Disease control of acromegaly does not prevent excess mortality in the long term: results of a nationwide survey in Italy.

OBJECTIVE: This study aimed to assess the long-term outcome of patients with acromegaly. DESIGN: This is a multicenter, retrospective, observational study which extends the mean observation period of a previously reported cohort of Italian patients with acromegaly to 15 years of follow-up. METHODS: Only patients from the centers that provided information on the life status of at least 95% of their original cohorts were included. Life status information was collected either from clinical records or from the municipal registry offices. Standardized mortality ratios (SMRs) were computed comparing data with those of the general Italian population. RESULTS: A total of 811 patients were included. There were 153 deaths, with 90 expected and an SMR of 1.7 (95% CI 1.4-2.0, p < 0.001). Death occurred after a median of 15 (women) or 16 (men) years from the diagnosis, without gender differences. Mortality remained elevated in the patients with control of disease (SMR 1.3, 95% CI 1.1-1.6). In the multivariable analysis, only older age and high IGF1 concentrations at last available follow-up visit were predictors of mortality. The oncological causes of death outweighed the cardiovascular ones, bordering on statistical significance with respect to the general population. CONCLUSIONS: Mortality remains significantly high in patients with acromegaly, irrespectively of disease status, as long as the follow-up is sufficiently long with a low rate of patients lost to follow-up. Therapy strategy including radiotherapy does not have an impact on mortality. Oncological causes of death currently outweigh the cardiovascular causes.

Correction to: Pegvisomant in acromegaly: an update.

Unfortunately, in page 584, second column, the first sentence under the heading "Type of switch" has been published incorrectly. The complete correct sentence is given below.

Pegvisomant in acromegaly: an update.

BACKGROUND: In 2007, we published an opinion document to review the role of pegvisomant (PEG) in the treatment of acromegaly. Since then, new evidence emerged on the biochemical and clinical effects of PEG and on its long-term efficacy and safety. AIM: We here reviewed the emerging aspects of the use of PEG in clinical practice in the light of the most recent literature. RESULTS: The clinical use of PEG is still suboptimal, considering that it remains the most powerful tool to control IGF-I in acromegaly allowing to obtain, with a pharmacological treatment, the most important clinical effects in terms of signs and symptoms, quality of life and comorbidities. The number of patients with acromegaly exposed to PEG worldwide has become quite elevated and the prolonged follow-up allows now to deal quite satisfactorily with many clinical issues including major safety issues, such as the concerns about possible tumour (re)growth under PEG. The positive or neutral impact of PEG on glucose metabolism has been highlighted, and the clinical experience, although limited, with sleep apnoea and pregnancy has been reviewed. Finally, the current concept of somatostatin receptor ligands (SRL) resistance has been addressed, in order to better define the acromegaly patients to whom the PEG option may be offered. CONCLUSIONS: PEG increasingly appears to be an effective and safe medical option for many patients not controlled by SRL but its use still needs to be optimized.

A multicenter experience on the prevalence of ARMC5 mutations in patients with primary bilateral macronodular adrenal hyperplasia: from genetic characterization to clinical phenotype.

ARMC5 mutations have recently been identified as a common genetic cause of primary bilateral macronodular adrenal hyperplasia (PBMAH). We aimed to assess the prevalence of ARMC5 germline mutations and correlate genotype with phenotype in a large cohort of PBMAH patients. A multicenter study was performed, collecting patients from different endocrinology units in Italy. Seventy-one PBMAH patients were screened for small mutations and large rearrangements in the ARMC5 gene: 53 were cortisol-secreting (two with a family history of adrenal hyperplasia) and 18 were non-secreting cases of PBMAH. Non-mutated and mutated patients' clinical phenotypes were compared and related to the type of mutation. A likely causative germline ARMC5 mutation was only identified in cortisol-secreting PBMAH patients (one with a family history of adrenal hyperplasia and ten apparently sporadic cases). Screening in eight first-degree relatives of three index cases revealed four carriers of an ARMC5 mutation. Evidence of a second hit at somatic level was identified in five nodules. Mutated patients had higher cortisol levels (p = 0.062), and more severe hypertension and diabetes (p < 0.05). Adrenal glands were significantly larger, with a multinodular phenotype, in the mutant group (p < 0.01). No correlation emerged between type of mutation and clinical parameters. ARMC5 mutations are frequent in cortisol-secreting PBMAH and seem to be associated with a particular pattern of the adrenal masses. Their identification may have implications for the clinical care of PBMAH cases and their relatives.

Acromegaly Is More Severe in Patients With AHR or AIP Gene Variants Living in Highly Polluted Areas.

CONTEXT: An increased prevalence of acromegaly was found some years ago in a highly polluted area in North-Eastern Sicily, where high concentration of nonmethane hydrocarbons, volatile organic compounds, and cadmium was found. Aryl hydrocarbon receptor (AHR) pathway has a key role in detoxification of these compounds and in tumorigenesis. OBJECTIVE: We correlated the occurrence of AHR and/or AHR-interacting protein (AIP) gene variants with acromegaly severity according to pollution exposition. DESIGN, SETTING, and PATIENTS: This was an observational, perspective study conducted over 7 years in four Italian referral centers for pituitary diseases in which 210 patients with acromegaly were enrolled between 2008 and 2015. INTERVENTION: Genetic screening of patients for AHR and AIP variants. MAIN OUTCOME MEASURES: Clinical, biochemical, and radiological data of patients with and without AIP and/or AHR gene variants, living in polluted (high-risk for health, [HR]) or nonpolluted (NP) areas of five Italian regions were evaluated and compared. RESULTS: Among the 23 patients from HR areas, nine showed AHR or AIP variants. Mean IGF-I levels and pituitary tumor diameter were significantly higher in these nine patients (HR/VAR+) than in the other 14 (HR/VAR−) and in the 187 from NP areas (44 NP/VAR+). Somatostatin analogs significantly decreased mean GH and IGF-I levels in patients from NP areas and in HR/VAR− (GH P < .05; IGF-I times the upper limit of normal P < .01) but not in HR/VAR+ group. CONCLUSIONS: Genetic variants potentially inducing functional abnormalities of the aryl hydrocarbon receptor (AHR) pathway are associated with a more severe acromegaly, increased pituitary tumor size, and somatostatin analog resistance in patients living in HR areas.

Analysis of GPR101 and AIP genes mutations in acromegaly: a multicentric study.

This multicentric study aimed to investigate the prevalence of the G protein-coupled receptor 101 (GPR101) p.E308D variant and aryl hydrocarbon receptor interacting protein (AIP) gene mutations in a representative cohort of Italian patients with acromegaly. 215 patients with GH-secreting pituitary adenomas, referred to 4 Italian referral centres for pituitary diseases, have been included. Three cases of gigantism were present. Five cases were classified as FIPA. All the patients have been screened for germline AIP gene mutations and GPR101 gene p.E308D variant. Heterozygous AIP gene variants have been found in 7 patients (3.2 %). Five patients carried an AIP mutation (2.3 %; 4 females): 3 patients harboured the p.R3O4Q mutation, one had the p.R304* mutation and the last one the IVS3+1G>A mutation. The prevalence of AIP mutations was 3.3 % and 2.8 % when considering only the patients diagnosed when they were <30 or <40-year old, respectively. Furthermore, 2.0 % of the patients with a pituitary macroadenoma and 4.2 % of patients resistant to somatostatin analogues treatment were found to harbour an AIP gene mutation. None of the patients was found to carry the GPR101 p.E308D variant. The prevalence of AIP gene mutations among our sporadic and familial acromegaly cases was similar to that one reported in previous studies, but lower when considering only the cases diagnosed before 40 years of age. The GPR101 p.E308D change is unlikely to have a role in somatotroph adenomas tumorigenesis, since none of our sporadic or familial patients tested positive for this variant.

Increased frequency of the rs2066853 variant of aryl hydrocarbon receptor gene in patients with acromegaly.

CONTEXT: Aryl hydrocarbon receptor (AHR) pathway has a key role in cellular detoxification mechanisms and seems implicated in tumorigenesis. Moreover, polymorphisms and mutations of AHR gene have been associated with several human and animal tumours. Although AHR has been found differently expressed in pituitary adenomas, AHR gene mutation status has never been investigated in acromegalic patients. DESIGN: In this study, we evaluated patients with apparently sporadic GH-secreting pituitary adenoma for AHR gene variants. PATIENTS AND METHODS: Seventy patients with sporadic GH-secreting pituitary adenoma (M = 27, age 59.1 ± 1.6 years) and 157 sex- and age-matched controls were enrolled in the study. In all patients and controls, the exons 1, 2, 3, 5 and 10 of AHR gene were evaluated for nucleotide variants by sequencing analysis. RESULTS: The rs2066853 polymorphism was identified in the exon 10 of 18/70 acromegalic patients and 9/157 healthy subjects (25.7 vs. 5.7%, χ(2) = 18.98 P < 0.0001), in homozygosis in one patient and in heterozygosis in the other 17 and in the 9 healthy subjects. Moreover, a heterozygous rs4986826 variant in exon 10 was identified in a patient with heterozygous rs2066853 polymorphism, and in the patient with homozygous rs2066853 variant. This second polymorphism was not detected in the control group. Patients with rs2066853 polymorphism showed increased IGF-1 ULN (P < 0.05) and prevalence of cavernous sinus invasion (P = 0.05), thyroid (P = 0.02), bladder (P = 0.0001) or lymphohematopoietic (P < 0.05) tumours. CONCLUSIONS: AHR gene rs2066853 polymorphism is significantly more frequent in acromegalic patients than in healthy subjects and is associated with increased disease aggressivity. Moreover, the rs4986826 variant was detected in few patients with rs2066853 polymorphism, but its role is to be cleared.

Predictors of morbidity and mortality in acromegaly: an Italian survey.

OBJECTIVE: To describe demographic and hormonal characteristics, comorbidities (diabetes mellitus and hypertension), therapeutic procedures and their effectiveness, as well as predictors of morbidity and mortality in a nationwide survey of Italian acromegalic patients. DESIGN: Retrospective multicenter epidemiological study endorsed by the Italian Society of Endocrinology and performed in 24 tertiary referral Italian centers. The mean follow-up time was 120 months. RESULTS: A total of 1512 patients, 41% male, mean age: 45±13 years, mean GH: 31±37 µg/l, IGF1: 744±318 ng/ml, were included. Diabetes mellitus was reported in 16% of cases and hypertension in 33%. Older age and higher IGF1 levels at diagnosis were significant predictors of diabetes and hypertension. At the last follow-up, 65% of patients had a controlled disease, of whom 55% were off medical therapy. Observed deaths were 61, with a standardized mortality ratio of 1.13 95% (confidence interval (CI): 0.87-1.46). Mortality was significantly higher in the patients with persistently active disease (1.93; 95% CI: 1.34-2.70). Main causes of death were vascular diseases and malignancies with similar prevalence. A multivariate analysis showed that older age, higher GH at the last follow-up, higher IGF1 levels at diagnosis, malignancy, and radiotherapy were independent predictors of mortality. CONCLUSIONS: Pretreatment IGF1 levels are important predictors of morbidity and mortality in acromegaly. The full hormonal control of the disease, nowadays reached in the majority of patients with modern management, reduces greatly the disease-related mortality.

Assessment of the awareness and management of sleep apnea syndrome in acromegaly. The COM.E.TA (Comorbidities Evaluation and Treatment in Acromegaly) Italian Study Group.

In 2007 the Italian COM.E.T.A. (COMorbidities Evaluation and Treatment in Acromegaly) study group started to assess the application in a clinical setting of the Versailles criteria for management of acromegaly complications by a first questionnaire focusing on cardiovascular co-morbidities. A further questionnaire on sleep apnea syndrome (SAS) was delivered by the COM.E.T.A. study group to 107 endocrine centers in Italy. The results of our survey suggest that SAS is a well-known comorbidity even if its estimated prevalence is lower than in the literature. Polysomnography is the preferred tool for diagnosis. Control of SAS is considered relevant both for quality of life and co-morbidities. Continuous positive airway pressure is the cornerstone of therapy, but patients' acceptance may be critical. Control of GH/IGF-I secretion is important to improve SAS. Management of SAS requires cooperation between specialists.

The R304X mutation of the aryl hydrocarbon receptor interacting protein gene in familial isolated pituitary adenomas: Mutational hot-spot or founder effect?

BACKGROUND: Mutations in the aryl hydrocarbon receptor interacting protein (AIP) gene have been described in about 15% of kindreds with familial isolated pituitary adenomas and in a minority of early onset sporadic pituitary adenomas (PA). Among the AIP mutations reported so far, the R304X (AIPR304X) represents, together with the "Finnish mutation" Q14X, the most common one. METHODS: Three AIPR304X Italian families, including a newly reported kindred, have been genotyped for 12 genetic markers surrounding the AIP gene in order to look for a potential founder effect in Italy. Disease penetrance and genotype-phenotype correlations were also addressed. RESULTS: Analysis of chromosome 11' genetic markers revealed a common haplotype in 2 AIPR304X kindreds originating from central Italy. Overall, 17 mutations carriers were identified, including 7 patients and 10 unaffected subjects, respectively, arguing in this case for a disease penetrance of 41%. Mean age at diagnosis was 19.1±6.7 yr old, with females tending to be older than males. Though most PA were somatotropinomas (6/7), a great variability in disease severity was observed, even between subjects sharing the same at-risk haplotype. CONCLUSION: These data provide strong evidence for a new founder effect of the AIPR304X mutation in central Italy and the observed variations in disease severity point out the role of additional genetic or environmental factors in such kindreds.

Assessment of the awareness and management of cardiovascular complications of acromegaly in Italy. The COM.E.T.A. (COMorbidities Evaluation and Treatment in Acromegaly) Study.

BACKGROUND: During the course of acromegaly, cardiovascular, respiratory, and metabolic co-morbidities contribute to enhanced mortality. In 2002, the Pituitary Society and the European Neuroendocrine Association sponsored a Consensus Workshop in Versailles during which guidelines for diagnosis and treatment of co-morbidities in acromegaly were defined. However, as for other guidelines previously issued in the field, no data are available on their clinical application. AIM: The aim of this work coordinated by the Italian Study group on co-morbidities evaluation and treatment in acromegaly (COM.E.T.A.) was to assess, on a national basis, the application in the clinical practice of the Versailles criteria for diagnosis and treatment of cardiovascular comorbities in acromegaly. MATERIALS AND METHODS: In January 2007 an ad hoc designed questionnaire was sent by mail to 130 endocrine Centers in Italy. RESULTS: The guidelines have been generally well perceived and translated in clinical practice. Specifically: 1) echocardiography is considered the mainstay for the diagnosis and follow-up; 2) ambulatory blood pressure monitoring and blood lipid assessment are performed in most hypertensive patients; 3) most endocrinologists directly manage hypertension and are aware of the uncertainty of the effect of the control of the disease on blood pressure levels; 4) ACE inhibitors and angiotensin receptors blockers are first-choice anti-hypertensive treatment; 5) approximately half of the centers consider somatostatin analogues of paramount relevance for biochemical control of disease; 6) awareness that left ventricular hypertrophy and heart failure are the most relevant cardiovascular complications is high although the impact of ischemic, arrhythmic, and valvular complications on prognosis is less well perceived. CONCLUSION: The results of the present survey suggest that previuosly issued guidelines are generally carefully followed in the clinical practice. On the other side, a certain lack of awareness of emerging aspects of the cardiovascular comorbities of acromegaly confirms the necessity of periodically updating the guidelines based on the availability of new clinical information.

Adrenal morpho-functional alterations in patients with acromegaly.

Acromegaly is associated with a greater morbidity and higher incidence of tumors, possibly due to the permissive role of elevated GH and IGF-I levels. In the general population, adrenal masses are frequently discovered (prevalence 1-5%) at computed tomography (CT). We evaluated the prevalence of adrenal lesions in patients with acromegaly. We studied 94 acromegalic patients, 54 females (mean age 55.0+/-16.0 yr) and 40 males (mean age 50+/-14 yr) referred to 5 Endocrinology Units between 2001-2003; 49 had active disease and 45 had been treated with surgery and/or were controlled with medical therapy. Abdominal CT showed adrenal lesions in 27 patients; 9 of them had unilateral masses (10%) with benign features (diameter 0.5-3 cm) and 18 had hyperplasia (14 monolateral and 4 bilateral), with no significant differences between patients with active vs controlled disease, and with no correlation between prevalence of masses and duration of disease, GH and IGF-I levels. Hormone study (urinary free cortisol, catecholamines/metanephrines, upright plasma renin activity and aldosterone, morning plasma ACTH and low-dose dexamethasone suppression test) disclosed no major endocrine alterations. During a 1-yr follow-up, the adrenal masses increased in size in 3 cases and 1 patient also developed subclinical Cushing's syndrome. Adrenal lesions seem more frequent in acromegaly than in the general population, but no single factor (GH/IGF-I levels or disease duration) predicts them. The masses appear to be benign and nonhypersecreting, but a longer follow-up is recommended to disclose any changes in their morphofunctional state.

Biochemical evaluation of patients with active acromegaly and type 2 diabetes mellitus: efficacy and safety of the galanin test.

The oral glucose tolerance test, which is considered the gold standard for the diagnosis of active acromegaly, should not be performed in the presence of basal hyperglycemia. Moreover, false-positive responses may occur in patients with diabetes mellitus. Galanin has previously been demonstrated to induce paradoxical inhibition of growth hormone (GH) secretion in most patients with active acromegaly. In this study, we assessed GH response to galanin infusion in a series of 17 consecutive patients with active acromegaly, 7 of whom had coexistent type 2 diabetes mellitus and 10 were without either diabetes mellitus or impaired tolerance to glucose. 6 acromegalic patients with diabetes mellitus (85.7%) and 7 without diabetes (70.0%) showed a decrease in serum GH values during galanin infusion (chi2 0.9; p = 0.6). The GH nadir occurred at a comparable time in the two groups of acromegalic patients. Moreover, the two groups showed no significant difference (p = 0.45) in DeltaGH during galanin infusion. Galanin infusion did not induce any significant change in plasma glucose levels in both diabetic and non-diabetic patients with acromegaly. The results of our study provide evidence that the galanin test may be of value for the diagnosis of acromegaly in patients with type 2 diabetes mellitus.

Development of acromegaly in a patient with anorexia nervosa: pathogenetic and diagnostic implications.

Anorexia nervosa (AN) is a psychosomatic disorder characterized by an alteration in body image, resulting in eating abnormalities that lead to malnutrition associated with secondary endocrinological disturbances. AN is associated with high levels of GH and low levels of IGF-I, suggestive of a nutritionally acquired lack of GH action or GH resistance and of an unbalanced hypothalamic GH neuroregulation with GHRH prevalence on SS tone. In this clinical report, we describe the development of acromegaly in a patient affected by AN and we discuss pathogenetic and diagnostic implications.

Clinical characterization of familial isolated pituitary adenomas.

CONTEXT: Familial pituitary adenomas occur rarely in the absence of multiple endocrine neoplasia type 1 (MEN1) and Carney complex (CNC). OBJECTIVE: Our objective was to characterize the clinical and genealogical features of non-MEN1/CNC familial isolated pituitary adenomas (FIPA). DESIGN AND SETTING: We conducted a retrospective study of clinical and genealogical characteristics of FIPA cases and performed a comparison with a sporadic population at 22 university hospitals in Belgium, Italy, France, and The Netherlands. RESULTS: Sixty-four FIPA families including 138 affected individuals were identified [55 prolactinomas, 47 somatotropinomas, 28 nonsecreting adenomas (NS), and eight ACTH-secreting tumors]. Cases were MEN1/PRKAR1A-mutation negative. First-degree relationships predominated (75.6%) among affected individuals. A single tumor phenotype occurred in 30 families (homogeneous), and heterogeneous phenotypes occurred in 34 families. FIPA cases were younger at diagnosis than sporadic cases (P = 0.015); tumors were diagnosed earlier in the first vs. the second generation of multigenerational families. Macroadenomas were more frequent in heterogeneous vs. homogeneous FIPA families (P = 0.036). Prolactinomas from heterogeneous families were larger and had more frequent suprasellar extension (P = 0.004) than sporadic cases. Somatotropinomas occurred as isolated familial somatotropinoma cases and within heterogeneous FIPA families; isolated familial somatotropinoma cases represented 18% of FIPA cases and were younger at diagnosis than patients with sporadic somatotropinomas. Familial NS cases were younger at diagnosis (P = 0.03) and had more frequently invasive tumors (P = 0.024) than sporadic cases. CONCLUSIONS: Homogeneous and heterogeneous expression of prolactinomas, somatotropinomas, NS, and Cushing's disease can occur within families in the absence of MEN1/CNC. FIPA and sporadic cases have differing clinical characteristics. FIPA may represent a novel endocrine neoplasia classification that requires further genetic characterization.

Hypopituitarism and growth hormone deficiency (GHD) after traumatic brain injury (TBI).

In adults, hypopituitarism and growth hormone deficiency (GHD) should be suspected and diagnosed within an appropriate clinical context. It has been demonstrated that all patients with primary hypothalamic-pituitary diseases before and after any medical intervention (defined as neurosurgery, radiotherapy and medical therapy) are at obvious risk - more than just at high risk - for hypopituitarism (greater than 80% had severe GHD). The same obvious risk applies to patients diagnosed as having congenital or acquired GHD in childhood (between 30% and 50% of patients with severe GHD after retesting). Taking into account the fragility of the infundibular-hypothalamic structure, patients with other common pathological conditions of the central nervous system (CNS), such as traumatic brain injury (TBI), subarachnoid haemorrhage (SAH) or primary brain tumours (BT) with related medical intervention could be at risk for developing hypopituitarism, including GHD. GHD is the first and most common sign of pituitary impairment. Despite the risk of pituitary dysfunction and the results of some studies that these risks are greater than previously believed, neuroendocrine evaluations are still not routinely included as part of the clinical management plan for patients with TBI and SAH. Preliminary results of a multicenter study performed under the auspices of the Italian Society of Endocrinology underscore the high risk of hypopituitarism and GHD under these clinical conditions. Thus, careful screening of pituitary function should always be performed in patients following TBI and SAH.

Long-term results of treatment in patients with ACTH-secreting pituitary macroadenomas.

OBJECTIVE: Since Cushing's disease due to large pituitary tumors is rare, we evaluated biochemical characteristics at entry and the results of first surgical approach and of adjuvant therapeutic strategies during a long-term follow-up period. DESIGN: We studied 26 patients (nine male, 17 female; 42.5+/-12.7 years, mean+/-s.e.) with ACTH-secreting pituitary macroadenoma (tumor diameter: 11-40 mm). METHODS: At entry, plasma ACTH, serum cortisol and 24-h urinary free cortisol (UFC) levels were measured in all patients, a high-dose dexamethasone (dexa) suppression test was evaluated in 22 cases and a corticotrophin releasing hormone (CRH) test in 20 cases. Patients were re-evaluated after operation and, when not cured, they underwent second surgery, radiotherapy and/or ketoconazole treatment. The follow-up period was 78+/-10 months. RESULTS: Before surgery, dexa decreased ACTH (>50% of baseline) in only 14/22 patients. The CRH-stimulated ACTH/cortisol response was normal in six patients, impaired in six patients and exaggerated in eight patients. After operation eight patients were cured, nine had normalized cortisol levels and nine were not cured. Pre-surgery, mean ACTH values were significantly higher in the not cured patients than in those normalized (P<0.05) and cured (P<0.01); the ACTH response to CRH was impaired in only six patients of the not cured group. The tumour diameter was significantly less in cured patients (P<0.02) and in normalized patients (P<0.05) than in the not cured ones. Magnetic resonance imaging (MRI) showed invasion of the cavernous sinus in 2/9 normalized, and in 6/9 not cured patients. After surgery, ACTH, cortisol and UFC were significantly lower than at entry in cured and in normalized patients, but not in not cured patients. In the cured group, the disease recurred in one patient who was unsuccessfully treated with ketoconazole. In the normalized group, a relapse occurred in eight patients: radiotherapy and ketoconazole induced cortisol normalization in one case, hypoadrenalism in one case and were ineffective in another one, while five patients were lost at follow-up. In the not cured group, eight patients underwent second surgery, radiotherapy and/or ketoconazole, while one patient was lost at follow-up. These therapies induced cortisol normalization in two patients and hypoadrenalism in one. CONCLUSIONS: (i) A sub-set of patients with ACTH-secreting pituitary macroadenoma showed low sensitivity to high doses of dexamethasone and to CRH, (ii) pituitary surgery cured Cushing's disease in a minority of patients, (iii) high baseline ACTH levels, impaired ACTH response to CRH, increased tumor size or invasion of the cavernous sinus were unfavourable prognostic factors for surgical therapy, and (iv) second surgery, radiotherapy and/or ketaconazole cured or normalized hypercortisolism in half of the patients with recurrence or not cured.

Development of a meningioma in a patient with acromegaly during octreotide treatment: are there any causal relationships?

Somatostatin receptors are highly expressed in almost all meningiomas but in this setting their functional role is not clear. A 59-yr-old woman had been treated with octreotide after an unsuccessful operation for a GH-secreting pituitary adenoma. After 8 yr of treatment, a nuclear magnetic resonance (NMR) scan disclosed a 3 cm meningioma of the tentorium. Mean GH was 2.2 ng/ml and IGF-I 325 ng/ml. Meningioma was resected and tissue was digested to obtain tumor cell suspension. Aim of the study was to measure epidermal growth factor (EGF)-induced proliferation of cultured meningioma cells in the presence of either somatostatin or octreotide. Cells were grown to semiconfluency in Dolbecco's modified eagle medium (D-MEM) supplemented with 10% fetal calf serum (FCS). After 48 h in D-MEM without serum, the medium was replaced by fresh medium plus recombinant EGF (10 ng/ml) and somatostatin or octreotide were added in the final concentrations of 1, 10 and 100 nM. 20 h later 1 microcgCi of 3H-thymidine was added to each well. After 4 h, incorporated radioactivity was measured. While octreotide did not influence significantly cell growth at the three dose tested, somatostatin increased thymidine incorporation dose-dependently (peak 100 nM: 150% +/- 27% vs medium plus EGF, p<0.05). Octreotide effectively suppressed GH secretion in our acromegalic patient but is unlikely that its long-term use could have stimulated the growth of meningioma since it did not significantly influence the in vitro proliferation of the meningioma cells. These results suggest that somatostatin-mediated proliferative effect on meningioma cells is not mediated by the subtype 2 of the somatostatin receptor.