Preoperative Lanreotide Treatment Improves Outcome in Patients with Acromegaly Resulting from Invasive Pituitary Macroadenoma

Surgical and non-surgical interventions for primary and salvage treatment of growth hormone-secreting pituitary adenomas in adults

BACKGROUND

Growth hormone (GH)-secreting pituitary adenoma is a severe endocrine disease. Surgery is the currently recommended primary therapy for patients with GH-secreting tumours. However, non-surgical therapy (pharmacological therapy and radiation therapy) may be performed as primary therapy or may improve surgical outcomes.

OBJECTIVES

To assess the effects of surgical and non-surgical interventions for primary and salvage treatment of GH-secreting pituitary adenomas in adults.

SEARCH METHODS

We searched CENTRAL, MEDLINE, WHO ICTRP, and ClinicalTrials.gov. The date of the last search of all databases was 1 August 2022. We did not apply any language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs of more than 12 weeks' duration, reporting on surgical, pharmacological, radiation, and combination interventions for GH-secreting pituitary adenomas in any healthcare setting.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts for relevance, screened for inclusion, completed data extraction, and performed a risk of bias assessment. We assessed studies for overall certainty of the evidence using GRADE. We estimated treatment effects using random-effects meta-analysis. We expressed results as risk ratios (RR) for dichotomous outcomes together with 95% confidence intervals (CI) or mean differences (MD) for continuous outcomes, or in descriptive format when meta-analysis was not possible.

MAIN RESULTS

We included eight RCTs that evaluated 445 adults with GH-secreting pituitary adenomas. Four studies reported that they included participants with macroadenomas, one study included a small number of participants with microadenomas. The remaining studies did not specify tumour subtypes. Studies evaluated surgical therapy alone, pharmacological therapy alone, or combination surgical and pharmacological therapy. Methodological quality varied, with many studies providing insufficient information to compare treatment strategies or accurately judge the risk of bias. We identified two main comparisons, surgery alone versus pharmacological therapy alone, and surgery alone versus pharmacological therapy and surgery combined. Surgical therapy alone versus pharmacological therapy alone Three studies with a total of 164 randomised participants investigated this comparison. Only one study narratively described hyperglycaemia as a disease-related complication. All three studies reported adverse events, yet only one study reported numbers separately for the intervention arms; none of the 11 participants were observed to develop gallbladder stones or sludge on ultrasonography following surgery, while five of 11 participants experienced any biliary problems following pharmacological therapy (RR 0.09, 95% CI 0.01 to 1.47; 1 study, 22 participants; very low-certainty evidence). Health-related quality of life was reported to improve similarly in both intervention arms during follow-up. Surgery alone compared to pharmacological therapy alone may slightly increase the biochemical remission rate from 12 weeks to one year after intervention, but the evidence is very uncertain; 36/78 participants in the surgery-alone group versus 15/66 in the pharmacological therapy group showed biochemical remission. The need for additional surgery or non-surgical therapy for recurrent or persistent disease was described for single study arms only. Surgical therapy alone versus preoperative pharmacological therapy and surgery Five studies with a total of 281 randomised participants provided data for this comparison. Preoperative pharmacological therapy and surgery may have little to no effect on the disease-related complication of a difficult intubation (requiring postponement of surgery) compared to surgery alone, but the evidence is very uncertain (RR 2.00, 95% CI 0.19 to 21.34; 1 study, 98 participants; very low-certainty evidence). Surgery alone may have little to no effect on (transient and persistent) adverse events when compared to preoperative pharmacological therapy and surgery, but again, the evidence is very uncertain (RR 1.23, 95% CI 0.75 to 2.03; 5 studies, 267 participants; very low-certainty evidence). Concerning biochemical remission, surgery alone compared to preoperative pharmacological therapy and surgery may not increase remission rates up until 16 weeks after surgery; 23 of 134 participants in the surgery-alone group versus 51 of 133 in the preoperative pharmacological therapy and surgery group showed biochemical remission. Furthermore, the very low-certainty evidence did not suggest benefit or detriment of preoperative pharmacological therapy and surgery compared to surgery alone for the outcomes 'requiring additional surgery' (RR 0.48, 95% CI 0.05 to 5.06; 1 study, 61 participants; very low-certainty evidence) or 'non-surgical therapy for recurrent or persistent disease' (RR 1.22, 95% CI 0.65 to 2.28; 2 studies, 100 participants; very low-certainty evidence). None of the included studies measured health-related quality of life. None of the eight included studies measured disease recurrence or socioeconomic effects. While three of the eight studies reported no deaths to have occurred, one study mentioned that overall, two participants had died within five years of the start of the study.

AUTHORS' CONCLUSIONS

Within the context of GH-secreting pituitary adenomas, patient-relevant outcomes, such as disease-related complications, adverse events and disease recurrence were not, or only sparsely, reported. When reported, we found that surgery may have little or no effect on the outcomes compared to the comparator treatment. The current evidence is limited by the small number of included studies, as well as the unclear risk of bias in most studies. The high uncertainty of evidence significantly limits the applicability of our findings to clinical practice. Detailed reporting on the burden of recurrent disease is an important knowledge gap to be evaluated in future research studies. It is also crucial that future studies in this area are designed to report on outcomes by tumour subtype (that is, macroadenomas versus microadenomas) so that future subgroup analyses can be conducted. More rigorous and larger studies, powered to address these research questions, are required to assess the merits of neoadjuvant pharmacological therapy or first-line pharmacotherapy.

Preoperative medical treatments and surgical approaches for acromegaly: A systematic review

OBJECTIVE

Acromegaly is a condition characterized by an overproduction of growth hormone which infers high morbidity and mortality if left untreated. The objective of this review is to analyse and appraise the current evidence for the generalized use of preoperative medications and the various surgical approaches as described in the literature.

DESIGN

A thorough search from MEDLINE via PubMed, EMBASE, and Cochrane Library has been performed which identified a total of 37 papers.

CONCLUSION

The preoperative use of somatostatin receptor agonists (SAs) in acromegaly is a controversial topic with current guidelines suggesting against their generalized routine use. Most authors noticed an insignificant long-term remission of acromegaly when given SAs compared with nil preoperative therapy, except for invasive macroadenomas as SAs have been found to reduce the tumour volume and aid towards the total resection of the adenoma. Furthermore, according to the evidence available, endoscopic transsphenoidal surgery is the optimum method for hypophysectomy in terms of its remission and safety profile.

[Predictors of postoperative remission of acromegaly. (Experience of the Burdenko Neurosurgical Center)]

BACKGROUND

Treatment of acromegaly is still an unresolved problem. Overall postoperative remission rate ranges from 34 to 85%. These values are better for microadenomas (75-90%) and worse for macroadenomas (45-70%). Identification of predictors of acromegaly remission after surgical treatment is an urgent objective to improve the quality of medical care for these patients.

OBJECTIVE

To analyze postoperative freedom from acromegaly and predictors of remission.

MATERIAL AND METHODS

A retrospective single-center study included 227 patients with acromegaly who underwent resection of pituitary adenoma between August 2018 and August 2021.

RESULTS

Remission (normalization of serum IGF-1) was achieved in 65 (55%) patients. Growth hormone and IGF-1 index decreased after surgery in all patients. Mean preoperative serum growth hormone was 12.45 [6.88, 29.85] ng/ml, early postoperative concentration - 1.54 [0.80, 3.38] ng/ml, in delayed period - 1.15 [0.57, 3.80] ng/ml. Mean IGF-1 index was 2.18 [1.69, 2.71], 1.47 [0.99, 1.90] and 0.99 [0.74, 1.43], respectively.

CONCLUSION

Significant predictors of acromegaly remission after neurosurgical treatment were age, preoperative level of growth hormone, tumor size and location, growth hormone and IGF-1 index in early postoperative period and residual tumor after surgery. Multivariate analysis revealed a significant association of acromegaly remission with small tumor size, low postoperative level of growth hormone and no residual tumor within 3-6 month after surgery.

Cost-effectiveness of direct surgery versus preoperative octreotide therapy for growth-hormone secreting pituitary adenomas

PURPOSE

The objective of this study was to compare the cost-effectiveness of preoperative octreotide therapy followed by surgery versus the standard treatment modality for growth-hormone secreting pituitary adenomas, direct surgery (that is, surgery without preoperative treatment) from a public third-party payer perspective.

METHODS

We developed an individual-level state-transition microsimulation model to simulate costs and outcomes associated with preoperative octreotide therapy followed by surgery and direct surgery for patients with growth-hormone secreting pituitary adenomas. Transition probabilities, utilities, and costs were estimated from recent published data and discounted by 3% annually over a lifetime time horizon. Model outcomes included lifetime costs [2020 United States (US) Dollars], quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICERs).

RESULTS

Under base case assumptions, direct surgery was found to be the dominant strategy as it yielded lower costs and greater health effects (QALYs) compared to preoperative octreotide strategy in the second-order Monte Carlo microsimulation. The ICER was most sensitive to probability of remission following primary therapy and duration of preoperative octreotide therapy. Accounting for joint parameter uncertainty, direct surgery had a higher probability of demonstrating a cost-effective profile compared to preoperative octreotide treatment at 77% compared to 23%, respectively.

CONCLUSIONS

Using standard benchmarks for cost-effectiveness in the US ($100,000/QALY), preoperative octreotide therapy followed by surgery may not be cost-effective compared to direct surgery for patients with growth-hormone secreting pituitary adenomas but the result is highly sensitive to initial treatment failure and duration of preoperative treatment.

Preoperative Medical Treatment for Patient with Acromegaly: yes or no?

Transsphenoidal surgery is the first-line treatment for acromegaly. However, several factors can modify surgical remission rates, such as the initial hormone levels, the size and invasiveness of the tumor, and the degree of experience of the surgeon. Physicians treating patients with acromegaly should thus consider how to improve surgical remission rates. As stated in recent guidelines, the major point is to consider that any patient with acromegaly should be referred to an expert neurosurgeon to maximize the chances of surgical sure. The benefits of presurgical medical treatment, mainly using somatostatin receptor ligands (SRLs), given 3 to 6 months before surgery, remain controversial. By normalizing growth hormone and insulin-like growth factor 1 levels, SRLs may improve the overall condition of the patient, thus decreasing anesthetic and surgical complications. By decreasing the tumor size and modifying the consistency of the tumor, SRLs might also make surgical excision easier. This is however theoretical as published data are contradictory on both points, and only limited data support the use of a systematical presurgical medical treatment. The aim of this review is to analyze the potential benefits and pitfalls of using presurgical medical treatment in acromegaly in view of the contradictory literature data. We also attempt to determine the profile of patients who might most benefit from this presurgical medical treatment approach as an individualized therapeutic management of acromegaly.

Efficacy of lanreotide 120 mg primary therapy on tumour shrinkage and ophthalmologic symptoms in acromegaly after 1 month

INTRODUCTION

Few studies have attempted to evaluate the early efficacy of first-generation somatostatin analogues in somatotroph macroadenomas.

OBJECTIVE

To investigate the short-term efficacy of primary therapy with lanreotide 120 mg at 1 and 3 months on tumour shrinkage and ophthalmologic symptoms in newly diagnosed patients with acromegaly.

DESIGN AND PATIENTS

This single-centre retrospective study included 21 patients with de novo acromegaly resulting from pituitary macroadenoma, with optic chiasm compression (Grade ≤ 2) and/or cavernous sinus invasion, treated with a monthly injection of lanreotide 120 mg. Clinical, hormonal, ophthalmologic and magnetic resonance imaging scan evaluations were conducted after the first and the third months of treatment.

RESULTS

Tumour volume reduction was more pronounced at 1 month; mean volume change: -31.4 ± 19.5%, p < .0001 than between the first and third month of treatment; mean volume reduction: -20.6 ± 13.4%, p = .0009. The mean volume change between baseline and the third month was - 46.4 ± 21.6, (p < .0001). A significant volume reduction (≥25%) was observed in 61.9% of individuals (13/21) at the first month. Among 14 individuals with optic chiasm compression and visual field defects, visual field normalization or improvement were observed in seven cases (50%), stabilization in four cases (28.5%), and mild worsening in three cases (21.4%) at 1 month. The decrease in growth hormone and IGF-1 serum values was significant at 1 month.

CONCLUSIONS

Primary treatment with lanreotide 120 mg in patients with somatotroph macroadenomas provides early significant tumour shrinkage with rapid improvement of visual symptoms at the end of the first month in 50% of patients.

Personalized Medical Treatment in Patients with Acromegaly: A Review

Acromegaly is associated with significant morbidity and mortality if not appropriately treated. In addition to insulin-like growth factor 1 (IGF-1) and growth hormone (GH) normalization, and tumor shrinkage, treatment goals include symptom relief, managing complications and improving quality of life. Surgical resection is a first-line treatment in most patients, with few being pretreated pre-operatively with medications. Somatostatin receptor ligands (SRLs), injectable and more recently oral capsules, have been the cornerstone of first-line medical therapy for persistent disease. However, several factors, including sparsely granulated adenomas, absent/low somatostatin receptor (SSTR2) status, imaging T2-hyperintensity, young age and aryl hydrocarbon receptor interacting protein mutations could predict first-generation SRL resistance. Patients with these characteristics may be better candidates for the GH receptor antagonist, pegvisomant, or in cases of large tumors the second-generation SRL, pasireotide. Combination therapy should be further pursued in patients who remain biochemically uncontrolled or have high remnant tumor after monotherapy. An efficacious and cost-effective pegvisomant dose-sparing effect of SRLs when used in combination has been demonstrated. With such a wide array of medical treatment options, it is increasingly important to tailor treatment to patients' unique characteristics as well as preferences, with a goal of personalizing management to achieve high quality outcomes.

Clinical relevance of tumor consistency in pituitary adenoma

PURPOSE

To review the clinical relevance of pituitary adenoma (PA) consistency and its relationship to clinical presentation, radiologic and histopathological characteristics, and surgical outcomes.

BACKGROUND

PA consistency is a critical factor influencing operative planning, surgical outcomes, and patient counseling. There is no validated classification of PA consistency in the literature, and there are no current preoperative variables capable of predicting it.

REVIEW

We conducted a thorough literature review of the Medline, Embase, Web of Science, and Cochrane Library databases. The inclusion criteria were all articles that described PA consistency and correlated it with preoperative aspects, radiological, pathological, and operative findings, or clinical outcomes.

DISCUSSION

Although most authors differentiate easily aspirated (soft) tumors from those that are not (fibrous, might require prior fragmentation), there is no universally accepted PA consistency classification. Fibrous PA tends to be hypointense on T2WI and has lower apparent diffusion coefficient (ADC) values. Fibrous tumors seemed to present higher invasion into neighboring structures, including the cavernous sinus. Several articles suggest that dopamine agonists could increase PA consistency and that prior surgery and radiotherapy also make PA more fibrous. The anatomopathological studies identify collagen as being mainly responsible for fibrous consistency of adenomas.

CONCLUSIONS

Preoperative knowledge of PA consistency affords the neurosurgeon substantial benefit, which clearly appears to be relevant to surgical planning, risks, and surgery outcomes. It could also encourage the centralization of these high complexity tumors in reference centers. Further studies may be enhanced by applying standard consistency classification of the PA and analyzing a more extensive and prospective series of fibrous PA.

Somatostatin Analogs in Clinical Practice: a Review

Somatostatin analogs are an invaluable therapeutic option in the diagnosis and treatment of somatotropinomas, thyrotropinomas, and functioning and non-functioning gastroenteropancreatic neuroendocrine tumors. They should also be considered an effective and safe therapeutic alternative to corticotropinomas, gonadotropinomas, and prolactinomas resistant to dopamine agonists. Somatostatin analogs have also shown to be useful in the treatment of other endocrine diseases (congenital hyperinsulinism, Graves’ orbitopathy, diabetic retinopathy, diabetic macular edema), non-endocrine tumors (breast, colon, prostate, lung, and hepatocellular), and digestive diseases (chronic refractory diarrhea, hepatorenal polycystosis, gastrointestinal hemorrhage, dumping syndrome, and intestinal fistula).

Italian Association of Clinical Endocrinologists (AME) and Italian AACE Chapter Position Statement for Clinical Practice: Acromegaly - Part 2: Therapeutic Issues

Any newly diagnosed patient should be referred to a multidisciplinary team experienced in the treatment of pituitary adenomas. The therapeutic management of acromegaly always requires a personalized strategy. Normal age-matched IGF-I values are the treatment goal. Transsphenoidal surgery by an expert neurosurgeon is the primary treatment modality for most patients, especially if there are neurological complications. In patients with poor clinical conditions or who refuse surgery, primary medical treatment should be offered, firstly with somatostatin analogs (SSAs). In patients who do not reach hormonal targets with first-generation depot SSAs, a second pharmacological option with pasireotide LAR or pegvisomant (alone or combined with SSA) should be offered. Irradiation could be proposed to patients with surgical remnants who would like to be free from long-term medical therapies or those with persistent disease activity or tumor growth despite surgery or medical therapy. Since the therapeutic tools available enable therapeutic targets to be achieved in most cases, the challenge is to focus more on the quality of life.

Preoperative Somatostatin Analogues in Patients with Newly-diagnosed Acromegaly: A Systematic Review and Meta-analysis of Comparative Studies

Biochemical remission after transsphenoidal surgery is still unsatisfied in acromegaly patients with macroadenomas, especially with invasive macroadenomas. Concerning the impact of preoperative somatostatin analogues (SSAs) on surgical outcomes, previous studies with limited cases reported conflicting results. To assess current evidence of preoperative medical treatment, we performed a systematic review and meta-analysis of comparative studies. A literature search was conducted in Pubmed, Embase, and the Cochrane Library. Five randomized controlled trials (RCT) and seven non-RCT comparative studies were included. These studies mainly focused on pituitary macroadenomas though a small number of microadenoma cases were included. For safety, preoperative SSAs were not associated with elevated risks of postoperative complications. With respect to efficacy, the short-term cure rate was improved by preoperative SSAs, but the long-term cure rate showed no significant improvement. For invasive macroadenomas, the short-term cure rate was also improved, but the long-term results were not evaluable in clinical practice because adjuvant therapy was generally required. In conclusion, preoperative SSAs are safe in patients with acromegaly, and the favorable impact on surgical results is restricted to the short-term cure rate in macroadenomas and invasive macroadenomas. Further well-designed RCTs to examine long-term results are awaited to update the finding of this meta-analysis.

The effects of pre-operative somatostatin analogue therapy on treatment cost and remission in acromegaly

PURPOSE

To investigate the effects of preoperative somatostatin analogue (SSA) treatment on the annual cost of all acromegaly treatment modalities and on remission rates.

METHODS

The medical records of 135 patients with acromegaly who were followed at endocrinology clinic of Cerrahpasa Medical Faculty for at least 2 years after surgery between 2009 and 2016 were reviewed.

RESULTS

The mean follow-up time was 50.9 ± 25.7 months. Early remission was defined according to 3rd month values in patients who didn't achieve remission, and 6th month values in patients who achieved remission at the 3rd month after surgery. The early and late remission rates of the entire study population were 40% and 80.7%, respectively. The early remission of the preoperative SSA-treated group (61.5%) was significantly higher than SSA-untreated group (31.2%) (p = 0.002). The early remission of the preoperative SSA-treated patients with macroadenomas (52.2%) was also significantly higher than the SSA-untreated group (23.5%) (p = 0.02). In the subgroup analysis; this difference was much more pronounced in invasive macroadenomas (p = 0.002). There were no differences between the groups in terms of late remission.The median annual cost of all acromegaly treatment modalities in study population was €3788.4; the cost for macroadenomas was significantly higher than for microadenomas (€4125.0 vs. €3226.5, respectively; p = 0.03). Preoperative SSA use in both microadenomas and macroadenomas didn't alter the cost of treatment. The increase in the duration of preoperative medical treatment had no effect on early or late remissions (p = 0.09; p = 0.8).

CONCLUSIONS

Preoperative medical treatment had no effect on the costs of acromegaly treatment. There was a benefical effect of pre-operative SSA use on early remission in patients with macroadenomas; however, this effect didn't persist long term.

Pre-surgical medical treatment, a major prognostic factor for long-term remission in acromegaly

PURPOSE

To determine whether pre-surgical medical treatment (PSMT) using long-acting Somatostatin analogues in acromegaly may improve long-term surgical outcome and to determine decision making criteria.

METHODS

This retrospective study included 110 consecutive patients newly diagnosed with acromegaly, who underwent surgery in a reference center (Marseille, France). The mean long-term follow-up period was 51.4 ± 36.5 (median 39.4) months. Sixty-four patients received PSMT during 3-18 (median 5) months before pituitary surgery. Remission was defined at early (3 months) evaluation and at last follow-up by GH nadir after oral glucose tolerance test < 0.4 µg/L and normal IGF-1.

RESULTS

Pretreated and non-pretreated groups were comparable for the main confounding factors except for higher IGF-1 at diagnosis in PSMT patients. Remission rates were significantly different in pretreated or not pretreated groups (61.1% vs. 36.6%, respectively at long-term evaluation). In multivariate analysis, PSMT was significantly linked to 3 months (p < 0.01) and long-term remission (p < 0.01). Duration of PSMT was not significantly different in cured or non-cured patients, at both evaluation times. PSMT appeared to be more beneficial for patients with an invasive tumor. No patient with a tumor greater than 18 mm or mean GH level exceeding 35 ng/mL at diagnosis was cured by surgery alone (vs. 8 and 9 patients in the pretreated group, respectively). Patients with PSMT showed more transient mild hyponatremia after surgery.

CONCLUSIONS

PSMT significantly improved short and long-term remission in patients with acromegaly, independent of its duration, especially in invasive adenomas.

Updates in Diagnosis and Treatment of Acromegaly

Acromegaly is a rare disease, caused largely by a growth hormone (GH) pituitary adenoma. Incidence is higher than previously thought. Due to increased morbidity and mortality, if not appropriately treated, early diagnosis efforts are essential. Screening is recommended for all patients with clinical features of GH excess. There is increased knowledge that classical diagnostic criteria no longer apply to all, and some patients can have GH excess with normal GH response to glucose. Treatment is multifactorial and personalised therapy is advised.

How are growth hormone and insulin-like growth factor-1 reported as markers for drug effectiveness in clinical acromegaly research? A comprehensive methodologic review

OBJECTIVE

In rare disease research, most randomized prospective clinical trials can only use limited number of patients and are comprised of highly heterogeneous populations. Therefore, it is crucial to report the results in such a manner that it allows for comparison of treatment effectiveness and biochemical control between studies. The aim of this review was to investigate the current methods that are being applied to measure and report growth hormone (GH) and insulin-like growth factor-1 (IGF-1) as markers for drug effectiveness in clinical acromegaly research.

SEARCH STRATEGY

A systematic search of recent prospective and retrospective studies, published between 2012 and 2017, that studied the effects of somatostatin analogues or dopamine agonists in acromegaly patients was performed. The markers of interest were GH, IGF-1, and the suppression of GH after an oral glucose tolerance test (OGTT). Additionally, the use of pharmacokinetic (PK) measurements in these studies was analyzed. The sampling design, cut-off for biochemical control, reported units, and used summary statistics were summarized.

RESULTS

A total of 49 articles were selected out of the 263 screened abstracts. IGF-1 concentrations were measured in all 49 studies, GH in 45 studies, and an OGTT was performed in 11 studies. A wide range of different cut-off values and sampling designs were used to determine biochemical control in acromegaly patients. The summary statistics were reported in various ways, with the percentage of biochemical control most frequently used. Nine studies sampled the PK at one or more time points. Non-compartmental analyses were commonly performed on the available PK data.

CONCLUSIONS

The way GH and IGF-1 are measured and reported in acromegaly research varies considerably. A consensus on how to report study results would enable better comparisons between studies, thereby improving evidence based decision making to optimize treatment in acromegaly.

Microsurgical versus endoscopic transsphenoidal resection for acromegaly: a systematic review of outcomes and complications

PURPOSE

The aim of this systematic review is to evaluate the long-term endocrine outcomes and postoperative complications following endoscopic vs. microscopic transsphenoidal resection (TSR) for the treatment of acromegaly.

METHODS

A literature review was performed, and studies with at least five patients who underwent TSR for acromegaly, reporting biochemical remission criteria and long-term remission outcomes were included. Data extracted from each study included surgical technique, perioperative complications, biochemical remission criteria, and long-term remission outcomes.

RESULTS

Fifty-two case series from 1976 to 2016 met the inclusion criteria, comprising 4375 patients. Thirty-six reports were microsurgical (n = 3144) and 13 were endoscopic (n = 940). Three studies compared microsurgical (n = 111) to endoscopic TSR outcomes (n = 180). The overall initial and long-term remission rates were 58.2 vs. 57.4% and 69.2 vs. 70.2% for the microsurgical and endoscopic groups, respectively. For microadenomas, the initial and long-term remission rates were 77.6 vs. 82.2% and 76.9 vs. 73.5% for microsurgical and endoscopic approaches, respectively. For macroadenomas, the initial and long-term remission rates were 46.9 vs. 60.0% and 40.2 vs. 61.5% for microsurgical and endoscopic approaches, respectively. The rates of postoperative CSF leak were 3.0 vs. 2.3% for the microscopic and endoscopic groups, respectively. The rates of hypopituitarism and transient diabetes insipidus were 6.7 vs. 6.4% and 9.0 vs. 7.8% for the microscopic and endoscopic groups, respectively.

CONCLUSIONS

Both endoscopic and microsurgical approaches for TSR of growth hormone-secreting adenomas are viable treatment options for patients with acromegaly, and yield similarly high rates of remission under the most current consensus criteria.

Prolonged preoperative treatment of acromegaly with Somatostatin analogs may improve surgical outcome in patients with invasive pituitary macroadenoma (Knosp grades 1-3): a retrospective cohort study conducted at a single center

BACKGROUND

This study aimed to investigate preoperative somatostatin analogs (SSAs) treatment on the surgical outcome in patients with acromegaly.

METHODS

An analysis of 358 patients with acromegaly was conducted. The preoperative medical therapy group (81 patients) received SSA treatment for at least 3 months prior to surgery, while the primary surgery group (277 patients) underwent transsphenoidal surgery directly. Follow-up duration was ≥3 months. Tumor invasion was evaluated by magnetic resonance imaging (MRI) and classified according to the Knosp grading system.

RESULTS

Most patients were diagnosed with macroadenoma. Among all patients (Knosp grades 0-4), preoperative SSA therapy did not significantly improve the curative effect of surgery, according to the levels of growth hormone (GH) and/or insulin-like growth factor 1 (IGF-1) markers. In patients with macroadenoma (Knosp grades 1-3), the remission rates were significantly higher in the SSA group compared to the surgery group when considering GH (56.4% vs. 37.3%, P = 0.048) and IGF-1 (43.2% vs. 17.6%, P = 0.004). In the preoperative medical therapy group, long-term use of SSAs (>6 months) led to higher remission rates (GH, 72.2% vs. 51.0%; and IGF-1, 61.1% vs. 29.8%; P = 0.12 and 0.02, respectively].

CONCLUSIONS

The long-term preoperative SSAs treatment may improve the surgical curative rate in acromegalic patients with invasive macroadenomas (Knosp grades 1-3).

MicroRNA-145 inhibits the activation of the mTOR signaling pathway to suppress the proliferation and invasion of invasive pituitary adenoma cells by targeting AKT3 in vivo and in vitro

Purpose

This study was designed to explore how miR-145 regulates the mTOR signaling pathway in invasive pituitary adenoma (IPA) by targeting AKT3.

Methods

A total of 71 cases of IPA tissues and 66 cases of non-IPA tissues were obtained in this study. In vitro, the IPA cells were assigned into blank control, empty plasmid, miR-145 mimic, miR-145 inhibitor, miR-145 mimic + rapamycin, miR-145 inhibitor + rapamycin and rapamycin groups. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were performed to detect the protein expressions of PI3K, AKT3, mTOR mRNA and the mRNA expression of miR-145 both in vivo and in vitro. Additionally, the S6K and RPS6 mRNA and protein expressions as well as the relative phosphorylation levels were determined in vitro. MTT assay, flow cytometry and transwell assay were used to testify the cell proliferation, apoptosis and invasion ability, respectively.

Results

The IPA tissues exhibited significantly lower expression of miR-145 but higher PI3K, AKT3 and mTOR mRNA and protein expressions when compared with the non-IPA tissues. Compared with the blank control and empty plasmid groups, the miR-145 mimic group showed significantly decreased PI3K, AKT3, mTOR, S6K and RPS6 mRNA and protein expressions as well as phosphorylation levels; besides, the IPA cell proliferation, migration and invasion ability were strongly inhibited, accompanied with the increased number of apoptotic cells. In the miR-145 inhibitor group, the PI3K, AKT3, mTOR, S6K and RPS6 mRNA and protein expressions as well as the phosphorylation levels were significantly increased; cell proliferation, migration and invasion ability were remarkably elevated, accompanied with reduced apoptotic cell number.

Conclusion

The study demonstrates that miR-145 inhibits the mTOR signaling pathway to suppress the IPA cell proliferation and invasion and promotes its apoptosis by targeting AKT3.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND AMERICAN COLLEGE OF ENDOCRINOLOGY DISEASE STATE CLINICAL REVIEW: MANAGEMENT OF ACROMEGALY PATIENTS: WHAT IS THE ROLE OF PRE-OPERATIVE MEDICAL THERAPY?

OBJECTIVE

Acromegaly is a complex disease characterized by growth hormone (GH) excess originating in most cases from a pituitary tumor. The goals of treatment include removing the tumor or reducing tumor burden, normalizing GH secretion and insulin-like growth factor 1 levels, and preserving normal pituitary function if possible. Surgery by an experienced neurosurgeon is still considered first-line therapy, especially in cases with small tumors. In the last few decades, significant progress in the development of selective pharmacologic agents has greatly facilitated the management of active acromegaly, with agents such as somatostatin-receptor ligands (SRLs), GH-receptor antagonists, and dopamine agonists. In addition to adjuvant treatment, pre-operative medical therapy and primary therapy in de novo patients are increasingly employed.

METHODS

A United States National Library of Medicine PubMed search (through July 2014) was conducted for the following terms: acromegaly, pre-operative medical therapy, somatostatin-receptor ligands, and somatostatin analogs. Articles not in English and those not in peer-reviewed journals were excluded. In reviewing pertinent articles, focus was placed on biochemical and other postoperative outcomes of medical therapy.

RESULTS

An analysis of the full effect of pre-operative use of SRLs on surgical outcomes (remission rates and peri-operative complications) is limited by heterogeneity of methodology, low overall surgical cure rates, and different study designs. The assumption that SRL use prior to surgery reduces peri-operative surgical risk has yet to be proven. A variable degree of tumor shrinkage with preoperative SRLs is observed. Likewise, SRL treatment 3 months before surgery may improve surgical remission rates in the short term; however, positive results do not persist in the long term.

CONCLUSION

We consider that medical therapy before surgery could play a role in carefully selected patients, but treatment should be individualized. Primary medical therapy with a SRL may be considered in patients with macroadenomas without local mass effects on the optic chiasm, as SRLs have been shown to reduce tumor size and control GH hypersecretion. However, the data are insufficient to support general use of a SRL prior to surgery in order to improve post-surgery biochemical outcomes. Theoretically, patients with severe cardiac and respiratory complications due to acromegaly could potentially benefit from pre-operative SRLs in order to reduce peri-operative morbidity. Further investigation and investment in large randomized long-term clinical trials are needed to define the precise role and duration of pre-surgical medical treatment in acromegaly patients.

Pros and cons in endocrine practice: pre-surgical treatment with somatostatin analogues in acromegaly

The aim of this commentary is to balance the pros and cons for pre-surgical SSA treatment in a modern perspective ending up with a pragmatic recommendation for treatment based on the current evidence and expertise of the authors. Even though prospective and randomized studies in this particular area are hampered by obvious limitations, the interpretation of the four published trials has in general been in favor of pre-treatment with SSA, showing a better outcome following surgery. However, major drawbacks of these studies, such as non-optimal diagnostic criteria for cure, potential selection bias, and timing of the postoperative evaluation in SSA pre-treated patients, limit their overall interpretation. Three matched-controlled studies showed remarkably similar results with no apparent beneficial effect of SSA pre-treatment on surgical outcome. Both prospective, randomized studies and retrospective studies did not find any significant difference in the rate of endocrine and non-endocrine complications related to surgery, despite the beneficial clinical effects of SSA treatment in most acromegalic patients. The newly diagnosed patient with acromegaly should be carefully evaluated in the trans-disciplinary neuroendocrine team and treatment individualized accordingly. The issue of SSA pre-treatment to improve surgical outcome is yet to be settled and further methodologically sound studies are probably necessary to clarify this point.

Serial follow-up of presurgical treatment using pasireotide long-acting release with or without octreotide long-acting release for naïve active acromegaly

The aim of the present study was to evaluate the serial changes of GH and IGF-1 in seven patients with naïve, active acromegaly following presurgical treatment of the somatostatin analog pasireotide long-acting release (LAR) and octreotide LAR. The patients were treated with pasireotide LAR with or without octreotide LAR for two years and underwent transsphenoidal adenomectomy. After treatment with the somatostatin analogs, the surgical cure rate was similar to that in patients who underwent transsphenoidal surgery alone. Diabetes insipidus was not identified in any patients after the operation. Pasireotide LAR was effective on GH as well as IGF-1 suppression and tumor size decreasing when used as the primary therapy. Future large-population studies to investigate the surgical curative rate after presurgical treatment with somatostatin analogs in patients with acromegaly and macroadenomas close to the cavernous sinus are warranted. However, that hyperglycemia developed following pre-surgical treatment with pasireotide should take into consideration.

Preoperative octreotide therapy and surgery in acromegaly: associations between glucose homeostasis and treatment response

In acromegaly, high GH/IGF-1 levels associate with abnormal glucose metabolism. Somatostatin analogs (SSAs) reduce GH and IGF-1 but inhibit insulin secretion. We studied glucose homeostasis in de novo patients with acromegaly and changes in glucose metabolism after treatment with SSA and surgery. In this post hoc analysis from a randomized controlled trial, 55 de novo patients with acromegaly, not using antidiabetic medication, were included. Before surgery, 26 patients received SSAs for 6 months. HbA1c, fasting glucose, and oral glucose tolerance test were performed at baseline, after SSA pretreatment and at 3 months postoperative. Area under curve of glucose (AUC-G) was calculated. Glucose homeostasis was compared to baseline levels of GH and IGF-1, change after SSA pretreatment, and remission both after SSA pretreatment and 3 months postoperative. In de novo patients, IGF-1/GH levels did not associate with baseline glucose parameters. After SSA pretreatment, changes in GH/IGF-1 correlated positively to change in HbA1c levels (both p < 0.03). HbA1c, fasting glucose, and AUC-G increased significantly during SSA pretreatment in patients not achieving hormonal control (all p < 0.05) but did not change significantly in patients with normalized hormone levels. At 3 months postoperative, HbA1c, fasting glucose, and AUC-G were significantly reduced in both cured and not cured patients (all p < 0.05). To conclude, in de novo patients with acromegaly, disease activity did not correlate with glucose homeostasis. Surgical treatment of acromegaly improved glucose metabolism in both cured and not cured patients, while SSA pretreatment led to deterioration in glucose homeostasis in patients not achieving biochemical control.

Surgery induced hypopituitarism in acromegalic patients: a systematic review and meta-analysis of the results

PURPOSE

Hypopituitarism is a possible complication of the surgical treatment of acromegaly. However, there is a wide variability in the incidence rates of surgery-induced hypopituitarism. The purpose of this study was the systematic collection and synthesis of information on the incidence rates of hypopituitarism, panhypopituitarism, specific axis deficiencies and diabetes insipidus after surgery for acromegaly treatment.

METHODS

We systematically reviewed all the papers that have reported pituitary deficits after surgery for acromegaly published up until December 2014, in the PubMed database. We identified 92 studies enrolling 6988 patients. A meta-analysis was performed to evaluate the incidence rates. We also performed several subgroup analyses to evaluate the impact of both surgical technique, and treatment prior to surgery, on the results.

RESULTS

The weighted incidence rates were 12.79 % for hypopituitarism (95 % CI 9.88-16.00 %), 2.50 % for panhypopituitarism (95 % CI 1.24-4.15 %), 6.50 % for ACTH deficiency (95 % CI 4.07-9.44 %), 4.39 % for TSH deficiency (95 % CI 2.99-6.04 %), 6.70 % for FSH/LH deficiency (95 % CI 3.89-10.17 %), 14.95 % for GH deficiency (95 % CI 7.25-24.64 %), 10.05 % for transient (95 % CI 7.18-13.33 %) and 2.42 % for permanent diabetes insipidus (95 % CI 1.70-3.27 %).

CONCLUSION

Our study provides new data on the incidence rates of hypopituitarism, specific pituitary axis deficiencies and diabetes insipidus after surgical treatment of acromegaly. Somatotroph function appears to be more prone to deficit than the other axes. However, there is a high heterogeneity between studies and several factors may influence the incidence of hypopituitarism.

Cost-effectiveness analysis of preoperative treatment of acromegaly with somatostatin analogue on surgical outcome

CONTEXT

There is no uniform standard of care for acromegaly. Due to the high costs involved, steps must be taken to ensure the cost-effective delivery of treatment.

OBJECTIVE

Taking the results of an earlier meta-analysis as a starting point, this study aims to determine whether treatment with long-acting somatostatin analogue (SSA) prior to surgery improves the cost-effectiveness of the treatment of acromegaly.

METHODS

The results are presented as an Incremental Cost Effectiveness Ratio (ICER) immediately after surgery, for the following year and over the next four decades. The cure rates percentage (95% CI) for the three randomized prospective controlled trials were 44.4% (34.2-54.7) and 18.2% (10.1-26.3) for preoperative treated and untreated patients respectively. The cost of pharmacological treatments was based on the number of units prescribed, dose and length of treatment.

RESULTS

The mean (95% CI) ICER immediately after surgery was €17,548 (12,007-33,250). In terms of the postoperative SSA treatment, the ICER changes from positive to negative before two years after surgery. One decade after surgery the ICER per patient/year was €-9973 (-18,798; -6752) for postoperative SSA treatment and €-31,733 (-59,812; -21,483) in the case of postoperative pegvisomant treatment.

CONCLUSIONS

In centres without optimal surgical results, preoperative treatment of GH-secreting pituitary macroadenomas with SSA not only shows a significant improvement in the surgical results, but is also highly cost-effective, with an ICER per patient/year one decade after surgery, of between €-9973 (-18,798; -6752) and €-31,733 (-59,812; -21,483) for SSA and pegvisomant respectively.

Preoperative somatostatin analogues versus direct transsphenoidal surgery for newly-diagnosed acromegaly patients: a systematic review and meta-analysis using the GRADE system

Whether the preoperative use of somatostatin analogues (SA) improves surgical outcomes in acromegaly is still a matter of debate.

OBJECTIVE

We conducted a systematic review of randomized, controlled trials that compared the short-term outcomes of preoperative use of SA (Pre-SA) with direct TSS (No-SA) for the treatment of newly diagnosed acromegaly.

METHODS

Embase, Pubmed, Lilacs, and Central Cochrane were used as our data sources. The primary outcomes were no need for any adjuvant treatment 3 months after surgery, based on biochemical results (GH nadir after OGTT <1 μg/L and normal IGF-1 for age and gender), quality of life and mortality. The included trials were analyzed using the Grading of Recommendations Assessment, Development, and Evaluation approach.

RESULTS

A total of 2.099 references were identified and two reviewers independently screened the titles and abstracts. From the 14 potentially eligible studies, four were included and ten were excluded due to lack of randomization or different outcomes. A pool of 261 patients was randomly assigned to Pre-SA or No-SA. Meta-analysis of IGF1 normalization showed a significant difference in favor of Pre-SA (RR 2.47; 95% CI 1.66, 3.77). Adding a GH nadir on OGTT ≤1 μg/L, we found a RR of 2.15 (95% CI 1.39, 3.33). Quality of evidence for no need of adjuvant postoperative treatment was moderate, but for improving quality of life was very low and for mortality was absent.

CONCLUSION

Pre-SA increases the chance of biochemical control of acromegaly 3 months after TSS in patients harboring GH-secreting pituitary macroadenomas.

Preoperative somatostatin analogs treatment in acromegalic patients with macroadenomas. A meta-analysis

BACKGROUND

Several studies have investigated the biochemical remission rate of presurgical somatostatin analogs treatment on acromegaly, but the remission criteria were diversed and the results were contradicting.

OBJECTIVE

Aim of this paper is to provide enhanced evidence for the effectiveness of preoperative SSA treatment to improve on surgical results of macroadenomas in acromegaly.

DATA SOURCE

Literature is cited from the PubMed, Embase and Cochrane Library, dating from December, 1985 to August, 2013.

STUDY ELIGIBILITY CRITERIA

Eligibility criteria included patients with acromegaly caused by GH-secreting pituitary macroadenomas, patients pretreated with somatostatin analogs versus direct surgery and a stricter remission criteria defined as the GH nadir<1μg/l during an oral glucose tolerance test (OGTT) and the age- and sex- adjusted IGF-1 concentration was normal. Primary end points included Short term and long term postoperative biochemical remission.

STUDY APPRAISAL AND SYNTHESIS METHODS

A total of 1421 publications were found by the electronic search. After full-text review, 8 were included in our study. 7 of them focus on the postoperative remission in short term; 3 of them focus on the outcomes in long term. For the analysis of the postoperative biochemical remission, a random effect model was used to account for differences.

RESULTS

The meta analysis shows that patients in the SSA pretreatment groups have had a more significantly cure rate than those in the direct surgery groups (RR=1.72, 95%CI: 1.14-2.60, P=0.009) with a short term follow-up. Subgroup analysis proves benefit from lanreotide pretreated groups (RR=2.27, 95%CI: 1.34-3.84, P=0.002) but not octreotide pretreated groups (RR=1.51, 95%CI: 0.82-2.75, P=0.183). No significant differences appeared between the two groups (RR=1.03, 95%CI: 0.86-1.24, P=0.751) with a long term follow-up.

LIMITATIONS

2 Retrospective trial was included and most of the trials included was designed as single-center study.

CONCLUSIONS

Based on the analysis of this paper, the preoperative SSA treatment was beneficial in the group with short-term follow-up, while it was not advantageous in the group with long-term follow-up. For the limitations in this study, to drawn more solid conclusions, further large, randomized, multi-center, and long-term follow-up trials were required.

Aggressive pituitary tumors

Pituitary adenomas are common intracranial tumors that are mainly considered as benign. Rarely, these tumors can exhibit an aggressive behavior, characterized by gross invasion of the surrounding tissues, resistance to conventional treatment leading to early and frequent recurrences. Even more rarely, pituitary tumors can give rise to cerebrospinal or systemic metastases qualifying as pituitary carcinomas according to the latest WHO definition. In the same classification, a subset of tumors with relatively distinct histopathological features was identified and defined as atypical adenomas designated to follow a more aggressive clinical course. This classification, although clinically useful, does not provide an accurate correlation between histopathological findings and the clinical behavior of these tumors, neither is it adequate to convey the precise features of 'aggressive' tumors. Thus, 'aggressive' pituitary adenomas need to be properly defined with clinical, radiological, histological and molecular markers in order to identify patients at increased risk of early recurrence or subsequent tumor progression. At present, no single marker or classification system of pituitary tumor aggressiveness exists, and clinically useful information in the literature is insufficient to guide diagnostic and therapeutic decisions. Treatment of patients with aggressive pituitary tumors is challenging since conventional treatments often fail, necessitating multiple surgical procedures with additional radiotherapy. Although traditional chemotherapy applied in other neuroendocrine tumors has not been shown to be efficacious, newer agents, particularly temozolomide, have shown promising results and are currently used despite the lack of data from a randomized prospective trial. Molecular targeted therapies such as mTOR and epidermal growth factor inhibitors have also been applied and might prove to be useful in the management of these patients. In the present review, we provide information regarding the epidemiology and clinical, histopathological and molecular features of aggressive pituitary tumors using recent employed definitions. In addition, we review currently employed therapeutic means providing a therapeutic algorithm and highlight the need to identify more specific disease-related and prognostic markers and the necessity for central registration of these tumors.

Should all patients with acromegaly receive somatostatin analogue therapy before surgery and, if so, for how long?

Current guidelines do not recommend the routine use of somatostatin analogue pretreatment prior to surgery in patients with growth hormone-secreting pituitary tumours. In theory, presurgical use of somatostatin analogues should improve metabolic control and reduce soft tissue swelling, leading to improved anaesthetic outcomes. Shrinkage of tumours prior to surgery might also improve surgical remission rates. Hence, this article addresses the question: Should all patients with acromegaly receive a somatostatin analogue prior to surgery? Clinical trials published before December 2013 were reviewed, although literature in this area remains relatively deficient. We conclude: (i) On the basis of limited data available, somatostatin analogue pretreatment does not improve anaesthetic or immediate postoperative outcomes (i.e. hospital stay, rates of surgical complications and postoperative pituitary dysfunction). (ii) Somatostatin analogues should be considered in all patients with growth hormone-secreting macroadenomas, including invasive macroadenomas, when the overall surgical remission rate for macroadenomas at the treating centre is below 50%. Four recent RCTs have demonstrated increased rates of surgical remission using such an approach. (iii) When deemed appropriate, patients should be treated with somatostatin analogues for at least 3 months before surgery; there is currently no evidence that treatment beyond 6 months provides any additional benefit. Patients with minimally invasive macroadenomas are those most likely to benefit in terms of improved surgical remission.

Preoperative octreotide treatment of acromegaly: long-term results of a randomised controlled trial

OBJECTIVE

Randomised studies have demonstrated a beneficial effect of pre-surgical treatment with somatostatin analogues (SSA) in acromegaly when evaluated early postoperatively. The objective of this study was to evaluate the long-term surgical cure rates.

METHODS

Newly diagnosed patients were randomised to direct surgery (n=30) or 6-month pretreatment with octreotide LAR (n=32). The patients were evaluated 1 and 5 years postoperatively. Cure was defined as normal IGF1 levels and by normal IGF1 level combined with nadir GH <2 mU/l in an oral glucose tolerance test, all without additional post-operative treatment. A meta-analysis using the other published randomised study with long-term analyses on preoperative SSA treatment was performed.

RESULTS

The proportion of patients receiving post-operative acromegaly treatment was equal in the two groups. When using the combined criteria for cure, 10/26 (38%) macroadenomas were cured in the pretreatment group compared with 6/25 (24%) in the direct surgery group 1 year postoperatively (P=0.27), and 9/22 (41%) vs 6/22 (27%) macroadenomas, respectively, 5 years postoperatively (P=0.34). In the meta-analysis, 16/45 (36%) macroadenomas were cured using combined criteria in the pretreatment group vs 8/45 (18%) in the direct surgery group after 6-12 months (P=0.06), and 15/41 (37%) vs 8/42 (19%), respectively, in the long-term (P=0.08).

CONCLUSION

This study does not prove a beneficial effect of SSA pre-surgical treatment, but in the meta-analysis a trend towards significance can be claimed. A potential favourable, clinically relevant response cannot be excluded.

Management of endocrine disease: GH excess: diagnosis and medical therapy

Acromegaly is predominantly caused by a pituitary adenoma, which secretes an excess of GH resulting in increased IGF1 levels. Most of the GH assays used currently measure only the levels of the 22 kDa form of GH. In theory, the diagnostic sensitivity may be lower compared with the previous assays, which have used polyclonal antibodies. Many GH-secreting adenomas are plurihormonal and may co-secrete prolactin, TSH and α-subunit. Hyperprolactinaemia is found in 30-40% of patients with acromegaly, and hyperprolactinaemia may occasionally be diagnosed before acromegaly is apparent. Although trans-sphenoidal surgery of a GH-secreting adenoma remains the first treatment at most centres, the role of somatostatin analogues, octreotide long-acting repeatable and lanreotide Autogel as primary therapy is still the subject of some debate. Although the normalisation of GH and IGF1 levels is the main objective in all patients with acromegaly, GH and IGF1 levels may be discordant, especially during somatostatin analogue therapy. This discordance usually takes the form of high GH levels and an IGF1 level towards the upper limit of the normal range. Pasireotide, a new somatostatin analogue, may be more efficacious in some patients, but the drug has not yet been registered for acromegaly. Papers published on pasireotide have reported an increased risk of diabetes mellitus due to a reduction in insulin levels. Pegvisomant, the GH receptor antagonist, is indicated - alone or in combination with a somatostatin analogue - in most patients who fail to enter remission on a somatostatin analogue. Dopamine-D2-agonists may be effective as monotherapy in a few patients, but it may prove necessary to apply combination therapy involving a somatostatin analogue and/or pegvisomant.

The place of medical treatment of acromegaly: current status and perspectives

INTRODUCTION

Acromegaly is characterized by elevated growth hormone (GH) and insulin-like growth factor-I (IGF-I) levels and by progressive somatic disfigurement and systemic manifestations, which lead to a mortality rate higher than the general population. Therefore, diagnosis and properly treatment should be performed as soon as possible.

AREAS COVERED

This article focuses on the state of the art of acromegaly medical treatment. Somatostatin analogs, dopamine agonists and GH receptor antagonist were reviewed. Somatostatin analogs, the first-choice pharmacotherapy, can be used as primary or pre-operative treatment or as secondary therapy after failed surgery. Dopamine agonists have been used in patients with slightly elevated hormone levels and/or mixed GH/prolactin adenomas. Pegvisomant is indicated for resistant to somatostatin analogs/dopamine agonists. Combined treatment is also an option for resistant cases. Other non-conventional therapies and perspectives of treatment were also been discussed.

EXPERT OPINION

The control of disease activity in acromegaly is of paramount importance. Medical treatment is an important option for cases in which surgery was unsuccessful or not indicated. Despite the achievements in medical treatment, somatotropic tumor aggressiveness and/or resistance to the drugs currently available remain a concern. Therefore, novel therapy targets based on molecular pathogenesis of GH-secreting tumors are currently in development, aiming at fulfilling this important gap.