Temozolomide and pasireotide treatment for aggressive pituitary adenoma: expertise at a tertiary care center.

Aggressive pituitary adenomas (PAs) are clinically challenging for endocrinologists and neurosurgeons due to their locally invasive nature and resistance to standard treatment (surgery, medical or radiotherapy). Two pituitary-directed drugs have recently been proposed: temozolomide (TMZ) for aggressive PA, and pasireotide for ACTH-secreting PA. We describe the experience of our multidisciplinary team of endocrinologists, neurosurgeons, neuroradiologists, oncologists, otolaryngologists and pathologists with TMZ and pasireotide treatment for aggressive PAs in terms of their radiological shrinkage and genetic features. We considered five patients with aggressive PA, three of them non-secreting (two ACTH-silent and one becoming ACTH secreting), and two secreting (one GH and one ACTH). TMZ was administrated orally at 150-200 mg/m(2) daily for 5 days every 28 days to all 5 patients, and 2 of them also received pasireotide 600-900 µg bid sc. We assessed the MRI at the baseline and during TMZ or pasireotide treatment. We also checked for MGMT promoter methylation and IDH, BRAF and kRAS mutations. Considering TMZ, two patients showed PA progression, one stable disease and two achieved radiological and clinical response. Pasireotide was effective in reducing hypercortisolism and mass volume, combined with TMZ in one case. Both treatments were generally well tolerated; one patient developed a grade 2 TMZ-induced thrombocytopenia. None of patients developed hypopituitarism while taking TMZ or pasireotide treatment. No genetic anomalies were identified in the adenoma tissue. TMZ and pasireotide may be important therapies for aggressive PA, alone or in combination.

Perioperative thromboprophylaxis in Cushing's disease: What we did and what we are doing?

PURPOSE: Cushing's disease (CD) is associated with an increased risk of thrombotic events, particularly after surgery. No guidelines are available on the management of patients with CD undergoing pituitary transsphenoidal surgery (TSS). We aimed to compare the effectiveness of different prophylactic procedures on the prevention of thrombotic events after surgery in CD. METHODS: We retrospectively collected data on 78 consecutive patients who underwent TSS for CD between 2001 and 2012 at Padova's Neurosurgical Unit, recording their hemostatic, hormonal and anthropometric parameters. Patients were divided into two groups according to their perioperative management. Group A (34 patients) received fractionated heparin for a maximum of 14 days after surgery. Patients in group B (44 patients) were given no early glucocorticoid replacement therapy, and treated with subcutaneous enoxaparin 4,000-8,000 U/daily (depending on their weight) for 30 days plus graduated elastic stockings until mobilization, and early ambulation. RESULTS: The whole cohort of patients had clotting and anticoagulant factors significantly higher than the normal range. The two groups were comparable for age, BMI, ACTH, urinary free cortisol levels, outcome of surgery, and main clotting parameters. The surgical procedure did not change during the study period. Three venous thrombotic events [venous thromboembolic events (VTE), 2 associated with pulmonary embolism] were recorded in group A, none in group B (p = 0.079). No hemorrhagic events were reported. CONCLUSIONS: Provoked thrombotic events pose a major problem in the management of CD patients after surgery, regardless of the procedure's outcome. The prophylactic regimen proposed in this paper afforded an efficacy prophylaxis against postoperative VTE in patients with CD. Due to the rarity of CD, a multicenter study on a larger sample of cases would be warranted in order to collect more thrombotic events.

Activation of the dopamine receptor type-2 (DRD2) promoter by 9-cis retinoic acid in a cellular model of Cushing's disease mediates the inhibition of cell proliferation and ACTH secretion without a complete corticotroph-to-melanotroph transdifferentiation.

Cushing's disease (CD) is a rare condition in which hypercortisolemia is secondary to excessive ACTH release from a pituitary corticotroph adenoma. CD is associated with significant morbidity and mortality, and a safe therapy that effectively targets the pituitary tumor is still lacking. Retinoic acid (RA) and dopamine agonists (DAs) have recently been considered as monotherapy in CD patients, and satisfactory results have been reported, albeit in a limited number of patients. Given the permissive role of RA on the dopamine receptor type-2 (DRD2), the aim of the present study was to see whether a combination of 9-cis RA and the DA bromocriptine (Br) might represent a possible treatment for CD. Here we show that 9-cis RA induces a functional DRD2 in the pituitary corticotroph cell line AtT20, and increases cell sensitivity to Br via a mechanism only partially related to corticotroph-to-melanotroph transdifferentiation. In addition, 9-cis RA and Br act synergistically to modulate cell viability, with favorable implications for clinical use. In nearly 45% of corticotropinoma-derived primary cultures, the combined administration of 9-cis RA and Br lowered the steady-state level of the ACTH precursor proopiomelanocortin (POMC) more efficiently than either of the drugs alone. In conclusion, the effects of a combination of 9-cis RA and Br on ACTH synthesis/secretion and cell viability in AtT20, and on POMC transcriptional activity in human corticotropinomas might represent a suitable starting point for assessing the potential of this treatment regimen for ACTH-secreting pituitary adenomas. This study thus has potentially important implications for novel therapeutic approaches to CD.

Association of craniopharyngioma and pituitary adenoma.

Intracranial tumors of different histologic types infrequently affect patients with pituitary adenomas and no history of head irradiation. The association with craniopharyngioma is extremely rare. Aims of this paper are: (1) to provide a critical literature review of typical features of pituitary adenoma presenting in association with craniopharyngioma; (2) to describe the first documented (clinically, biochemically, histologically, and radiologically) case of aggressive, suprasellar papillary craniopharyngioma presenting with amenorrhea, progressive reduction of visual field, and severe headache in a 38-year-old woman, a decade after surgical cure for microprolactinoma associated with empty sella, during which she had carried two pregnancies; and (3) to discuss common etiopathogenetic mechanisms, in relation to the management of these lesions. Systematic literature search for English literature focusing on the association of craniopharyngioma and pituitary adenoma was performed using PubMed database. Additional relevant articles from references lists were also included. Clinical, laboratory, and radiological examinations performed in our patient for the two brain lesions at diagnosis and follow up were collected. Literature search retrieved nine articles. Typically, craniopharyngioma were of adamantinomatous type, occurred simultaneously to pituitary adenoma, presented with headache and visual loss, and affected men. No case of clearly documented metachronous lesion affecting a woman after pregnancy had been described before. Although very rare and with uncertain etiopathogenesis, second tumors (i.e., craniopharyngioma) should be considered in patients with a history of pituitary adenoma, presenting with suggestive signs and symptoms, even after a long disease-free period, in order to provide proper and prompt treatment.

Predicting late recurrence in surgically treated patients with Cushing's disease.

OBJECTIVE: Cushing's disease (CD) has an uncertain prognosis because patients achieving remission after transsphenoidal pituitary neurosurgery (TSS) may relapse. We aimed to identify factors predicting relapse, focusing on desmopressin (DDAVP) and corticotropin-releasing hormone (CRH) tests after surgery. MATERIALS AND METHODS: Fifty-seven patients with CD (mean age 36 years) after TSS experienced remission (24 cases), late relapse (LR) (15 cases), or persistent disease (18 cases). RESULTS: The median time to relapse was 40 months. ACTH levels increased after both DDAVP and CRH stimulation, with a significantly higher response in the late recurrence group, showing this to be an indicator of increased risk of relapse. In the logistic regression model, a rise in ACTH >9 pg/ml after DDAVP and >36·7 pg/ml after CRH showed a sensitivity of 93% and 73%, respectively, a specificity of 82% and 76% in LR group. The area under the curve was 0·91 for DDAVP, 0·80 for CRH and 0·95 for DDAVP+CRH test, i.e. the combined tests performed better than each test alone, but not to a statistically significant degree. A response to both tests resulted in a positive predictive value (PPV) of 100%, while no response to either test in a negative predictive value (NPV) of 100%. CONCLUSIONS: ACTH hyper-responsiveness to DDAVP stimulation proved a valuable indicator of relapsing patients with high sensitivity and specificity; in selected cases when a clear high increment of ACTH level is not evident, the CRH test might be used as additional tool to confirm the risk of future relapses.

Increased rate of intracranial saccular aneurysms in acromegaly: an MR angiography study and review of the literature.

BACKGROUND: The concurrence of intracranial aneurysms and acromegaly has been reported and debated previously. Our study in a large number of patients aimed to verify whether acromegaly patients carry a higher risk of harboring intracranial saccular aneurysms and to evaluate the possible relationship using clinical, laboratory, and imaging techniques. MATERIALS AND METHODS: A total of 152 of 161 consecutive acromegaly patients (median age, 55.7 yr; 82 females) underwent neuroimaging evaluation of the circle of Willis. Clinical data (disease duration and disease control, hypertension, smoking history, diabetes and dyslipidemia, previous surgery or radiotherapy, previous or current pharmacological therapy), laboratory findings (GH and IGF-I at onset and shortly before examination), and pituitary adenoma imaging features (size and invasiveness of the cavernous sinus) were recorded. RESULTS: Twenty-six patients (17.3%) harbored 40 newly diagnosed intracranial aneurysms; two other patients had previously undergone aneurysm clipping due to subarachnoid hemorrhage. Ten patients had multiple aneurysms; most of the aneurysms were located in the intracranial tract of the internal carotid artery (67.5%); no aneurysms belonged to the vertebrobasilar circulation. The presence of intracranial aneurysms correlated with GH serum values at disease onset (P < 0.05) and showed a trend to a positive correlation with poor disease control (P = 0.06); no other laboratory, clinical, and radiological findings correlated with the presence of intracranial aneurysms. CONCLUSIONS: GH serum excess seems to carry an increased risk of developing intracranial aneurysms. A neuroradiological evaluation of the intracranial circulation might therefore be considered in the diagnostic work-up of patients affected with acromegaly.

Effect of everolimus on cell viability in nonfunctioning pituitary adenomas.

CONTEXT: Pituitary adenomas can cause specific syndromes due to hormone excess and/or determine sellar mass symptoms. Pituitary cell growth can sometimes be influenced by medical therapy, such as for somatotroph adenomas treated with somatostatin analogs or prolactinomas treated with dopaminergic drugs. However, nonfunctioning pituitary adenomas (NFAs) are still orphans of medical therapy. Everolimus (RAD001), a derivative of rapamycin, is a well-known immunosuppressant drug, which has been recently shown to have antineoplastic activity in several human cancers. OBJECTIVE: The objective of the study was to investigate the possible antiproliferative effects of RAD001 in human NFAs. DESIGN: We collected 40 NFAs that were dispersed in primary cultures, treated without or with 1 nm to 1 microm RAD001, 10 nm cabergoline, 10 nm SOM230 (a somatostatin receptor multiligand), and/or 50 nm IGF-I. Cell viability and apoptosis were evaluated after 48 h, and vascular endothelial growth factor (VEGF) secretion was assessed after an 8-h incubation. Somatostatin and dopamine subtype 2 receptor expression was investigated by quantitative PCR. RESULTS: In 28 cultures (70%), Everolimus significantly reduced cell viability (by approximately 40%; P < 0.05 vs. control), promoted apoptosis (+30%; P < 0.05 vs. control), inhibited p70S6K activity (-20%), and blocked IGF-I proliferative and antiapoptotic effects. In selected tissues cotreatment with SOM230, but not cabergoline, exerted an additive effect. Everolimus did not affect VEGF secretion but blocked the stimulatory effects of IGF-I on this parameter. CONCLUSIONS: Everolimus reduced NFA cell viability by inducing apoptosis, with a mechanism likely involving IGF-I signaling but not VEGF secretion, suggesting that it might represent a possible medical treatment of invasive/recurrent NFAs.

Pasireotide, a multiple somatostatin receptor subtypes ligand, reduces cell viability in non-functioning pituitary adenomas by inhibiting vascular endothelial growth factor secretion.

Somatostatin (SRIF) analogs have been employed in medical therapy of non-functioning pituitary adenomas (NFA), with contrasting results. Previous evidence showed that SRIF can exert its antiproliferative effects by reducing vascular endothelial growth factor (VEGF) secretion and action, and that VEGF expression may be related to pituitary tumor growth. The aim of our study was to clarify the possible effects of a multireceptor SRIF ligand on VEGF secretion and cell proliferation in human NFA primary cultures. We assessed the expression of SRIF receptors (SSTR1-5), the in vitro effects on VEGF secretion, and on cell viability of SRIF and of the stable SRIF analog pasireotide (SOM230), which activates SSTR1, 2, 3, and 5. Twenty-five NFA were examined by RT-PCR for expression of alpha-subunit, SSTR, VEGF, and VEGF receptors 1 (VEGF-R1) and 2 (VEGF-R2). Primary cultures were tested with SRIF and with pasireotide. All NFA samples expressed alpha-sub, VEGF and VEGFR-1 and 2, while SSTR expression pattern was highly variable. Two different groups were identified according to VEGF secretion inhibition by SRIF. VEGF secretion and cell viability were reduced by SRIF and pasireotide in the 'responder' group, but not in the 'non-responder' group, including NFA expressing SSTR5. SRIF and pasireotide completely blocked forskolin-induced VEGF secretion. In addition, SRIF and pasireotide completely abrogated the promoting effects of VEGF on NFA cell viability. Our data demonstrate that pasireotide can inhibit NFA cell viability by inhibiting VEGF secretion, and suggest that the multireceptor-SSTR agonist pasireotide might be useful in medical therapy of selected NFA.

Late potentials and ventricular arrhythmias in acromegaly.

BACKGROUND: Sudden death and increased prevalence of ventricular arrhythmias have already been described in acromegaly. Although late potentials (LPs) have been proved to be a new technique in detecting patients at risk for ventricular tachyarrhythmias its use in acromegaly is still unknown. METHODS: We studied 70 acromegalic patients [32 males, 38 females; age 49+/-12 years (mean+/-S.D.)] and 70 control subjects age- and sex-matched [(35 males and 35 females; 46+/-12 years (mean+/-S.D.)]. Besides hormonal tests, we performed the following cardiovascular investigations: ECG, 24-h ECG Holter monitoring, echocardiography, and signal-averaged ECG (SAECG) time-domain analysis. RESULTS: LPs occurrence was significantly higher in acromegalic patients as compared to the control group (22.9% vs. 2.9%; p=0.001). A greater duration of disease in patients with positive LPs compared to negative ones was pointed out (18 vs. 12 years; p=0.024). In the group of acromegalic patients with positive LPs we observed a significant association with premature ventricular complexes (PVCs) detected by means of 24-h Holter ECG recording (13 out of 15 patients: 86.7%; p=0.024). The positivity or negativity of LPs proved to be significantly associated with Lown scale PVC trends recorded by 24-h Holter ECG (p=0.014). In the group of patients with left ventricular hypertrophy a significant and pathological worsening of SAECG signals (QRS, LAS, RMS) was documented. CONCLUSIONS: We observed a higher prevalence of LPs in acromegaly which significantly correlated with Lown scale of PVCs.

Evidence for differential effects of selective somatostatin receptor subtype agonists on alpha-subunit and chromogranin a secretion and on cell viability in human nonfunctioning pituitary adenomas in vitro.

Somatostatin (SRIF) analogs interacting with SRIF receptor (SSTR) subtypes SSTR2 and SSTR5 reduce hormone secretion of pituitary adenomas, but their antiproliferative effects are still controversial. We investigated the in vitro effects of SRIF and SSTR-selective agonists interacting with SSTR1 (BIM-23926), SSTR2 (BIM-23120), SSTR5 (BIM-23206), or both SSTR2 and SSTR5 (BIM-23244) on alpha-subunit and chromogranin A secretion and on cell viability of 12 nonfunctioning pituitary adenomas (NFA) expressing SSTR1, SSTR2, and SSTR5, as assessed by RT-PCR. Treatment with SRIF or BIM-23206 did not modify alpha-subunit and chromogranin A secretion, which was significantly inhibited by BIM-23926, BIM-23120, and BIM-23244. SRIF and BIM-23120 did not influence cell viability, which was significantly promoted by BIM-23206 and BIM-23244 and reduced by treatment with BIM-23926. These results demonstrate that, in the selected NFA, the SSTR1-selective agonist inhibits secretory activity and cell viability, the SSTR2-selective agonist inhibits secretion but not cell viability, and the SSTR5-selective agonist does not influence secretion but promotes cell viability. These data can explain the lack of inhibitory effects of currently used SRIF analogs and suggest that drugs acting potently and preferentially on SSTR1 might be useful for medical treatment of NFA.

Somatostatin receptor subtype 1 selective activation in human growth hormone (GH)- and prolactin (PRL)-secreting pituitary adenomas: effects on cell viability, GH, and PRL secretion.

Somatostatin (SRIF) analogs interacting with SRIF receptor subtype (SSTR) 2 and SSTR5 are known to reduce secretion in GH-secreting pituitary adenomas. We investigated the effects of SRIF and a SSTR1 selective agonist, BIM-23926, on GH and prolactin (PRL) secretion and cell viability in primary cultures deriving from 15 GH- and PRL-secreting adenomas expressing SSTR1. Quantitative RT-PCR showed SSTR1 mRNA mean levels of 6 +/- 2.2 x 10(4) molecules/ microg reverse-transcribed total RNA. SSTR2 and SSTR5 were frequently expressed (93.3%), on the contrary of SSTR3 (53.3%) and SSTR4 (6.7%). GH secretion was significantly reduced by SRIF and BIM-23926 (45 +/- 8.6% and 32 +/- 18.1% inhibition, respectively) as well as PRL secretion (16.1 +/- 4% and 19.7 +/- 3.5% inhibition, respectively). After treatment with SRIF and BIM-23926, cell viability was significantly reduced by 17.5 +/- 5% and 20 +/- 3.9%, respectively. SSTR1 mRNA levels correlated with the degree of GH and PRL secretion inhibition. These results demonstrate that SSTR1 selective activation inhibits hormone secretion and cell viability in GH- and PRL-secreting adenomas in vitro and suggest that SRIF analogs with affinity for SSTR1 may be useful to control hormone hypersecretion and reduce neoplastic growth of pituitary adenomas.