adjusted for potentially confounding prognostic variables, was decreased (0. 6; 95% confidence interval, 0.4-0.9) as was the relative risk of mortality (0.5; 95% confidence interval, 0.3-0.8). There was no significant trend in relative risk of recurrence with cumulative time for which GH treatment had been given or with time elapsed since this treatment started. The relative risk of mortality increased significantly with time since first GH treatment. The results, based on much larger numbers than previous studies, suggest that GH does not increase the risk of recurrence of childhood brain tumors, although the rising trend in mortality relative risks with longer follow-up indicates the need for continued surveillance.

Safety issues in children and adolescents during growth hormone therapy--a review

The action of growth hormone (GH) via its receptor involves many organ systems and metabolic pathways. These diverse actions are reviewed in this paper in the context that they may represent unwanted side-effects of GH therapy for growth promotion. The monitoring of GH therapy in large multicentre international databases has demonstrated a low frequency of adverse events. Tumour recurrence or new malignancy are not increased. Headaches, especially in the first few months of therapy, require close evaluation as benign intracranial hypertension is found infrequently, especially in children with GH deficiency and chronic renal failure (CRF). Children at risk for slipped capital femoral epiphysis and scoliosis require close monitoring during therapy. Decreased insulin sensitivity that is dose-dependent is observed during GH therapy. Glucose homeostasis, however, is not affected, but a recent report of increased incidence of Type 2 diabetes mellitus in children undergoing GH therapy requires prospective surveillance.

No evidence of tumor growth stimulation in human tumors in vitro following treatment with recombinant human growth hormone

In a recent study we demonstrated that recombinant human growth hormone (r-hGH; Saizen) delayed tumor-induced cachexia in human tumor xenografts in vivo. Such a therapeutic effect could have a great impact in the supportive care of advanced cancer patients. Before large clinical studies are initiated possible growth stimulation should be excluded. This question was investigated in vitro in 20 human tumor models, which had been established in serial passage in nude mice. The effect of continuous exposure of r-hGH was investigated at dose levels ranging from 0.3 ng/ml up to 0.1 microg/ml in colorectal (n=2), gastric (n=1), non-small cell lung (n=4), small cell lung (n=1), mammary (n=3), ovarian (n=2), prostate (n=2) and renal cancers (n=2), and melanoma (n=3) using a modified Hamburger and Salmon clonogenic assay. The results show that there was neither tumor growth inhibition nor any evidence for tumor growth stimulation in any of the tumors studies. Therefore this preclinical study in 20 human tumor models indicated no direct risk for tumor growth enhancement.

Long-term risk of gastrointestinal tumor recurrence after postoperative treatment with recombinant human growth hormone

BACKGROUND

Recombinant human growth hormone (rhGH) promotes protein synthesis, accelerates wound healing, and maintains immune function in the catabolic state. It has also been claimed that rhGH may promote the activation of residual tumor cells, and therefore, increases the risk of tumor recurrence. This study aimed to investigate whether postoperative administration of rhGH increases the long-term risk of tumor recurrences in patients undergoing major gastrointestinal surgery for malignancy.

METHODS

Patients (n =104) received three different doses of rhGH (0.075 IU/kg, 0.150 IU/kg, and 0.300 IU/kg) during 5 postoperative days in a placebo-controlled trial. Follow-up was performed for 56-70 months after radical tumor resection. Mean survival period and relapse-free survival were compared with the control group.

RESULTS

Complete data were available for 75 patients. Thirty-five percent (n = 20) of all patients treated with rhGH showed tumor recurrences in comparison to 44% (n = 8) of patients given placebo. Mean survival period for rhGH-treated patients was 46 months (median 59 months); in controls, 42 months (median 58 months). The length of relapse-free survival tended to be longer in rhGH-treated patients (2-47 months; median, 21 months) compared with the patients who were given placebo (2-18 months; median, 13 months).

CONCLUSIONS

The results demonstrate no evidence for an increased risk of tumor recurrence after rhGH treatment for a short period of time after removal of a gastrointestinal adenocarcinoma. Therefore, the positive metabolic effects of rhGH application can be used safely in the treatment of the postoperative catabolic state in the patient groups investigated.

One year growth hormone replacement therapy does not alter colonic epithelial cell proliferation in growth hormone deficient adults

OBJECTIVE

Increased colonic epithelial cell proliferation has been found in various conditions associated with increased risk of colorectal cancer including acromegaly. In a placebo-controlled study we determined the effect of growth hormone (GH) replacement therapy in GH deficient adults on the colonic epithelial proliferation rate.

PATIENTS AND DESIGN

Sixteen GH deficient adults were randomised to low dose GH therapy (1 U (0.5 mg) subcutaneously per day, n = 5), high dose GH therapy (2 U daily, n = 5) or placebo (n = 6) during 6 months. Thereafter, all patients were treated with 2 U of GH daily during a 6-months open extension period.

MEASUREMENTS

Plasma Insulin-like growth hormone I (IGF-I) and IGF binding protein 3 (IGF BP3) concentrations were measured using commercial RIA kits. The colonic epithelial proliferation rate, expressed as overall crypt labelling index (LI) using 5-bromo-2'-deoxyuridine (BrdU) immunostaining, was determined at baseline, after 6 months treatment and at the end of the 6 months open extension period.

RESULTS

IGF-I rose from 8.9 +/- 6.7 to 34.6 +/- 20.0 nmol/l after 6 months in 8 GH treated patients (P < 0.01 from baseline; P < 0.01 from change with placebo). In the extension study, plasma IGF-I was also increased in the patients who previously received placebo (P < 0.02, n = 5). LI was evaluable in 14 biopsies at baseline, in 16 after 6 months and in 14 after 12 months. Overall crypt LI did not change in 8 GH treated patients after 6 months (P > 0.40 from baseline; P > 0.80 from change with placebo). In the extension study, overall crypt LI was also unchanged in those patients who received GH after placebo (n = 5, P > 0.40) and in those who continued GH replacement (n = 9, P > 0.60; P > 0.80 from change in initially placebo treated patients). Separate evaluation of the LI at the basal, mid and luminal portions of the colonic crypts also did not reveal any effect of GH treatment on BrdU labelling.

CONCLUSIONS

Six to 12 months of GH replacement therapy, aimed to increase plasma IGF-I into the (high) physiological range, does not adversely affect colonic epithelial cell proliferation as a biomarker for the risk of development of colorectal cancer.

Adult growth hormone deficiency syndrome: a personal approach to diagnosis, treatment and monitoring

Therapy guidelines and monitoring should focus on symptoms and, from a laboratory standpoint, serum IGF-I concentrations. Successful interaction between the patient and the physician depends on awareness of the symptoms of the adult GHD syndrome and those associated with replacement therapy. Successful GH replacement therapy can lead to significant improvement in the patient's condition with great satisfaction with the treatment being expressed by the patient, their family and the physician.

Increased incidence of neoplasia in patients with pituitary adenomas. The Pituitary Study Group

OBJECTIVE

The goal of our study was to determine the rate of neoplasms in patients with other pituitary adenomas (non-functioning and prolactinomas) in comparison with acromegaly which is known to favour the development of neoplasia.

DESIGN AND PATIENTS

We reviewed clinical records for 220 patients with acromegaly, 151 patients with non-functioning pituitary adenoma (NF) and 98 patients with prolactinomas. Incidence rates of cancer for patients with pituitary tumours were calculated per person-years of follow-up study. These rates were then compared with sex and age adjusted incidence rates reported by National Tumour Registry. An internal control group of 163 subjects with a non-neoplastic condition, i.e. Graves' disease followed chronically in the same clinic was also studied. The ratios observed to expected were expressed as standardized incidence rates (SIR). The only significant difference between the acromegalic and other pituitary tumours patients was in hypopituitarism, present in 18.2% (acromegaly) 47% (NF) and 18.6% (prolactinomas).

RESULTS

Twenty-three malignant tumours were registered in 19 acromegalics (1 Hodgkin disease, 1 myelogenous leukaemia, 1 lymphocytic leukaemia, 3 papillary thyroid carcinomas, 1 ovarian carcinoma, 2 colorectal carcinoma, 1 renal cell carcinoma, 4 cervical carcinoma, 2 skin cancers, 2 pancreatic carcinoma, 4 breast carcinoma, 1 bladder carcinoma). Three acromegalics harboured two malignancies. Patients with acromegaly had a 3.39-fold increased rate of malignant tumours compared with the general population and a 3.21-fold increased rate compared with our internal control group. Eleven malignant tumours were found in patients with NF-pituitary adenomas and 2 in prolactinoma patients (1 lymphoma, 1 multiple myeloma, 1 colonic cancer, 1 renal cell cancer, 1 stomach cancer, 2 lung cancers, 1 cervix carcinoma, 1 breast cancer, 1 testicular carcinoma and 3 melanoma). Patients with NF pituitary adenomas had a 3.91-fold increased rate of malignant tumours compared with the general population and 4.07-fold increase compared with the internal control group. Patients harbouring prolactinomas did not have an increased incidence rate of malignancy compared with the general population or our internal controls. Female patients with acromegaly and male patients with NF-pituitary adenoma had higher incidences of neoplasia.

CONCLUSION

We have demonstrated that the overall incidence of malignant tumours in patients with non-functioning pituitary adenomas and acromegaly is significantly higher than expected for general population and for our internal control group.

[Late effects of radiotherapy on the neuroendocrine system]

When the hypothalamic-pituitary axis (HPA) is included in the treatment field in children and adults, a variety of neuroendocrine disturbances are more common than has been appreciated in the past. Clinical damage to the pituitary and thyroid glands usually occurs months to years after treatment, and is preceded by a long subclinical phase. Primary brain tumors represent the largest group of malignant solid tumors in children. The survival rates of 50% reported in the literature are achieved at the expense of late occurring effects. Radiation-induced abnormalities are generally dose-dependent. Growth hormone deficiency and premature sexual development can occur at doses as low as 18 Gy in conventional fractionation, and is the most common neuroendocrine problem in children. In patients treated with > 40 Gy on the HPA, deficiency of gonadotropins, thyroid stimulating hormone, and adrenocorticotropin can be found. Following high-dose radiotherapy (> 50 Gy), hyperprolactinemia can be seen, especially among young women. Most neuroendocrine disturbances that develop as a result of HPA can be treated efficiently, provided that an early detection of these endocrine dysfunctions abnormalities is done.

Relapse of intracranial germinoma 23 years postirradiation in a patient given growth hormone replacement

There is no clear evidence that growth hormone replacement therapy for treatment-related growth hormone deficiency in patients with childhood intracranial malignancies has a role in tumour relapse or second malignancy. A 16-year-old girl with an intracranial germinoma was treated with local radiotherapy and subsequently received growth hormone replacement therapy as an adult. Three years after starting growth hormone therapy, 23 years after her radiotherapy treatment, the patient's tumour recurred. Surveillance requirements for patients receiving growth hormone in this setting are discussed.

Growth and neuroendocrine dysfunction following therapy for childhood cancer

Poor linear growth and short adult stature are common complications following successful treatment of childhood cancer. Although several factors contribute to the impaired growth of these patients, growth potential is most reduced following radiotherapy to the head or spine. Younger age at treatment and female sex seem to be significant and independent risk factors for short adult height. Early diagnosis and timely therapy of the endocrine sequelae of cancer treatment (i.e., GH deficiency, hypothyroidism, and precocious puberty) ensure that these individuals will reach their optimum growth potential. For patients exposed to high-dose radiotherapy (> 35-40 Gy) to the region of the hypothalamus and pituitary gland, a variety of neuroendocrine abnormalities in addition to GH deficiency and early sexual development may occur, including deficiencies of LH/FSH, TSH, and ACTH as well as hypersecretion of prolactin. Because these problems may develop many years after irradiation, patients at risk for neuroendocrine disturbances require long-term endocrine follow-up.

Adult height after cranial irradiation with 24 Gy: factors and markers of height loss

The decrease in adult height of children who have been given cranial irradiation (24 Gy) for acute lymphoblastic leukaemia is attributed to chemotherapy, growth hormone (GH) deficiency and early puberty. This study evaluates the factors involved in the height loss between irradiation and adult height and its markers in 43 patients irradiated at 5.8 +/- 0.4 (SEM) years. The mean height loss was 0.9 +/- 0.2 SD in the children with a normal GH peak (n = 11), 1.7 +/- 0.2 SD in those with a low GH peak and untreated (n = 15) and 0.6 +/- 0.2 SD in those treated with GH (n = 17). The adult height was significantly lower than target height in all three groups. The height loss correlated negatively with the GH peak (p < 0.02) and with the age at onset of puberty (p < 0.05) in the first two groups with spontaneous growth, but not with the chemotherapy regimen or its duration, or the plasma insulin-like growth factor I (IGFI) and its GH-dependent binding protein (BP-3). Early puberty (onset at 8-10 years) occurred in 6 girls from the first two groups. At the first evaluation, 5.6 +/- 0.4 years after irradiation, the GH peak values after arginine-insulin stimulation correlated with the age at irradiation (p < 0.03), taking into account the time since irradiation. The plasma IGFI and BP-3 values were correlated with each other, but not with the GH peak. In conclusion, this study demonstrates the impact of GH deficiency and GH replacement therapy on adult height in children given cranial irradiation for leukaemia. They therefore should be evaluated for their GH secretion 1-2 years after the end of chemotherapy. GH therapy is indicated for those with low GH peak and decreased growth rate or no increase in growth rate despite puberty.

Brain tumor recurrence in children treated with growth hormone: the National Cooperative Growth Study experience

As of October 1993 the National Cooperative Growth Study included 1262 children with brain tumor who were treated with growth hormone. The type of brain tumor was specified in 947 (75%) of these children. The most common types were glioma, medulloblastoma, and craniopharyngioma, accounting for 91.3% of all those for which type was specified. Brain tumor recurred in 83 (6.6%) of the 1262 children over a total of 6115 patient-years at risk. The frequencies of tumor recurrence in children with low-grade glioma (18.1%), medulloblastoma (7.2%), and craniopharyngioma (6.4%) are lower than those in published reports of tumor recurrence in the general pediatric population with the same types of tumors. The analysis cannot conclusively show that no increased risk of tumor recurrence exists, however, because of the potential incompleteness of data reporting in the National Cooperative Growth Study. Nevertheless the findings are reassuring that children with the more common types of brain tumor who are treated with growth hormone do not seem to be at excessive risk for tumor recurrence.

Secondary Amenorrhoea after Total Body Irradiation in Pre-Puberty

Bone marrow transplant (BMT) has been used as part of the overall treatment of refractory malignant diseases. High dose cyclophosphamide and total body irradiation (TBI) are frequently used as conditioning for BMT. Initial regimens included a single fraction of TBI, with doses varying from 7.5-1O Gy, but this was associated with a high incidence of late sequelae including multiple endocrinopathies1. A fractionated irradiation course over 3-4 days of a higher total dose, 12-15 Gy, of TBI is now used1,2. Successfully treated patients with childhood cancer have an increased risk, of developing second tumours. We describe a patient successfully treated for AML who developed multiple endocrine dysfunction and a second benign ovarian tumour.