Acromegaly: an endocrine society clinical practice guideline

OBJECTIVE

The aim was to formulate clinical practice guidelines for acromegaly.

PARTICIPANTS

The Task Force included a chair selected by the Endocrine Society Clinical Guidelines Subcommittee (CGS), five experts in the field, and a methodologist. The authors received no corporate funding or remuneration. This guideline is cosponsored by the European Society of Endocrinology.

EVIDENCE

This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system to describe both the strength of recommendations and the quality of evidence. The Task Force reviewed primary evidence and commissioned two additional systematic reviews.

CONSENSUS PROCESS

One group meeting, several conference calls, and e-mail communications enabled consensus. Committees and members of the Endocrine Society and the European Society of Endocrinology reviewed drafts of the guidelines.

CONCLUSIONS

Using an evidence-based approach, this acromegaly guideline addresses important clinical issues regarding the evaluation and management of acromegaly, including the appropriate biochemical assessment, a therapeutic algorithm, including use of medical monotherapy or combination therapy, and management during pregnancy.

Guidelines for acromegaly management: an update

OBJECTIVE

The Acromegaly Consensus Group reconvened in November 2007 to update guidelines for acromegaly management.

PARTICIPANTS

The meeting participants comprised 68 pituitary specialists, including neurosurgeons and endocrinologists with extensive experience treating patients with acromegaly. EVIDENCE/CONSENSUS PROCESS: Goals of treatment and the appropriate imaging and biochemical and clinical monitoring of patients with acromegaly were enunciated, based on the available published evidence.

CONCLUSIONS

The group developed a consensus on the approach to managing acromegaly including appropriate roles for neurosurgery, medical therapy, and radiation therapy in the management of these patients.

Determinants of clinical outcome and survival in acromegaly

OBJECTIVE

The extent to which treatment modifies the excess in morbidity and mortality in acromegaly remains uncertain. This study investigates the determinants of final outcome following therapy for acromegaly.

DESIGN

A retrospective analysis of patients treated at the Departments of Endocrinology and Neurosurgery, Auckland Hospital, New Zealand.

PATIENTS

One hundred and fifty-one patients (63 females and 88 males) with acromegaly or gigantism treated between the years 1964 and 1989. The mean duration of follow-up was 12 years (median 11 years).

MEASUREMENTS

Patients had their age, estimated duration of symptoms preceding diagnosis, serum GH at diagnosis, presence of diabetes mellitus, cardiovascular disease, hypertension and/or osteoarthritis at diagnosis and the last known serum GH documented. The final outcome at the time of study was graded under three classes: dead (n = 32), those with major complications (n = 47) and those with minor/no complications (n = 67).

RESULTS

The mean age at diagnosis of acromegaly was 41 years and the average estimated duration of symptoms prior to diagnosis was 7 years, with older patients showing longer duration of symptoms preceding diagnosis (P = 0.0002). Final outcome (dead, alive with major complications, alive and well) was significantly worse in those with older age at diagnosis (P = 0.008), longer duration of symptoms before diagnosis (P = 0.03) and higher GH at last follow-up (P = 0.0001). In multivariate analysis, survival was significantly influenced by the last known GH (P = 0.0001), presence of hypertension (P = 0.02) or cardiac disease (P = 0.03) at diagnosis, and duration of symptoms prior to diagnosis (P = 0.04). Survival in the acromegalic group, irrespective of treatment, was reduced by an average of 10 years compared with the non-acromegalic population.

CONCLUSIONS

Acromegaly has a significant adverse effect on well-being and survival. The predominant determinant of outcome is the final serum GH level following treatment.

The outcome of surgery in 668 patients with acromegaly using current criteria of biochemical 'cure'

BACKGROUND AND AIM

The aim of this study was to illustrate the present role of transsphenoidal surgery as primary therapy in GH-secreting adenomas, and to compare the results concerning control of disease with previous series using older criteria of cure.

METHOD

We report on a consecutive series of 688 acromegalic patients treated over a time period of 19 years. Biochemical cure was defined as normalisation of basal GH level, suppression of GH levels to below 1 ng/ml during an oral glucose load and normalisation of IGF-I levels. Of the 506 patients undergoing primary transsphenoidal surgery, a total of 57.3% postoperatively fulfilled the criteria used.

RESULTS

The rate of biochemical 'cure' correlated with the magnitude of the initial GH levels, the tumour size and invasion. The overall complication rate was below 2%. Mortality in this series was 0.1% (1 of 688). During a follow-up period of 10.7 years only two recurrences (0.4%) occurred. However, in the patients treated by transcranial surgery and by repeat surgery the cure rate was found to be relatively low (5.2 and 21.3% respectively).

CONCLUSIONS

These data suggest that surgery remains with very few exceptions the primary treatment of acromegaly for (i) a high cure rate, (ii) low morbidity, (iii) low recurrence rate and (iv) immediate decline of GH. Based on current criteria of cure, recurrences are uncommon. However, cure by surgery alone is improbable in patients harbouring extended, invasive tumours with high secretory activity, in whom further adjuvant treatment is mandatory.

Expert consensus document: A consensus on the medical treatment of acromegaly

In March 2013, the Acromegaly Consensus Group met to revise and update guidelines for the medical treatment of acromegaly. The meeting comprised experts skilled in the medical management of acromegaly. The group considered treatment goals covering biochemical, clinical and tumour volume outcomes, and the place in guidelines of somatostatin receptor ligands, growth hormone receptor antagonists and dopamine agonists, and alternative modalities for treatment including combination therapy and novel treatments. This document represents the conclusions of the workshop consensus.

Epidemiology, clinical characteristics, outcome, morbidity and mortality in acromegaly based on the Spanish Acromegaly Registry (Registro Espanol de Acromegalia, REA)

OBJECTIVE

To undertake a multicentre epidemiological study reflecting acromegaly in Spain.

DESIGN

Voluntary reporting of data on patients with acromegaly to an online database, by the managing physician.

METHODS

Data on demographics, diagnosis, estimated date of initial symptoms and diagnosis, pituitary imaging, visual fields, GH and IGF-I concentrations (requested locally), medical, radiotherapy and neurosurgical treatments, morbidity and mortality were collected.

RESULTS

Data were included for 1219 patients (60.8% women) with a mean age at diagnosis of 45 years (s.d. 14 years). Reporting was maximal in 1997 (2.1 cases per million inhabitants (c.p.m.) per year); prevalence was globally 36 c.p.m., but varied between 15.7 and 75.8 c.p.m. in different regions. Of 1196 pituitary tumours, most were macroadenomas (73%); 81% of these patients underwent surgery, 45% received radiotherapy and 65% were given medical treatment (somatostatin analogues in 68.3% and dopamine agonists in 31.4%). Cures (GH values (basal or after an oral glucose tolerance test) <2 ng/ml, normal IGF-I, or both) were observed in 40.3% after surgery and 28.2% after radiotherapy. Hypertension (39.1%), diabetes mellitus (37.6%), hypopituitarism (25.7%), goitre (22.4%), carpal tunnel syndrome (18.7%) and sleep apnoea (13.2%) were reported as most frequent morbidities; 6.8% of the patients had cancer (breast in 3.1% of the women and colon in 1.2% of the cohort). Fifty-six patients died at a mean age of 60 years (s.d. 14 years), most commonly of a cardiovascular cause (39.4%); mortality was greater in patients given radiotherapy (hazard ratio 2.29; 95% confidence interval 1.03 to 5.08; P=0.026), and in those in whom GH and IGF-I concentrations were never normal (P<0.001).

CONCLUSIONS

This acromegaly registry offers a realistic overview of the epidemiological characteristics, treatment outcome and morbidity of acromegaly in Spain. As active disease and treatment with radiotherapy are associated with an increase in mortality, efforts to control the disease early are desirable.

Endoscopic transsphenoidal surgery for acromegaly: remission using modern criteria, complications, and predictors of outcome

CONTEXT

Despite the growing application of endoscopic transsphenoidal surgery (ETSS), outcomes for GH adenomas are not clearly defined.

OBJECTIVE

We reviewed our experience with ETSS with specific interest in remission rates using the 2010 consensus criteria, predictors of remission, and associated complications.

DESIGN AND SETTING

This was a retrospective single institution study. PATIENTS, INTERVENTIONS, AND OUTCOME MEASURES: Sixty acromegalic patients who underwent ETSS were identified. Remission was defined as a normal IGF-I and either a suppressed GH less than 0.4 ng/ml during an oral glucose tolerance test or a random GH less than 1.0 ng/ml.

RESULTS

Remission was achieved in all 14 microadenomas and 28 of 46 macroadenomas (61%). Tumor size, age, gender, and history of prior surgery were not predictive on multivariant analysis. In hospital postoperative morning GH levels less than 2.5 ng/ml provided the best prediction of remission (P < 0.001). Preoperative variables predictive of remission included Knosp score (P = 0.017), IGF-I (P = 0.030), and GH (P = 0.042) levels. New endocrinopathy consisted of diabetes insipidus in 5%, adrenal insufficiency in 5.4%, and new hypogonadism in 29% of men and 17% of women. However, 41% of hypogonadal men had normal postoperative testosterone levels and 83% of amenorrheic women regained menses. The most common complaints after surgery were sinonasal (36 of 60, 60%) resolving in all but two.

CONCLUSIONS

ETSS for GH adenomas is associated with high rates of remission and a low incidence of new endocrinopathy. Despite the panoramic views offered by the endoscope, invasive tumors continue to have lower rates of remission.

Somatotroph hyperplasia. Successful treatment of acromegaly by removal of a pancreatic islet tumor secreting a growth hormone-releasing factor

A 21-yr-old woman with Turner's syndrome presented with signs and symptoms of acromegaly. The serum growth hormone (GH) (95+/-9.4 ng/ml; mean+/-SEM) and somatomedin C (11 U/ml) levels were elevated, and an increase in GH levels after glucose instead of normal suppression, increase after thyrotropin-releasing hormone (TRH) administration instead of no change, and decrease after dopamine administration instead of stimulation were observed. The pituitary fossa volume was greater than normal (1,440 mm(3)) and the presence of a pituitary tumor was assumed. After tissue removal at transsphenoidal surgery, histological study revealed somatotroph hyperplasia rather than a discrete adenoma. Postoperatively, she remained clinically acromegalic and continued to show increased GH and somatomedin levels. A search was made for ectopic source of a growth hormone-releasing factor (GRF). Computer tomographic scan revealed a 5-cm Diam tumor in the tail of the pancreas. Following removal of this tumor, serum GH fell from 70 to 3 ng/ml over 2 h, and remained low for the subsequent 5 mo. Serum somatomedin C levels fell from 7.2 to normal by 6 wk postoperatively. There were no longer paradoxical GH responses to glucose, TRH, and dopamine. Both the medium that held the tumor cells at surgery and extracts of the tumor contained a peptide with GRF activity. The GRF contained in the tumor extract coeluted on Sephadex G-50 chromatography with rat hypothalamic GH-releasing activity. Stimulation of GH from rat somatotrophs in vitro was achieved at the nanomolar range, using the tumor extract. The patient's course demonstrates the importance of careful interpretation of pituitary histology. Elevated serum GH and somatomedin C levels in a patient with an enlarged sella turcica and the characteristic responses seen in acromegaly to TRH, dopamine, and glucose do not occur exclusively in patients with discrete pituitary tumors and acromegaly. This condition can also occur with somatotroph hyperplasia and then revert to normal after removal of the GRF source. Thus, in patients with acromegaly a consideration of ectopic GRF secretion should be made, and therefore, careful pituitary histology is mandatory. Consideration for chest and abdominal computer tomographic scans before pituitary surgery, in spite of their low yield, may be justified.

Long-term outcome and mortality after transsphenoidal adenomectomy for acromegaly

OBJECTIVE

Acromegaly has long been associated with increased mortality but few long-term follow-up data are available in patients treated for this disease. We therefore studied a group of 103 patients who underwent transsphenoidal adenomectomy for acromegaly between 1970 and 1999 and were followed for one to 30 years.

DESIGN AND PATIENTS

A retrospective chart review was performed on 103 patients living in the province of Quebec, Canada. Mortality data were obtained by hospital charts, contact with the patient's family or death certificates. Stringent biochemical criteria were used to define remission (random GH < 2.5 microg/l, or GH nadir after an oral glucose load is < 1 microg/l and IGF-I within the normal range) and patient survival in the group in remission and the group with persistent disease were compared to survival of the population of Quebec, Canada, using the probabilities of the Poisson distribution.

RESULTS

There were four deaths in the perioperative period, one of which was directly related to surgery. Initial remission was obtained in 82% of microadenomas, 60% of macroadenomas and 24% of invasive adenomas. The long-term (> or = 10 years) remission rate for surgery alone was 52%. A second transsphenoidal surgery, radiation therapy and/or octreotide were used in a subset of patients with persistent disease. Long-term remission was obtained in 63% of patients. Five (mean age, 64 years) of the 57 patients in remission died; this rate did not differ significantly from the mortality rate expected in the general population (P = 0.18). Thirteen (mean age, 59.8 years) of the 34 patients with persistent disease died; this rate was significantly higher than that expected in the general population (P = 0.008).

CONCLUSIONS

Our observations confirm that uncontrolled acromegaly increases mortality compared to the general population and that mortality rates similar to the general population are restored once remission is induced.

A decade of pituitary microsurgery. The Herbert Olivecrona lecture

The author reviews his experience with surgical treatment of 1000 pituitary tumors, the majority of which were endocrine-active. The criteria of grading, the microsurgical technique used, and the postoperative results are presented. The mortality rate was 0.2% overall, with no deaths in the group of 774 patients with endocrine-active adenomas.

Outcome of transphenoidal surgery for acromegaly and its relationship to surgical experience

BACKGROUND

A number of surgical series have been reported on the treatment of acromegaly and their results vary widely. The acceptable definition of remission has changed in recent years and it is known, though in a small series, that growth hormone levels of > 5 mU/l are still associated with an increased mortality from the condition. We have analysed data at this centre and examined the outcome of transphenoidal surgery for acromegaly, compared our results with recently published series from other centres and also assessed factors which might effect outcome including whether there is any demonstrable effect of the experience of the surgeon on outcome.

PATIENTS AND METHODS

We have analysed data from all of our 139 patients in whom follow up data are available who have undergone initial transphenoidal surgery for acromegaly by one surgeon at this centre, between 1974 and 1995. Follow up was for a median of 5 years (range 1 month to 17 years).

RESULTS

67% of patients achieved the criterion for remission (mean GH < 5 mU/l). Success was related to tumour size and preoperative growth hormone values. Thus 91% of patients with microadenomas were in remission postoperatively compared to 46% of patients with macroadenomas. Analysis of the results according to the year of operation showed an improvement in success rates with time. More than 15 years ago, the success rate according to the growth hormone criteria set was 48% and the failure rate 52%. In contrast in the last 5 years analysed, the overall success rate was 74% with a failure rate of 26% (P < 0.04). The success rate for microadenomas was 50% initially, then remained 100%. The case mix was analysed and no change was found. We have also demonstrated an improvement in pituitary function (including normalization of preoperative elevated prolactin) with time so that pre 1981 16% of patients' pituitary function improved perioperatively but 10 years later this figure had risen to 34% (P < 0.03). There was no change over time in the development of pituitary hypofunction, complication rate or recurrence rate.

CONCLUSION

Surgical treatment is a safe and effective treatment for acromegaly and remains the first choice of treatment for most acromegalic patients. The results of this centre compare favourably with series from other centres. We have demonstrated improved results, both in terms of post operative growth hormone values and pituitary function tests with time and increasing neurosurgical experience. We conclude that outcome for the surgical treatment for acromegaly is best achieved with one surgeon specialising in pituitary surgery. Improved operative outcome thus achieved has major cost implications and avoids the necessity for consideration of postoperative radiotherapy and the use of expensive growth hormone suppressing drugs in the postoperative period.

Consensus statement: medical management of acromegaly

In November 2003, the Pituitary Society and the European Neuroendocrine Association sponsored a consensus workshop in Seville to address challenging issues in the medical management of acromegaly. Participants comprised 70 endocrinologists and neurosurgeons with international expertise in managing patients with acromegaly. All participants participated in the workshop proceedings, and the final document written by the scientific committee reflects the consensus opinion of the interactive deliberations. The meeting was supported by an unrestricted educational grant from Ipsen. No pharmaceutical representatives participated in the program planning or in the scientific deliberations.

Transsphenoidal microsurgery for growth hormone-secreting pituitary adenomas: initial outcome and long-term results

Treatment of acromegaly has long been recognized as necessary to relieve symptoms, halt progression of deformities, and decompress the sella turcica. More recently, treatment strategies have focused on decreasing GH levels to a point at which mortality rates normalize, thereby redefining previous concepts of a cure. No surgical series to date has investigated the long-term effect of treatment on mortality rates. We retrospectively reviewed 254 consecutive patients with acromegaly who underwent transsphenoidal microsurgery of GH-secreting adenomas between 1974-1992. Seventy-six percent of these patients had basal GH levels <5 ng/mL within 30 days of surgery, and 24% had persistent disease. Multivariate analysis revealed that higher stage, grade, and preoperative GH levels were all predictive of persistence (P < 0.01). Long-term follow-up was obtained on 129 of the patients in initial remission. Of these, 9 (7%) had disease recurrence and 120 remained in remission. The incidence of major postoperative complications was 8% (2% permanent diabetes insipidus, 2% cerebrospinal fluid leaks requiring surgery, 2% meningitis, and 2% hypopituitarism), with no mortality. In contrast to the 2.4- to 4.8-fold increased mortality among untreated acromegalics, the mortality rate among patients with posttherapy GH levels <5 ng/mL was equivalent to that of age- and sex-matched controls. Aggressive therapy to normalize GH levels should therefore be instituted at diagnosis.

Endoscopic vs microsurgical transsphenoidal surgery for acromegaly: outcomes in a concurrent series of patients using modern criteria for remission

CONTEXT

It is unclear whether endoscopic transsphenoidal surgery (ETSS) or microsurgical transsphenoidal surgery (MTS) is a superior surgical approach for pituitary adenomas.

OBJECTIVE

The objective of the study was to compare the outcome of surgery with ETSS and MTS by experienced pituitary surgeons using criteria of remission using current consensus criteria for acromegaly.

DESIGN AND SETTING

This was a retrospective review of prospectively recorded outcomes. The study was conducted at a tertiary referral center. Patients, Interventions, and Outcome Measures: Remission was defined as a normal IGF-I level and either suppressed GH less than 0.4 ng/mL during an oral glucose tolerance test or random GH less than 1.0 ng/mL. The Youden indices were calculated to determine the optimal cutoffs for using immediate postoperative GH levels to predict the results of later testing for remission.

RESULTS

Preoperative demographics and tumor characteristics were not significantly different between patients undergoing ETSS (72 patients) or MTS (41 patients). Overall, postoperative remission was achieved in 20 of 23 microadenomas (87%) and 59 of 90 macroadenomas (66%). Remission rates and perioperative complications were not significantly different between ETSS and MTS groups, except for self-reported sinusitis and alterations in taste or smell, which were significantly higher in patients treated with ETSS. Preoperative variables predicting remission in multivariate analysis included GH less than 45 ng/mL [odds ratio (OR) 6.4, P = .010)] and Knosp score of 0-2 (OR 6.8, P < .001). Postoperative in-hospital GH less than 1.15 ng/mL provided the best predictor of remission (OR 7.7, P < .001; sensitivity of 73%, specificity of 85%) defined by follow-up testing.

CONCLUSIONS

Outcomes of transsphenoidal surgery for acromegaly by experienced pituitary surgeons do not differ between endoscopic and microscopic techniques. Regardless of the mode of resection, patients with high preoperative GH levels and Knosp scores are less likely to achieve remission. An immediate postoperative GH level of less than 1.15 ng/mL provides the best immediate predictor of remission, but long-term outcomes are indicated.

Conventional supervoltage irradiation is an effective treatment for acromegaly

Forty-seven acromegalic patients were treated with conventional supervoltage irradiation (4000-5000 rads) and were followed-up at 2, 5, and 10 yr after treatment. The mean fall in the GH concentrations 5 years after treatment was 77%, and GH was less than 10 ng/ml in 73% of the cases. In the majority, GH continued to fall over the 5- to 10-yr interval after treatment, so that by 10 yr, plasma GH was less than or equal to 10 ng/ml in 81% and less than or equal to 5 ng/ml in 69% of the patients. Also, the subjective (acral and facial changes) and the objective (metabolic) effects of GH excess all showed significant improvement with time, and the improvement roughly paralleled the fall in plasma GH concentrations. After therapy, no patient developed extrasellar extension, and headaches improved in the majority of patients. The prevalence of hypopituitarism, which was low before treatment, increased progressively throughout the follow-up period. Significant loss of vision was observed in only one patient, who received 5600 rads and had severe systemic sarcoidosis. The only other complication was temporal hair loss. Conventional super-voltage irradiation by 5-10 yr produces the same fall in plasma GH as all other forms of treatment for acromegaly, including transphenoidal microsurgery. The rate of fall in plasma GH after conventional irradiation is comparable to that of more aggressive forms of irradiation and is slower than that achieved by surgical methods but probably conventional irradiation has fewer serious side effects.

Stereotactic radiosurgery for recurrent surgically treated acromegaly: comparison with fractionated radiotherapy

OBJECT

The authors tested the assumption that gamma knife radiosurgery is more effective than fractionated radiotherapy for the treatment of patients with acromegaly who have undergone unsuccessful resective surgery. Untreated and uncured acromegaly causes illness and death. Acromegalic patients in whom growth hormone and, particularly, insulin-like growth factor I are not normalized must undergo further treatment.

METHODS

After unsuccessful operations, 16 patients suffering from recurrent and uncured acromegaly underwent stereotactic radiosurgery (25 Gy to the tumor margin, 50 Gy maximum), the outcome of which was compared with the result obtained in 50 patients who received fractionated radiotherapy (40 Gy). The cumulative distribution functions of the two groups (Kaplan-Meier estimate) differed significantly (p < 0.0001 in the log-rank test of Mantel). The mean time to simultaneous normalization of both parameters was 1.4 years in the group treated with the gamma knife and 7.1 years in the group treated with fractionated radiotherapy.

CONCLUSIONS

The authors suggest the use of stereotactic radiosurgery as the preferred treatment for recurrent acromegaly resulting from unsuccessfully resected tumors.

Prevalence, predictors and patterns of postoperative polyuria and hyponatraemia in the immediate course after transsphenoidal surgery for pituitary adenomas

OBJECTIVE

Disturbances of osmoregulation, leading to diabetes insipidus and hyponatraemia are well known complications after surgery in the sella region. This study was performed to examine the prevalence and predictors of polyuria and hyponatraemia after a complete and selective removal of pituitary adenomas was attempted via the transnasal-transsphenoidal approach.

DESIGN

1571 patients with pituitary adenomas (238 Cushing's disease, 405 acromegaly, 534 hormonally inactive adenomas, 358 prolactinoma, 23 Nelson's syndrome, and 13 thyrotropinoma) were daily examined within a 10-day postoperative inpatient observation period. Prevalence of patterns of polyuria (> 2500 ml) and oliguria/hyponatraemia (< 132 mmol/l) were surveyed as well as predictors of postoperative morbidity.

RESULTS

487 patients (31%) developed immediate postoperative hypotonic polyuria, 161 patients (10%) showed prolonged polyuria and 37 patients (2.4%) delayed hyponatraemia. A biphasic (polyuria-hyponatraemia) and triphasic (polyuria-hyponatraemia-polyuria) pattern was seen in 53 (3.4%) and 18 (1.1%) patients, respectively. Forty-one patients (2.6%) displayed immediate postoperative (day 1) hyponatraemia. Altogether, 8.4% of patients developed hyponatraemia at some time up to the 10th day postoperative, with symptomatic hyponatraemia in 32 patients (2.1%). Risk analysis showed that patients with Cushing's disease had a fourfold higher risk of polyuria than patients with acromegaly and a 2.8-fold higher risk for postoperative hyponatraemia. Younger age, male sex, and intrasellar expansion were associated with a higher risk of hypotonic polyuria, but this was not considered clinically relevant.

CONCLUSIONS

The analysis illustrates that disturbances in osmoregulation resulting in polyuria and pertubations of serum sodium concentration are of very high prevalence and need observation even after selective transsphenoidal surgery for pituitary adenomas, especially in patients with Cushing's disease.

Long-term endocrinological follow-up evaluation in 115 patients who underwent transsphenoidal surgery for acromegaly

OBJECT

The results of surgical therapy for acromegaly were assessed using carefully conducted endocrinological testing in 115 patients who underwent transsphenoidal surgery from 1981 to 1995.

METHODS

Ninety-nine of the 115 patients could be contacted for follow-up review; in 57 of the patients an endocrinological assessment was performed by the authors. Biochemical cure was strictly defined as a normalization of the insulin-like growth factor(IGF)-I level (obtained in 100 patients) and/or a basal or glucose-suppressed growth hormone (GH) level of 2 ng/ml or less. The mean length of follow up from transsphenoidal surgery to laboratory testing was 5.4 years with a maximum of 15.7 years. After transsphenoidal surgery alone, 61% of the patients achieved a biochemical remission; the remission rate was 88% for patients with microadenomas and 53% for those with macroadenomas. Tumor size and preoperative GH level tended to correlate negatively with outcome of surgery. Early postoperative GH level tended to correlate with long-term outcome; in cases in which the early postoperative GH level was lower than 3 ng/ml, the chance of long-term remission was 89%. Thirty-two patients received postoperative radiotherapy: in 10 (31%) of these patients the disease is currently in remission after surgery and radiotherapy only and in three others the disease is in remission with the addition of medical therapy. The overall complication rate was 6.9% with no cerebrospinal fluid leaks, meningitis, permanent diabetes insipidus, or new hypopituitarism. The overall recurrence rate was low at 5.4%.

CONCLUSIONS

This series shows, based on IFGF-I measurements and strict GH suppression criteria to define remission, that transsphenoidal surgery provides an excellent chance for long-term cure in patients with microadenomas. Surgery alone is successful in most patients with noninvasive macroadenomas; however, most patients with invasive macroadenomas will require adjunctive therapy. Recurrences are uncommon when biochemical remission is clearly documented postoperatively.

Outcome of gamma knife radiosurgery in 82 patients with acromegaly: correlation with initial hypersecretion

CONTEXT

Because surgical and medical therapies of acromegaly all have specific limitations, radiotherapy has been used as an adjunctive strategy. Stereotactic radiosurgery has not yet been widely evaluated.

OBJECTIVE

The objective was to perform an analysis of long-term hormonal effects and tolerance of gamma knife radiosurgery.

DESIGN

Eighty-two patients were prospectively studied over a decade, with a mean follow-up of 49.5 months.

SETTING

All patients were treated at the Department of Functional Neurosurgery of Marseille, France.

PATIENTS

The patients included 82 with active acromegaly, of whom 63 had previous transsphenoidal surgery.

INTERVENTION

Intervention included radiosurgery using the Leksell Gamma Unit B model.

MAIN OUTCOME MEASURES

Remission was diagnosed when mean GH levels were less than 2 ng/ml and IGF-I was normal for age off somatostatin agonists (at least 3 months).

RESULTS

Seventeen percent of the patients were in remission without any treatment. Twenty-three percent previously uncontrolled on somatostatin agonists fulfilled the same criteria after gamma knife while maintained on medical treatment. Initial GH and IGF-I levels off somatostatin agonists were significantly higher in uncured than in remission group (P = 0.01 and 0.047, respectively). Withdrawal of somatostatin agonists at the time of radiosurgery had no incidence on the outcome. No significant difference was found in success rate whether patients had previously been treated or not. Long-term side effects included complete (n = 2) or partial (n = 12) hypopituitarism diagnosed 1-7 yr after gamma knife.

CONCLUSIONS

Gamma knife radiosurgery may represent a therapeutic approach in patients with moderate initial or residual GH hypersecretion.

Adenoma granulation pattern correlates with clinical variables and effect of somatostatin analogue treatment in a large series of patients with acromegaly

CONTEXT

Somatotroph adenomas have been classified into densely granulated (DG) and sparsely granulated (SG) tumours with a transitional, intermediate group. Gsp oncogenes are activating mutations in the Gsα subunit gene, found in approximately 40% of somatotroph adenomas.

OBJECTIVES

To explore granulation pattern and presence of gsp oncogene in acromegaly with correlations to clinical and biochemical variables and to the effect of treatment with somatostatin analogues (SA), as well as to describe granulation pattern in adenomas with and without SA pretreatment.

DESIGN/SETTINGS/PATIENTS

Seventy-eight patients with active acromegaly were included. Long-term SA efficacy was evaluated in 29 patients treated preoperatively and in ten treated postoperatively. Granulation pattern was examined, as were immunohistochemical analyses for E-cadherin and SSTR2a. Protein levels of E-cadherin and SSTR2a were measured (Western blot). Gsp mutation analysis was available for 74 adenomas.

RESULTS

DG adenomas and the transitional group had higher serum levels of IGF-1 per tumour volume than SG (P = 0·009; P = 0·005). Acute and long-term SA responses were lower in SG (P = 0·001; P = 0·043). No correlation between gsp mutation and granulation was found, and no difference in granulation pattern according to preoperative SA treatment was demonstrated. A significant correlation between granulation and E-cadherin was found, where SG had lowest immunohistochemical expression, substantiated by protein levels, and a highly significant gradient was observed from DG, through the transitional group, to SG.

CONCLUSIONS

Densely granulated adenomas were highly responsive to somatostatin analogues in contrast to SG adenomas. The transitional group behaved clinically more like DG adenomas. However, based on E-cadherin, a marker of dedifferentiation, the transitional group seemed to be a true intermediate.

Determinants of survival in treated acromegaly in a single center: predictive value of serial insulin-like growth factor I measurements

We evaluated survival after optimal treatment for acromegaly and assessed the predictive effects of different remission criteria for survival in 164 consecutive acromegalic patients, treated by transsphenoidal surgery and adjuvant therapy between 1977 and 2002. The goal of treatment was a mean GH less than 5 mU/liter, a normal glucose-suppressed GH, and a normal IGF-I for age in all patients. Surgery initially cured 108 patients (66%). Adjuvant therapy for persistent disease was given to 49 patients. At the end of follow-up (mean, 12.3 yr), remission rates for surgery and multimodality treatment were 54% and 90%, respectively. In 2033 person-years of follow-up, 28 of 164 patients died, resulting in an observed:expected mortality ratio of 1.3 (confidence interval, 0.87-1.87). Significant predictors for survival were the duration of disease and the postoperative glucose-suppressed GH. The effects of these predictors became less significant with increasing follow-up duration. A time-dependent effect on survival was observed for serial IGF-I concentrations, but not for serial GH concentrations. Of the three remission criteria, IGF-I was the only one to be significantly associated with survival in this study, with a relative risk of 4.78 for an elevated as opposed to a normal IGF-I concentration.

Preoperative octreotide treatment in newly diagnosed acromegalic patients with macroadenomas increases cure short-term postoperative rates: a prospective, randomized trial

CONTEXT

Surgery is the primary treatment of acromegaly. However, it often fails to cure the patient. New strategies that improve surgical outcome are needed.

OBJECTIVE

Our objective was to investigate whether 6-month preoperative treatment with octreotide improves the surgical outcome in newly diagnosed acromegalic patients.

PATIENTS

During a 5-yr period (1999-2004), all newly diagnosed acromegalic patients between 18 and 80 yr of age in Norway were screened and invited to participate in the study. A total of 62 patients was included in the Preoperative Octreotide Treatment of Acromegaly study.

RESEARCH DESIGN AND METHODS

After a baseline evaluation, patients were randomized directly to transsphenoidal surgery (n = 30) or pretreatment with octreotide (n = 32) 20 mg im every 28th day for 6 months before transsphenoidal surgery. Cure was evaluated 3 months postoperatively primarily by IGF-I levels.

RESULTS

According to the IGF-I criteria, 14 of 31 (45%) pretreated patients vs. seven of 30 (23%) patients with direct surgery were cured by surgery (P = 0.11). In patients with microadenomas (< or = 10 mm), one of five (20%) pretreated vs. three of five (60%) with direct surgery were cured (P = 0.52). In patients with macroadenomas, 13 of 26 (50%) pretreated vs. four of 25 (16%) with direct surgery were cured (P = 0.017).

CONCLUSIONS

Six-month preoperative octreotide treatment might improve surgical cure rate in newly diagnosed acromegalic patients with macroadenomas. These results have to be confirmed in future studies.

Gamma-knife radiosurgery in acromegaly: a 4-year follow-up study

Stereotactic radiosurgery by gamma-knife (GK) is an attractive therapeutic option after failure of microsurgical removal in patients with pituitary adenoma. In these tumors or remnants of them, it aims to obtain the arrest of cell proliferation and hormone hypersecretion using a single precise high dose of ionizing radiation, sparing surrounding structures. The long-term efficacy and toxicity of GK in acromegaly are only partially known. Thirty acromegalic patients (14 women and 16 men) entered a prospective study of GK treatment. Most were surgical failures, whereas in 3 GK was the primary treatment. Imaging of the adenoma and target coordinates identification were obtained by high resolution magnetic resonance imaging. All patients were treated with multiple isocenters (mean, 8; range, 3-11). The 50% isodose was used in 27 patients (90%). The mean margin dose was 20 Gy (range, 15-35), and the dose to the visual pathways was always less than 8 Gy. After a median follow-up of 46 months (range, 9-96), IGF-I fell from 805 micro g/liter (median; interquartile range, 640-994) to 460 micro g/liter (interquartile range, 217-654; P = 0.0002), and normal age-matched IGF-I levels were reached in 7 patients (23%). Mean GH levels decreased from 10 micro g/liter (interquartile range, 6.4-15) to 2.9 micro g/liter (interquartile range, 2-5.3; P < 0.0001), reaching levels below 2.5 micro g/liter in 11 (37%). The rate of persistently pathological hormonal levels was still 70% at 5 yr by Kaplan-Meier analysis. The median volume was 1.43 ml (range, 0.20-3.7). Tumor shrinkage (at least 25% of basal volume) occurred after 24 months (range, 12-36) in 11 of 19 patients (58% of assessable patients). The rate of shrinkage was 79% at 4 yr. In no case was further growth observed. Only 1 patient complained of side-effects (severe headache and nausea immediately after the procedure, with full recovery in a few days with steroid therapy). Anterior pituitary failures were observed in 2 patients, who already had partial hypopituitarism, after 2 and 6 yr, respectively. No patient developed visual deficits. GK is a valid adjunctive tool in the management of acromegaly that controls GH/IGF-I hypersecretion and tumor growth, with shrinkage of adenoma and no recurrence of the disease in the considered observation period and with low acute and chronic toxicity.

Partial surgical removal of growth hormone-secreting pituitary tumors enhances the response to somatostatin analogs in acromegaly

CONTEXT

Surgery is a cornerstone in the treatment of acromegaly, but its efficacy in large, invasive tumors is scant.

OBJECTIVE

The objective of this study was to investigate whether partial surgical removal of GH-secreting pituitary tumors enhances the response rate to somatostatin analogs (SSA; sc octreotide, slow-release octreotide, and lanreotide).

DESIGN

This was a multicenter, open, retrospective study.

SETTING

The study was performed at university hospitals.

SUBJECTS AND METHODS

Eighty-six patients (42 women and 44 men; age, 42 +/- 14 yr) with acromegaly were studied.

INTERVENTIONS

Patients underwent two courses of octreotide, lanreotide, or slow-release octreotide treatments before and after surgery of at least 6 months.

MAIN OUTCOME MEASURE

The main outcome measure was normal IGF-I levels for age.

RESULTS

Presurgical SSA treatment significantly decreased GH and IGF-I levels in all patients. GH levels were less than 2.5 microg/liter in 12 patients (14%); IGF-I levels normalized in nine (10%). After surgery, GH and IGF-I levels further decreased in all patients; tumor removal was greater than 75% in 50 (58%), 50.1-75% in 21 (24%), 25.1-50% in 10 (12%), and less than 25% in five patients (6%). Preoperatively, pituitary function was impaired in 12 patients (14%). Postsurgical SSA treatment lowered GH levels to less than 2.5 microg/liter in 49 (56%) and normalized IGF-I levels in 48 patients (55%). The success rate was significantly increased compared with that before surgery (P < 0.0001). GH (r = -0.48; P < 0.0001) and IGF-I levels (r = -0.38; P = 0.0003) after postsurgery SSA treatment correlated with the amount of tumor surgically removed. After surgery, pituitary function was impaired in 28 patients (32.6%) and was improved in 12 patients (13.9%). The cumulative prevalence of pituitary deficiency did not change during the study (normal function from 40 to 42%; deficiency from 60 to 58%).

CONCLUSIONS

Surgical tumor removal (>75%) enhances the response to SSAs without impairing pituitary function. Our data indicate that surgical debulking has a significant place in the treatment algorithm of acromegaly.