Comparative effectiveness review of treatment options for pituitary microadenomas in acromegaly

The socioeconomic burden of acromegaly

Acromegaly is a rare and insidious disease characterized by chronic excess growth hormone, leading to various morphological changes and systemic complications. Despite its low prevalence, acromegaly poses a significant socioeconomic burden on patients and healthcare systems. This review synthesizes the current state of knowledge on the psychosocial burden, disability, impact on daily life, and cost of acromegaly disease, focusing on the quality of life, partnership, medical care and treatment afflictions, participation in daily activities, professional and leisure impairment, and cost of treatment for acromegaly and its comorbidities. It also examines management strategies, coping mechanisms, and interventions aimed at alleviating this burden. A comprehensive understanding of the extent of the socioeconomic burden in acromegaly is crucial to develop effective strategies to improve treatment and care. Further research is warranted to explore the myriad factors contributing to this burden, as well as the efficacy of interventions to alleviate it, ultimately enhancing the quality of life for patients with acromegaly.

Mapping of the acromegaly quality of life questionnaire to ED-5D-5L index score among patients with acromegaly

OBJECTIVE

This study aimed to develop a mapping function that links the acromegaly quality of life (AcroQoL) questionnaire to EQ-5D-5L to obtain a preference-based utility value to inform economic evaluation.

METHODS

A nationwide cross-sectional questionnaire survey among patients with acromegaly was conducted online in China during 17 December 2019 to 6 January 2020. The study sample was randomly divided into a training set and a validation set. Ordinary least squares (OLS), Tobit, beta-based mixture, and adjusted limited dependent variable mixture models were tested for development of the function in the training set. Total and subscale scores and individual items of AcroQoL were included as predictors in the models along with their squared terms and demographic and clinical characteristics, and selected by backward stepwise selection. The root mean square error, mean absolute error, Akaike's information criterion, Bayesian information criterion and adjusted R-square were used to assess goodness of fit and predictive ability of the models.

RESULTS

There were 424 adult patients with acromegaly eligible for this analysis. Average EQ-5D-5L index score and AcroQoL score for them was 0.82 (SD = 0.15) and 44.3 (SD = 22.9), respectively. A total of 60 candidate models were tested. Considering model simplicity and predictive ability in both training and validation set, the best model was the OLS model using scores of physical dimension and its square term as predictors.

CONCLUSION

A validated mapping function was developed in this study for estimating EQ-5D scores using AcroQoL outcomes. Its external validity can be further tested in other population with Acromegaly.

Cost-Utility of Acromegaly Pharmacological Treatments in a French Context

Objective

Efficacy of pharmacological treatments for acromegaly has been assessed in many clinical or real-world studies but no study was interested in economics evaluation of these treatments in France. Therefore, the objective of this study was to estimate the cost-utility of second-line pharmacological treatments in acromegaly patients.

Methods

A Markov model was developed to follow a cohort of 1,000 patients for a lifetime horizon. First-generation somatostatin analogues (FGSA), pegvisomant, pasireotide and pegvisomant combined with FGSA (off label) were compared. Efficacy was defined as the normalization of insulin-like growth factor-1 (IGF-1) concentration and was obtained from pivotal trials and adjusted by a network meta-analysis. Costs data were obtained from French databases and literature. Utilities from the literature were used to estimate quality-adjusted life year (QALY).

Results

The incremental cost-utility ratios (ICUR) of treatments compared to FGSA were estimated to be 562,463 € per QALY gained for pasireotide, 171,332 € per QALY gained for pegvisomant, and 186,242 € per QALY gained for pegvisomant + FGSA. Pasireotide seems to be the least cost-efficient treatment. Sensitivity analyses showed the robustness of the results.

Conclusion

FGSA, pegvisomant and pegvisomant + FGSA were on the cost-effective frontier, therefore, depending on the willingness-to-pay for an additional QALY, they are the most cost-effective treatments. This medico-economic analysis highlighted the consistency of the efficiency results with the efficacy results assessed in the pivotal trials. However, most recent treatment guidelines recommend an individualized treatment strategy based on the patient and disease profile.

GH and IGF-I levels and tumor shrinkage in response to first generation somatostatin receptor ligands in acromegaly: a comparative study between two reference centers for pituitary diseases in Brazil

PURPOSE

To compare biochemical and tumor response rates between two reference centers for pituitary diseases in Brazil after primary and adjuvant therapy with somatostatin receptor ligands (SRL) in acromegaly.

METHODS

Patients were classified as non-responders (NR), partial responders (PR), and full responders (FR) to 12-month SRL therapy according to: [criteria A] normal IGF-I and random GH (rGH) < 1 ng/mL (FR); ≥ 50% decrease of IGF-I and/or rGH (PR); < 50% decrease of IGF-I and rGH (NR); [criteria B] normal IGF-I (FR); ≥ 50% decrease of IGF-I (PR); < 50% decrease of IGF-I (NR). Tumor shrinkage <20% defined poor responders (tPR) and ≥ 20% good responders (tGR).

RESULTS

We studied 219 acromegaly patients (59% women, age 43.1 ± 13.9 years; 73 from Center I and 146 from Center II). After SRL therapy, the proportion of FR, PR, and NR by criteria A and B was 30.2 vs 49.1%, 52.8 vs 21.2% and 17 vs 29.7%, respectively (p < 0.001). Considering criteria A or B separately, there was no difference in the proportion of FR, PR and NR between two centers. However, when comparing criteria A and B, the Center I showed a difference of 30.9% in classification of FR in relation to 13.2% observed in Center II (p = 0.006). tGR were 51.4% of patients, with no differences between the centers.

CONCLUSIONS

IGF-I alone significantly increased positive response rates to SRLs, whereas the inclusion of rGH levels into therapeutic decision might lead to a significant increment on the costs of acromegaly management.

Endoscopic endonasal lateral transellar approach for growth hormone-secreting adenomas with cavernous sinus invasion: Technical note and surgical results

BACKGROUND

Cavernous sinus (CS) invasion is found in 15-20% of pituitary adenomas; it represents a poor prognosis factor and a surgical challenge even in experienced pituitary centers. We present our experience and technical note description for surgical management of pituitary adenomas with CS invasion in acromegaly by the transsellar lateral approach with an endoscopic endonasal transsphenoidal route.

METHOD

prospective case series of patients who underwent endoscopic endonasal surgery for Growing Hormone (GH) producing adenomas with CS invasion treated at the Neurosurgery departments of National Institute of Neurology and Neurosurgery in Mexico City, and of Toluca Medical Center of Social Security Institute of the State of Mexico and Provinces between January 2014 and March 2019.

RESULTS

Thirty-two of 94 patients with diagnosis of pituitary adenoma treated at our institutions (34%) had acromegaly; thirteen of patients with acromegaly diagnosis met the inclusion criteria for CS invasion. Postoperative images reported gross total resection in 10 patients (76.9%). Mean follow-up time was 28.3 months. Remission criteria were achieved in nine patients (69.2%), with one of these patients (11.1%) having recurrence during follow up. All patients with no biochemical remission had improvement in GH and IGF profiles. Three patients without remission underwent radiosurgery (14Gy), and one patient had remission after the procedure.

CONCLUSIONS

We consider this to be a safe and efficient approach for tumors invading CS, when surgical team have good experience in endoscopy of the skull base and reconstruction techniques, appropriate instruments are available, and tumor has soft consistency.

PET-guided repeat transsphenoidal surgery for previously deemed unresectable lateral disease in acromegaly

OBJECTIVE

The object of this study was to determine if revision transsphenoidal surgery (TSS), guided by 11C-methionine PET/CT coregistered with volumetric MRI (Met-PET/MRCR), can lead to remission in patients with persistent acromegaly due to a postoperative lateral disease remnant.

METHODS

The authors identified 9 patients with persistent acromegaly following primary intervention (TSS ± medical therapy ± radiotherapy) in whom further surgery had initially been discounted because of equivocal MRI findings with suspected lateral sellar and/or parasellar disease (cases with clear Knosp grade 4 disease were excluded). All patients underwent Met-PET/MRCR. Scan findings were used by the pituitary multidisciplinary team to inform decision-making regarding repeat surgery. Revision TSS was performed with wide lateral exploration as guided by the PET findings. Endocrine reassessment was performed at 6-10 weeks after surgery, with longitudinal follow-up thereafter.

RESULTS

Met-PET/MRCR revealed focal tracer uptake in the lateral sellar and/or parasellar region(s) in all 9 patients, which correlated with sites of suspected residual tumor on volumetric MRI. At surgery, tumor was identified and resected in 5 patients, although histological analysis confirmed somatotroph tumor in only 4 cases. In the other 4 patients, no definite tumor was seen, but equivocal tissue was removed. Despite the uncertainty at surgery, all patients showed immediate significant improvements in clinical and biochemical parameters. In the 8 patients for whom long-term follow-up data were available, insulin-like growth factor 1 (IGF-1) was ≤ 1.2 times the upper limit of normal (ULN) in all subjects and ≤ 1 times the ULN in 6 subjects, and these findings have been maintained for up to 28 months (median 8 months, mean 13 months) with no requirement for adjunctive medical therapy or radiotherapy. No patient suffered any additional pituitary deficit or other complication of surgery.

CONCLUSIONS

This study provides proof of concept that Met-PET/MRCR can be helpful in the evaluation of residual lateral sellar/parasellar disease in persistent acromegaly and facilitate targeted revision TSS in a subgroup of patients.

Cost-Effectiveness and Efficacy of a Novel Combination Regimen in Acromegaly: A Prospective, Randomized Trial

CONTEXT

Combination therapy with somatostatin receptor ligand (SRL) plus pegvisomant for patients with acromegaly is recommended after a maximizing dose on monotherapy. Lower-dose combination regimens are not well studied.

OBJECTIVE

To compare cost-effectiveness and efficacy of 3 lower-dose combination regimens in controlled and uncontrolled acromegaly.

DESIGN AND SETTING

Prospective, randomized, open-label, parallel arm study at a tertiary referral pituitary center.

PATIENTS

Adults with acromegaly regardless of response to prior SRL and biochemical control status at baseline, stratified by an SRL dose required for insulin-like growth factor (IGF)-I normalization during any 3-month period within 12 months preceding enrollment.

INTERVENTION

Combination therapy for 24 to 32 weeks on arm A, high-dose SRL (lanreotide 120 mg/octreotide long-acting release [LAR] 30 mg) plus weekly pegvisomant (40-160 mg/week); arm B, low-dose SRL (lanreotide 60 mg/octreotide LAR 10 mg) plus weekly pegvisomant; or arm C, low-dose SRL plus daily pegvisomant (15-60 mg/day).

MAIN OUTCOME MEASURE

Monthly treatment cost in each arm in participants completing ≥ 24 weeks of therapy.

RESULTS

Sixty patients were enrolled and 52 were evaluable. Fifty of 52 (96%) demonstrated IGF-I control regardless of prior SRL responsiveness (arm A, 14/15 [93.3%]; arm B, 22/23 [95.7%]; arm C, 14/14 [100%]). Arm B was least costly (mean, $9837 ± 1375 per month), arm C was most expensive (mean, $22543 ± 11158 per month), and arm A had an intermediate cost (mean, $14261 ± 1645 per month). Approximately 30% of patients required pegvisomant dose uptitration. Rates of adverse events were all < 10%.

CONCLUSIONS

Low-dose SRL plus weekly pegvisomant represents a novel dosing option for achieving cost-effective, optimal biochemical control in patients with uncontrolled acromegaly requiring combination therapy.

Endoscopic endonasal lateral transellar approach for growth hormone-secreting adenomas with cavernous sinus invasion: Technical note and surgical results

BACKGROUND

Cavernous sinus (CS) invasion is found in 15-20% of pituitary adenomas; it represents a poor prognosis factor and a surgical challenge even in experienced pituitary centers. We present our experience and technical note description for surgical management of pituitary adenomas with CS invasion in acromegaly by the transsellar lateral approach with an endoscopic endonasal transsphenoidal route.

METHOD

prospective case series of patients who underwent endoscopic endonasal surgery for Growing Hormone (GH) producing adenomas with CS invasion treated at the Neurosurgery departments of National Institute of Neurology and Neurosurgery in Mexico City, and of Toluca Medical Center of Social Security Institute of the State of Mexico and Provinces between January 2014 and March 2019.

RESULTS

Thirty-two of 94 patients with diagnosis of pituitary adenoma treated at our institutions (34%) had acromegaly; thirteen of patients with acromegaly diagnosis met the inclusion criteria for CS invasion. Postoperative images reported gross total resection in 10 patients (76.9%). Mean follow-up time was 28.3 months. Remission criteria were achieved in nine patients (69.2%), with one of these patients (11.1%) having recurrence during follow up. All patients with no biochemical remission had improvement in GH and IGF profiles. Three patients without remission underwent radiosurgery (14Gy), and one patient had remission after the procedure.

CONCLUSIONS

We consider this to be a safe and efficient approach for tumors invading CS, when surgical team have good experience in endoscopy of the skull base and reconstruction techniques, appropriate instruments are available, and tumor has soft consistency.

NECESSITY OF MULTIMODAL TREATMENT OF ACROMEGALY AND OUTCOMES

OBJECTIVE

Uncontrolled acromegaly is associated with increased morbidity and mortality. Despite multimodal therapeutic options, adequate control can be challenging and lead to prolonged exposure to growth hormone excess. The aim of this study was to assess treatment patterns and outcomes in patients with acromegaly following surgery at a single institution.

METHODS

A retrospective analysis of response to treatment modalities for patients with a new diagnosis of acromegaly at the Mayo Clinic in Rochester, Minnesota, from 1995-2015.

RESULTS

A total of 245 patients with newly diagnosed acromegaly (mean age at diagnosis, 47 ± 14 years; mean follow-up, 5.5 ± 5 years) were evaluated. Primary surgical intervention was performed in 236 patients; 117 (54%) did not achieve remission. Among those with ≥3 months follow-up, 76/217 (35%) patients required three or more forms of treatment. Mean tumor size at diagnosis was 1.6 ± 0.8 cm (80% macroadenomas), and 35% (75/217) had cavernous sinus invasion on pre-operative imaging. The most common second-line treatment was radiation treatment (RT) (50%, 59/117). Among those with persistent disease following surgery, a normal insulin-like growth factor 1 (IGF-1) was achieved in 52% (61/117), with a median time to acromegaly control of 4.5 years. The rate of IGF-1 normalization was 2.1-fold higher in those who received RT compared to those who did not.

CONCLUSION

In patients with persistent acromegaly following surgery, multiple treatment modalities, including RT, may be required to achieve remission. Treatment outcome uncertainty and the need for multiple interventions add to the disease burden associated with persistent acromegaly.

ABBREVIATIONS

CI = confidence interval; GH = growth hormone; IGF-1 = insulin like growth factor-1; KM = Kaplan-Meier; RT = radiation treatment.

Cost-effectiveness of acromegaly treatments: a systematic review

PURPOSE

Acromegaly is a rare disease that results in the enlargement of body extremities and in organomegaly. Treatments include surgery, drugs, and radiotherapy, which are all onerous. Therefore, well-conducted cost-analyses are crucial in the decision-making process.

METHODS

A systematic review of cost-effectiveness studies on acromegaly therapies was performed following PRISMA and Cochrane recommendations. The search for records was conducted in PubMed, Scopus, and Web of Science (May 2018). The quality of the included studies was assessed using the Joana Briggs Institute Tool.

RESULTS

From initial 547 records, 16 studies were included in the review. The studies could present more than one economic evaluation, and encompassed cost-effectiveness (n = 13), cost-utility (n = 5), and cost-consequence (n = 1) analyses. All studies were model-based and evaluated only direct medical costs. Eleven records did not mention discounting and only 10 performed sensitivity analyses. The characteristic of the studies, the cost-effectiveness results and the studies' conclusions are described and commented upon. The main limitation of the studies was discussed and aspects to improve in future studies were pointed out.

CONCLUSIONS

Cost-effectiveness studies on acromegaly have been performed in several scenarios, evaluating different phases of treatment. However, the studies present limitations and, overall, were considered of moderate quality. Further economic models should be developed following health economics guidelines recommendations, and must improve transparency.

Cost-effectiveness of somatostatin analogues in the treatment of acromegaly

INTRODUCTION

Somatostatin analogues (SSAs) are the largest contributor to the direct medical cost of acromegaly management worldwide. The aim of this review was to identify and report available evidence on the cost-effectiveness of SSAs in the treatment of acromegaly.

AREAS COVERED

A literature search on relevant papers published up to April 2018 was performed. A total of 22 eligible studies (10 full-text articles and 12 conference abstracts) conducted in 14 countries were included in the analysis. In majority of studies, modelling technique was the principal research method.

EXPERT COMMENTARY

The results of cost-effectiveness analyses: 1) support published recommendations where SSAs are indicated as first-line medical treatment for patients with persistent disease after surgery or who are not eligible for surgery; 2) suggest that preoperative medical therapy with SSAs may be highly cost-effective in acromegalic patients with macroadenoma, in centres without optimal surgical results 3) indicate that in some countries pasireotide and pegvisomant appeared to be cost-effective or even dominant strategies in comparison to first-generation SSAs. The main limitation of economic evaluations was the lack of high-quality studies designed to directly compare various treatment strategies in acromegaly.

Long-Term Endocrine Outcomes Following Endoscopic Endonasal Transsphenoidal Surgery for Acromegaly and Associated Prognostic Factors

BACKGROUND

Long-term remission rates from endoscopic transsphenoidal surgery for acromegaly and their relationship to prognostic indicators of disease aggressiveness are not well documented.

OBJECTIVE

To investigate long-term remission rates in patients with acromegaly after endoscopic transsphenoidal surgery, and correlate this with molecular and radiographic markers of disease aggressiveness.

METHODS

We identified all patients undergoing endoscopic transsphenoidal surgery for acromegaly from 2005 to 2013 at Cedars-Sinai Pituitary Center. Hormonal remission was established by normal insulin-like growth factor (IGF)-1, basal serum growth hormone <2.5 ng/mL, and growth hormone suppression to <1 ng/mL following oral glucose tolerance test. Oral glucose tolerance test was performed at 3 months after surgery, and then as indicated. IGF-1 was measured at 3 months and then at least annually. We evaluated tumor granularity, nuclear expression of p21, Ki67 index, and extent of cavernous sinus invasion, and correlated these with remission status.

RESULTS

Fifty-eight patients that underwent surgery had follow-up from 38 to 98 months (mean 64 ± 32.2 months). There were 21 microadenomas and 37 macroadenomas. Three months after surgery 40 of 58 patients (69%) were in biochemical remission. Four additional patients were in remission at 6 months after surgery, and 1 patient had recurrence within the first year after surgery. At last follow-up, 43 of 44 (74.1%) of patients remained in remission. Cavernous sinus invasion by tumor predicted failure to achieve remission.

CONCLUSIONS

Prognostic markers of disease aggressiveness other than cavernous sinus invasion did not correlate with surgical outcome. Long-term remission after surgery alone was achieved in 74% of patients, indicating long-term efficacy of endoscopic surgery.

Cost-Effectiveness Analysis of Surgical versus Medical Treatment of Prolactinomas

Background Few studies address the cost of treating prolactinomas. We performed a cost-utility analysis of surgical versus medical treatment for prolactinomas. Materials and Methods We determined total hospital costs for surgically and medically treated prolactinoma patients. Decision-tree analysis was performed to determine which treatment produced the highest quality-adjusted life years (QALYs). Outcome data were derived from published studies. Results Average total costs for surgical patients were $19,224 ( ± 18,920). Average cost for the first year of bromocriptine or cabergoline treatment was $3,935 and $6,042, with $2,622 and $4,729 for each additional treatment year. For a patient diagnosed with prolactinoma at 40 years of age, surgery has the lowest lifetime cost ($40,473), followed by bromocriptine ($41,601) and cabergoline ($70,696). Surgery also appears to generate high health state utility and thus more QALYs. In sensitivity analyses, surgery appears to be a cost-effective treatment option for prolactinomas across a range of ages, medical/surgical costs, and medical/surgical response rates, except when surgical cure rates are ≤ 30%. Conclusion Our single institution analysis suggests that surgery may be a more cost-effective treatment for prolactinomas than medical management for a range of patient ages, costs, and response rates. Direct empirical comparison of QALYs for different treatment strategies is needed to confirm these findings.

The surgical treatment of acromegaly

PURPOSE

Surgical extraction of as much tumour mass as possible is considered the first step of treatment in acromegaly in many centers. In this article the potential benefits, disadvantages and limitations of operative acromegaly treatment are reviewed.

METHODS

Pertinent literature was selected to provide a review covering current indications, techniques and results of operations for acromegaly.

RESULTS

The rapid reduction of tumour volume is an asset of surgery. To date, in almost all patients, minimally invasive, transsphenoidal microscopic or endoscopic approaches are employed. Whether a curative approach is feasible or a debulking procedure is planned, can be anticipated on the basis of preoperative magnetic resonance imaging. The radicality of adenoma resection essentially depends on localization, size and invasive character of the tumour. The normalization rates of growth hormone and IGF-1 secretion, respectively, depend on tumour-related factors such as size, extension, the presence or absence of invasion and the magnitude of IGF-1 and growth hormone oversecretion. However, also surgeon-related factors such as experience and patient load of the centers have been shown to strongly affect surgical results and the rate of complications. As compared to most medical treatments, surgery is relatively cheap since the costs occur only once and not repeatedly. There are several new technical gadgets which aid in the surgical procedure: navigation and variants of intraoperative imaging.

CONCLUSIONS

For the mentioned reasons, current algorithms of acromegaly management suggest an initial operation, unless the patients are unfit for surgery, refuse an operation or only an unsatisfactory resection is anticipated. A few suggestions are made when a re-operation could be considered.

Advancing Treatment of Pituitary Adenomas through Targeted Molecular Therapies: The Acromegaly and Cushing Disease Paradigms

The current treatment of pituitary adenomas requires a balance of conservative management, surgical resection, and in select tumor types, molecular therapy. Acromegaly treatment is an evolving field where our understanding of molecular targets and drug therapies has improved treatment options for patients with excess growth hormone levels. We highlight the use of molecular therapies in this disease process and advances in this field, which may represent a paradigm shift for the future of pituitary adenoma treatment.

Outcome of radiotherapy for pituitary adenomas

AIM

The aim of this study was to analyze the outcome and toxicities and its correlation to patient related and treatment related factors.

BACKGROUND

Pituitary adenomas are treated by radiation therapy (RT) as one of the modalities along with surgery and medical therapy. RT to pituitary adenomas is a challenge due to adjacent dose limiting structures such as optic apparatus and hypothalamus.

MATERIALS AND METHODS

Between January 2004 and December 2010, 94 patients treated for pituitary adenoma with RT who had hospital records of a minimum follow-up of 1 year were included in the analysis. Tests of correlation were done with regards to treatment factors.

RESULTS

Male preponderance was noted in our patient population. Nonfunctioning and functioning tumors were equal in number in this series. Hypopituitarism was associated in 58.5% of patients prior to RT. Radiological tumor progression was seen in one patient (1/94) who had a nonfunctioning tumor. Among functioning tumors, biochemical remission was seen in 93.6% of patients at a median follow-up of 6 years.

CONCLUSIONS

Visual complication was seen in 5.3% of patients and worsening or new onset hypopituitarism was seen in 6.4%. Conventional 3-field technique was associated with significantly more visual complication compared to Stereotactic Radiation Therapy (SRT) technique. Doses ≤50.4 Gy showed a trend of reduced rate of visual and endocrine complications with no compromise in efficacy.

New therapeutic agents for acromegaly

The currently available somatostatin receptor ligands (SRLs) and growth hormone (GH) antagonists are used to control levels of GH and insulin-like growth factor 1 (IGF-1) in patients with acromegaly. However, these therapies are limited by wide variations in efficacy, associated adverse effects and the need for frequent injections. A phase III trial of oral octreotide capsules demonstrated that this treatment can safely sustain suppressed levels of GH and IGF-1 and reduce the severity of symptoms in patients with acromegaly previously controlled by injectable SRL therapy, with the added benefit of no injection-site reactions. Phase I and phase II trials of the pan-selective SRL DG3173, the liquid crystal octreotide depot CAM2029 and an antisense oligonucleotide directed against the GH receptor have shown that these agents can be used to achieve biochemical suppression in acromegaly and have favourable safety profiles. This Review outlines the need for new therapeutic agents for patients with acromegaly, reviews clinical trial data of investigational agents and considers how these therapies might best be integrated into clinical practice.

Neurosurgical Treatment of Acromegaly

Surgical removal of as much tumor mass as possible is usually considered the first step of treatment in acromegaly, unless the patients are unfit for surgery or refuse an operation. To date, in almost all cases, minimally invasive, transsphenoidal microscopic or endoscopic approaches are used. Whether a curative approach is feasible or a debulking procedure is planned, can be anticipated on the basis of preoperative magnetic resonance imaging. It mostly depends on localization, size, and the invasive character of the lesion. The surgical results depend on tumor-related factors such as size, extension, the presence or absence of invasion, and the magnitude of IGF-1 and growth hormone oversecretion, respectively. However, even surgeon-related factors such as experience and case load of the centers have been shown to strongly affect surgical results and complication rates. A reoperation can be considered at various stages in the treatment algorithm. There are several new technical gadgets which might aid in the surgical procedure: navigation, the Doppler probe, and variants of intraoperative imaging.

Multi-modal management of acromegaly: a value perspective

PURPOSE

The Acromegaly Consensus Group recently released updated guidelines for medical management of acromegaly patients. We subjected these guidelines to a cost analysis.

METHODS

We conducted a cost analysis of the recommendations based on published efficacy rates as well as publicly available cost data. The results were compared to findings from a previously reported comparative effectiveness analysis of acromegaly treatments. Using decision tree software, two models were created based on the Acromegaly Consensus Group's recommendations and the comparative effectiveness analysis. The decision tree for the Consensus Group's recommendations was subjected to multi-way tornado analysis to identify variables that most impacted the value analysis of the decision tree.

RESULTS

The value analysis confirmed the Consensus Group's recommendations of somatostatin analogs as first line therapy for medical management. Our model also demonstrated significant value in using dopamine agonist agents as upfront therapy as well. Sensitivity analysis identified the cost of somatostatin analogs and growth hormone receptor antagonists as having the most significant impact on the cost effectiveness of medical therapies.

CONCLUSION

Our analysis confirmed the value of surgery as first-line therapy for patients with surgically accessible lesions. Surgery provides the greatest value for management of patients with acromegaly. However, in accordance with the Acromegaly Consensus Group's recent recommendations, somatostatin analogs provide the greatest value and should be used as first-line therapy for patients who cannot be managed surgically. At present, the substantial cost is the most significant negative factor in the value of medical therapies for acromegaly.

Effective time window in reducing pituitary adenoma size by gamma knife radiosurgery

OBJECTIVES

Although the effectiveness of gamma knife radiosurgery (GKRS) in controlling the size of pituitary adenomas has been well demonstrated in many studies, the time period in which significant changes in tumor size occurs has been investigated in a limited fashion. It is important to determine the therapeutic window of GKRS in treating pituitary adenomas, i.e., the effective timeframe during which significant size reduction of these tumors occurs, so that alternative treatments such as further GKRS or microsurgery might be prescribed in a timely manner if clinically indicated.

METHODS

This was a nested sample of an ongoing local cohort study on GKRS for pituitary adenomas at the University of Virginia. Magnetic resonance imaging (MRI) using dedicated sequences was employed. Only patients with a baseline MRI (TP0) and at least 1 follow-up study performed in the University Hospital after GKRS were included. The follow-up scans were performed at five time-points (TP1-TP5) which were 6, 12, 24, 36 and 48 months after GKRS. The dimensional indices of the tumors were measured in three orthogonal planes, i.e., transverse (TR), antero-posterior (AP) and cranio-caudal (CC). The volumes of the tumors were estimated by using the following formula: [Formula: see text]. Tumor volume decrease by more than 25% from baseline was considered as 'shrinkage', <25% tumor size increase or decrease was considered 'static', and more than 25% increase as 'increment'. Our cohort consisted of 21 patients, with functioning adenomas in 13 subjects i.e. six adrenocorticotrophic hormone (ACTH)-secreting and seven growth hormone (GH)-secreting, and non-functioning (NF) adenomas in eight subjects.

RESULTS

In 26 adenomas (8 ACTH, 9 GH and 9 NF), tumor control (tumor shrinkage or static) were achieved in 21 tumors (80.8%); 89, 75, and 78% for GH-secreting, ACTH-secreting and NF adenomas respectively, at the end of the 4-year follow-up period. Analysis of variance showed significant differences of GKRS margin dose among different types of tumors (p = 0.013), but not of baseline tumor volumes (p = 0.240). Logistic regression analysis showed no significant association of margin dose, baseline volume or tumor type with the tumor control outcome. Comparison of tumor change using dimensional indices relative to the base time point (TP0) showed that in the sample there was an average reduction of 1.290 mm at TP1 (6 months) with p values 0.155 (parametric t test) and 0.098 (non-parametric Wilcoxon signed-ranked test) respectively, showing a moderate reduction in tumor dimensional indices. The change in dimensional indices at later time points (TP2-TP5) showed an average reduction ranging from 1.930 to 2.471 mm. Significant reduction in the mean dimensional indices was firstly observed at TP2 (1 year) with p values 0.013 (t test) and 0.018 (Wilcoxon signed-rank test). Such scale of reduction in the dimensional indices appeared to be maintained along the time axis (from TP2 to TP5).

CONCLUSIONS

Significant decrease in tumor dimensional indices tended to occur at 1 year post-GKRS. Although to a lesser extent, such decrease in dimensional indices continued up to the end of our follow-up period.

Cost-effectiveness analysis of two therapeutic schemes in the treatment of acromegaly: a retrospective study of 168 cases

PURPOSE

This study aimed to estimate the cost effectiveness of two therapeutic schemes, including preoperative medical therapy and surgery as primary therapy.

METHODS

A total of 168 acromegaly cases were retrospectively investigated for a comparative evaluation of surgery and preoperative medical therapy. A Markov model was developed to simulate treatment cost-effectiveness and progression of acromegaly.

RESULTS

Overall effectiveness of preoperative medical therapy was significantly higher than surgery in acromegalic patients with macroadenoma. In addition, life expectancy, and cost per life-year gained were slightly higher in the preoperative medical therapy group than in the initial surgery group when patients received surgery as a secondary treatment. Interestingly, preoperative medical therapy achieved a significant increase in life expectancy and reduced cost for patients who received long-term medical therapy as secondary treatment.

CONCLUSIONS

In acromegalic patients with macroadenoma, the cost-effectiveness analysis revealed more satisfactory outcomes in preoperative therapy, compared with primary surgery.

Safety and efficacy of oral octreotide in acromegaly: results of a multicenter phase III trial

BACKGROUND

A novel oral octreotide formulation was tested for efficacy and safety in a phase III, multicenter, open-label, dose-titration, baseline-controlled study in patients with acromegaly.

METHODS

We enrolled 155 complete or partially controlled patients (IGF-1 <1.3 × upper limit of normal [ULN], and 2-h integrated GH <2.5 ng/mL) receiving injectable somatostatin receptor ligand (SRL) for ≥ 3 months. Subjects were switched to 40 mg/d oral octreotide capsules (OOCs), and the dose escalated to 60 and then up to 80 mg/d to control IGF-1. Subsequent fixed doses were maintained for a 7-month core treatment, followed by a voluntary 6-month extension.

RESULTS

Of 151 evaluable subjects initiating OOCs, 65% maintained response and achieved the primary endpoint of IGF-1 <1.3 × ULN and mean integrated GH <2.5 ng/mL at the end of the core treatment period and 62% at the end of treatment (up to 13 mo). The effect was durable, and 85 % of subjects initially controlled on OOCs maintained this response up to 13 months. When controlled on OOCs, GH levels were reduced compared to baseline, and acromegaly-related symptoms improved. Of 102 subjects completing the core treatment, 86% elected to enroll in the 6-month extension. Twenty-six subjects who were considered treatment failures (IGF-1 ≥ 1.3 × ULN) terminated early, and 23 withdrew for adverse events, consistent with those known for octreotide or disease related.

CONCLUSIONS

OOC, an oral therapeutic peptide, achieves efficacy in controlling IGF-1 and GH after switching from injectable SRLs for up to 13 months, with a safety profile consistent with approved SRLs. OOC appears to be effective and safe as an acromegaly monotherapy.

Surgical treatment of prolactinomas: cons

Prolactinomas account for approximately 40 % of all pituitary adenomas. Over 95 % of prolactinomas are microadenomas (< 10 mm diameter). Treatment is indicated to correct hypogonadism, restore other hormonal deficits, and alleviate local mass effects. Dopamine agonists (DA) are highly effective in achieving these goals and are well-tolerated. The vast majority of prolactinomas will respond to conventional doses of cabergoline (≤2 mg/week) that do not carry an increased risk of cardiac valvular abnormalities. DA therapy may be successful withdrawn in a subset of patients and thus is not necessarily a lifelong commitment. Although transsphenoidal surgery (TSS) is an option for prolactinoma treatment, it is less effective than medical management, carries considerably more risk, and is more expensive. The benefit/risk ratio for DA therapy compared to TSS actually becomes increasingly more favorable as tumor size increases. Therefore DA should remain the clear treatment of choice for essentially all patients with prolactinomas, reserving TSS as a second-line option for the very small number of patients that do not tolerate or are completely resistant to DA therapy.

Patient-focussed outcomes in acromegaly

BACKGROUND

Health-related quality of life (QoL) is severely impaired in acromegaly due to the physical and psychological consequences of the disease. Pharmacological and surgical treatments, when available, can improve QoL and life expectancy.

CASE DESCRIPTION

A 34-year-old male with uncontrolled acromegaly due to a large and invasive macroadenoma, which could not be resected by transsphenoidal surgery. Over 9 years, he had limited access to pharmacological interventions and persisted with clinically and biochemically active disease, with severe co-morbidities and a poor QoL, which eventually lead to a premature sudden death.

CONCLUSION

This case highlights the impact that active acromegaly has when treatment resources are limited. We review the factors contributing to poor QoL in this disease, with special reference to the Latin American scenario.

Emerging drugs for acromegaly

INTRODUCTION

Acromegaly is a rare disease that severely impacts patients' health all the while, being a slowly progressing illness. In the past decades, advancements in treatment modalities, especially development of new drugs, as well as focused guidelines has improved management of acromegaly. Still, many patients are considered not sufficiently treated and there remains an ongoing need for further development.

AREAS COVERED

This article reviews new medical treatments currently under clinical investigation (such as pasireotide, oral octreotide and somatoprim) and under experimental development (such as octreotide implants, CAM2029 and ATL-1103).

EXPERT OPINION

As it seems unlikely that one single agent may achieve cure in 100% of cases, there is an urgent need for new agents that help patients where current medication fails. Imperatively, this means we have to improve our understanding of the underlying pathogenetic and molecular mechanisms.

Repeat endoscopic transsphenoidal surgery for acromegaly: remission and complications

Reported biochemical remission rates following surgical intervention for acromegaly range from 38 to 83%. In patients not achieving surgical remission, few options remain, mostly limited to medical management and radiation therapy. There is debate over whether or not to offer reoperation to patients in whom surgical remission is not achieved with initial resection. Retrospective chart review was undertaken to determine all patients having acromegaly with persistently elevated GH and/or IGF-1 levels after initial pituitary adenoma resection, and who underwent reoperation using endoscopic endonasal approach at a single institution. Biochemical remission was defined as a postoperative GH level <1 ng/mL and a normal postoperative IGF-1 level in the absence of any medical therapy. In total, 14 patients underwent repeat surgical intervention for acromegaly via endoscopic transsphenoidal approach. Of the 14 patients, 8 (57%) achieved biochemical remission following repeat surgical intervention. Lower preoperative GH levels were associated with greater chance of biochemical remission (P = 0.048). New endocrinopathies were seen in 2 patients (14%), and both were transient diabetes insipidus. Meningitis occurred in 2 patients (14%); both were aseptic meningitis with no sequelae. No mortality was encountered. Repeat surgical intervention for acromegaly via endoscopic transsphenoidal approach appears safe and effective. With no mortality and minimal morbidity, repeat surgical intervention via endoscopic transsphenoidal approach appears a reasonable option for these hard-to-treat patients and should be considered for patients in whom surgical remission is not achieved with initial surgery.

Pharmacoeconomic aspects of the treatment of pituitary gland tumours

Nowadays physicians are under economic pressure; therefore therapeutic decisions based on safety, efficacy, and the effectiveness of the medication also require economic analysis. The aim of this review is to discuss data concerning the cost-effectiveness of drug therapy in patients with hormonally active pituitary adenomas, namely growth hormone, adrenocorticotropic hormone, thyroid-stimulating hormone-secreting pituitary adenomas, prolactinoma and pituitary incidentaloma. In acromegalic patients using lanreotide is cheaper for health care payers and more convenient for physicians and patients because of the opportunity for self/partner injections, lower clogging risk and possibility of longer intervals between injections, while the efficacy is comparable with octreotide. Patients with prolactinomas should be treated with novel dopamine agonists, such as cabergoline or quinagolide, however, bromocriptine still remains a cheaper and almost as effective alternative. There are no easy methods or algorithms, but in general, extracting the maximum value from the investment in treatment is essential.

Long-term health-related quality of life of surgically treated pituitary adenoma patients: a descriptive study

Context. The literature concerning the health-related quality of life (HRQoL) of patients with surgically treated PA is controversial. Objective. To describe the long-term HRQoL of surgically treated patients in all PA classes. Design and subjects. The 15D, a generic HRQoL instrument producing a 15-dimensional profile and a single 15D index score (a difference ≥0.03 on a 0-1 scale is considered clinically important), was used to assess the HRQoL of a 13-year surgical cohort of PA patients in Northern Finland. Results and Conclusion. Nighty-eight eligible consecutive patients with surgically treated PA were studied at an average of 6.3 years after their latest pituitary operation. The average postoperative 15D profiles in patients with non-functioning PA and in acromegalics without GH-suppressive medical treatment were similar to those of the age-standardized general population. However, after this rather long followup, the mean 15D score and the number of statistically significant 15D dimension impairments, compared with those of their reference population, were 0.11 and 9/15, 0.10 and 3/15, and 0.08 and 7/15 for Cushing's disease, acromegalics needing somatostatin analog, and prolactinoma patients, respectively. Hypopituitarism with replacement medication was not associated with impaired HRQoL. The somatostatin-analog-associated HRQoL finding warrants further clinical research.