Rosa Maria Paragliola

The hypertension of Cushing's syndrome: controversies in the pathophysiology and focus on cardiovascular complications

Cushings syndrome is associated with increased mortality, mainly due to cardiovascular complications, which are sustained by the common development of systemic arterial hypertension and metabolic syndrome, which partially persist after the disease remission. Cardiovascular diseases and hypertension associated with endogenous hypercortisolism reveal underexplored peculiarities. The use of exogenous corticosteroids also impacts on hypertension and cardiovascular system, especially after prolonged treatment. The mechanisms involved in the development of hypertension differ, whether glucocorticoid excess is acute or chronic, and the source endogenous or exogenous, introducing inconsistencies among published studies. The pleiotropic effects of glucocorticoids and the overlap of the several regulatory mechanisms controlling blood pressure suggest that a rigorous comparison of in-vivo and in-vitro studies is necessary to draw reliable conclusions. This review, developed during the first ‘Altogether to Beat Cushings syndrome’ workshop held in Capri in 2012, evaluates the most important peculiarities of hypertension associated with CS, with a particular focus on its pathophysiology. A critical appraisal of most significant animal and human studies is compared with a systematic review of the few available clinical trials. A special attention is dedicated to the description of the clinical features and cardiovascular damage secondary to glucocorticoid excess. On the basis of the consensus reached during the workshop, a pathophysiology-oriented therapeutic algorithm has been developed and it could serve as a first attempt to rationalize the treatment of hypertension in Cushings syndrome.

Endocrine side-effects of anti-cancer drugs: mAbs and pituitary dysfunction: clinical evidence and pathogenic hypotheses

mAbs are established targeted therapies for several diseases, including hematological and solid malignancies. These agents have shown a favorable toxicity profile, but, despite their high selectivity, new typical side-effects have emerged. In cancer patients, pituitary dysfunction may be mainly due to brain metastases or primary tumors and to related surgery and radiotherapy. Anticancer agents may induce hypopituitarism in patients cured for childhood cancers. These agents infrequently affect pituitary function in adult cancer patients. Notably, hypophysitis, a previously very rare disease, has emerged as a distinctive side-effect of ipilimumab and tremelimumab, two mAbs inhibiting the cytotoxic T-lymphocyte antigen-4 receptor, being occasionally seen with nivolumab, another immune checkpoint inhibitor. Enhanced antitumor immunity is the suggested mechanism of action of these drugs and autoimmunity the presumptive mechanism of their toxicity. Recently, ipilimumab has been licensed for the treatment of patients affected by metastatic melanoma. With the expanding use of these drugs, hypophysitis will be progressively encountered by oncologists and endocrinologists in clinical practice. The optimal management of this potentially life-threatening adverse event needs a rapid and timely diagnostic and therapeutic intervention. Hypopituitarism caused by these agents is rarely reversible, requiring prolonged or lifelong substitutive hormonal treatment. Further studies are needed to clarify several clinical and pathogenic aspects of this new form of secondary pituitary dysfunction.

Clinical accuracy of midnight salivary cortisol measured by automated electrochemiluminescence immunoassay method in Cushing's syndrome

Background The diagnosis of Cushings syndrome (CS) represents a challenge for endocrinologists. Several screening tests are used, but none of them seems to be the gold standard for the diagnosis. The aim of this study was to confirm the diagnostic value of salivary cortisol (SC) as a first-level screening test and to evaluate the clinical performance of a electrochemiluminescence immunoassay (ECLIA) method. Methods In 33 patients with a strong clinical suspicion of CS, we evaluated urinary free cortisol, circadian rhythm plasma cortisol (PC) and morning PC after low-dose dexamethasone suppression test (LDDST). At the same sampling times, we evaluated SC analysed by the same automated method. Correlation studies were evaluated by Spearman index (significance P < 0.05). Results On the basis of biochemical results CS was confirmed in 21/33. SC was significantly correlated to PC at 12:00 and 23:00. Thus, we chose 8.3 nmol/L as midnight SC cut-off value with 100% sensitivity and 97.4% specificity. The cut-off chosen after LDDST was 1.7 nmol/L (100% sensitivity and 72% specificity). Conclusion SC assay showed a good clinical accuracy and the ECLIA method can be used in clinical routine to obtain fast results easily.

The treatment of neuroendocrine tumors with long-acting somatostatin analogs: A single center experience with lanreotide autogel

The aim of this retrospective study was to evaluate the efficacy, safety, and tolerability of lanreotide autogel given to metastatic well-differentiated (WD) neuroendocrine tumors (NET) patients observed in our Institute between 2005 and 2008. Patients with metastatic NET referred to our tertiary referral center were given lanreotide autogel 120 mg/month by deep sc injection for a period of at least 24 months. The efficacy was evaluated by the relief of disease symptoms, behavior of tumor markers and response rate in terms of time to tumor progression. Safety and tolerability were evaluated by assessing the onset of adverse events and treatment feasibility. Twenty-three patients (13 males), median age 62 yr (range 32–87) were considered for the study. All patients were affected by WD metastatic NET and had tumor progression in the last 6 months before the enrolment in the study. Median duration of response was 28 months (range 6–50 months). Fourteen patients (60.9%) showed flushing and diarrhea which improved by 85.7% and 55.6%, respectively, bronchoconstrinction and abdominal pain also ameliorated. A complete, partial or no-changed response in the tumor markers behavior was observed, respectively, in 42.9%, 22.9%, and 17.1% of cases. According to RECIST (Response Evaluation Criteria In Solid Tumors) criteria (version 1.1), there were 2 partial regression (8.7%) and 15 stable disease (65.3%); 6 patients (26.0%) progressed. No patient complained from any severe adverse reaction. The results of our study suggest that lanreotide autogel is effective in the symptoms, biochemical markers, and tumor progression control of WD metastatic NET and confirm that the treatment is well tolerated.

Medullary thyroid cancer: a promising model for targeted therapy.

In recent years, the clinical validation of molecular targeted therapies inhibiting the action of pathogenic tyrosine kinase (TK) has been one of the most exciting developments in cancer research. In this context, medullary thyroid carcinoma (MTC) represents a promising model. It is well known that in MTC, the RET receptor TK and its signal transduction pathways, lead to subsequent neoplastic transformation. Several strategies aimed at blocking the activation and signaling of RET have been preclinically tested. The most advanced results have been obtained by competitive inhibition of RET-TK activity by tyrosine kinases inhibitors (TKI). However, although the inhibition of the RET pathway is actually one of the most studied for therapeutic purposes, other signal transduction pathways have been recognized to contribute to the growth and functional activity of MTC and are considered attractive therapeutic targets. To date, surgery represents the only curative treatment of MTC. Despite promising initial results, studies on targeted agents are in early stages and several issues regarding preclinical evaluations and clinical trials of new targeted agents in MTC are still unresolved. Now, available mouse models bearing mutations of RET or other genes, which spontaneously develop MTC, promise to improve preclinical evaluation of activity of targeted compounds. Furthermore, the rarity of the disease and the number of patients available for enrollment may lessen the relevance of clinical trials. A major effort needs to be made by endocrinologists and oncologists to refer their patients for multi-institutional trials in order to optimize them, perform translational studies and expedite the availability of novel beneficial selective therapies.

Thyroid scintigraphy: an old tool is still the gold standard for an effective diagnosis of autonomously functioning thyroid nodules

Background: Patients with autonomously functioning thyroid nodules (AFTN) may not have an abnormal TSH value, particularly in iodine-deficient areas. Aim: To verify the accuracy of TSH as screening test in detecting AFTN and to evaluate ultrasonographic features of thyroid nodules which have resulted autonomously functioning at thyroid scintigraphy (TS). Methods: Seventy-eight patients with nodular goiter, no marker of autoimmunity and at least one AFTN at TS were selected and divided in: Group 1 (no.=25) with TSH>0.35 IU/l, and Group 2 (no.=53) with TSH≤0.35 IU/l. Results: In Group1 the mean nodule diameter was 19.8±9.4 mm; 12 nodules were isoechoic, 2 hyperechoic, and 11 hypoechoic. Vascular pattern was type I in 4, type II in 6 and type III in 15 nodules. In Group 2 the mean nodule diameter was 28.6±14.2 mm; 27 nodules were isoechoic, 9 hyperechoic and 17 hypoechoic. Vascular pattern was type I in 14, type II in 15 and type III in 24 nodules. Conclusion: In our study TSH alone was not able to identify AFTN in 32% of the patients. All hot nodules predominantly showed an isoechoic pattern with peri-intranodular vascularization; however, the presence of this pattern was not statistically significant. Moreover, we noticed a weak inverse correlation between the diameter of AFTN and TSH level. In conclusion, TS is the most sensitive tool to detect AFTN, allowing a precocious diagnosis even in the presence of a normal TSH value.

Treatment of hypopituitarism in patients receiving antiepileptic drugs

Evidence suggests that there may be drug interactions between antiepileptic drugs and hormonal therapies, which can present a challenge to endocrinologists dealing with patients who have both hypopituitarism and neurological diseases. Data are scarce for this subgroup of patients; however, data for the interaction of antiepileptic drugs with the pituitary axis have shown that chronic use of many antiepileptic drugs, such as carbamazepine, oxcarbazepine, and topiramate, enhances hepatic cytochrome P450 3A4 (CYP3A4) activity, and can decrease serum concentrations of sex hormones. Other antiepileptic drugs increase sex hormone-binding globulin, which reduces the bioactivity of testosterone and estradiol. Additionally, the combined oestrogen-progestagen contraceptive pill might decrease lamotrigine concentrations, which could worsen seizure control. Moreover, sex hormones and their metabolites can directly act on neuronal excitability, acting as neurosteroids. Because carbamazepine and oxcarbazepine can enhance the sensitivity of renal tubules, a reduction in desmopressin dose might be necessary in patients with central diabetes insipidus. Although the effects of antiepileptic drugs in central hypothyroidism have not yet been studied, substantial evidence indicates that several antiepileptic drugs can increase thyroid hormone metabolism. However, although it is reasonable to expect a need for a thyroxine dose increase with some antiepileptic drugs, the effect of excessive thyroxine in lowering seizure threshold should also be considered. There are no reports of significant interactions between antiepileptic drugs and the efficacy of human growth hormone therapy, and few data are available for the effects of second-generation antiepileptic drugs on hypopituitarism treatment.

Cushing's Syndrome due to a Bronchial ACTH-Secreting Carcinoid Successfully Treated With Radiofrequency Ablation (RFA)

CONTEXT The ectopic production of ACTH is responsible for approximately 10% of cases of Cushings syndrome. Whenever possible, once hypercortisolemia is under control with medical therapy, the final treatment consists of surgical excision of the tumor. We report a case of a patient with high surgical risk and poor response to medical therapy in which hypercortisolemia has been successfully treated with radiofrequency ablation of the bronchial carcinoid tumor. CASE PRESENTATION A 43-year-old woman came to our hospital because of severe and rapidly worsening signs and symptoms of hypercortisolism over the previous 3 months. Hormonal tests suggested the presence of Cushings syndrome due to ectopic ACTH production. Imaging studies detected an 8-mm pulmonary nodule with fluorine-18-fluorodeoxyglucose uptake localized in the middle right lobe. The patient started therapy with ketoconazole with poor response. Middle right lobectomy was indicated but, due to the patients very high surgical risk, a thermal ablation with radiofrequency of the bronchial nodule was performed. OUTCOMES AND RESULTS After the procedure, ACTH and cortisol levels dropped and fluorine-18-fluorodeoxyglucose positron emission tomography showed complete response to treatment. Clinical conditions progressively improved, and 6 weeks later, the patient underwent middle lobectomy without complications. Histology showed a 0.7-cm ACTH-producing typical bronchial carcinoid tumor. CONCLUSIONS Thermal ablation with radiofrequency allows achieving a rapid control of hypercortisolism with subsequent improvement of symptoms. This procedure should therefore be considered as a viable therapeutic option in those cases of bronchial ACTH-secreting tumors in which the surgical approach is initially contraindicated.

mAbs and pituitary dysfunction: clinical evidence and pathogenic hypotheses

mAbs are established targeted therapies for several diseases, including hematological and solid malignancies. These agents have shown a favorable toxicity profile, but, despite their high selectivity, new typical side-effects have emerged. In cancer patients, pituitary dysfunction may be mainly due to brain metastases or primary tumors and to related surgery and radiotherapy. Anticancer agents may induce hypopituitarism in patients cured for childhood cancers. These agents infrequently affect pituitary function in adult cancer patients. Notably, hypophysitis, a previously very rare disease, has emerged as a distinctive side-effect of ipilimumab and tremelimumab, two mAbs inhibiting the cytotoxic T-lymphocyte antigen-4 receptor, being occasionally seen with nivolumab, another immune checkpoint inhibitor. Enhanced antitumor immunity is the suggested mechanism of action of these drugs and autoimmunity the presumptive mechanism of their toxicity. Recently, ipilimumab has been licensed for the treatment of patients affected by metastatic melanoma. With the expanding use of these drugs, hypophysitis will be progressively encountered by oncologists and endocrinologists in clinical practice. The optimal management of this potentially life-threatening adverse event needs a rapid and timely diagnostic and therapeutic intervention. Hypopituitarism caused by these agents is rarely reversible, requiring prolonged or lifelong substitutive hormonal treatment. Further studies are needed to clarify several clinical and pathogenic aspects of this new form of secondary pituitary dysfunction.

Somatostatin receptor ligands in acromegaly: clinical response and factors predicting resistance

IntroductionSomatostatin (SST) receptor ligands (SRL), in particular those of first generation (Octreotide and Lanreotide), are widely used in medical treatment of acromegaly, but they assure biochemical control of disease (and the possibility of an improvement of clinical symptoms and tumor shrinkage), only in a subset of patients.DiscussionThe mechanisms underlying the so called “SRL resistance” are various and involve in particular SST receptor expression and molecular pathways of signal transduction. Different predictors of SRL response have been reported, including clinical and biochemical features (gender, age, growth hormone and insulin-like growth factor-I levels at diagnosis), and tumor characteristic (both at preoperative magnetic resonance imaging study and histopathology) as well as expression of SST receptors. In some cases, only a “partial resistance” to SST can be detected, probably due to the presence of other impaired molecular mechanisms involved in signal transduction, which compromise specific pathways and not others. This may explain some cases of dissociated response between biochemical control and tumor shrinkage.