Diagnosis and treatment of pituitary tumors

Corneal parameters, ocular biometers, and retinal and choroidal thickness in acromegaly patients

BACKGROUND

To compare ocular findings of acromegaly patients with healthy individuals and investigate the relation of serum levels of insulin-like growth factor (IGF-1) along with growth hormone (GH) and pituitary tumor (adenoma) dimensions (TD) with specific ocular parameters.

METHODS

The ocular parameters of acromegaly patients (n = 38) were compared with those of healthy subjects (n = 36). These parameters were intraocular pressure, keratometric (K1-K2) values, central corneal thickness (CCT), total axial length along with anterior chamber-lens-vitreous length, retinal nerve fiber layer (RNFL) thickness, central foveal thickness (CFT), choroidal thickness (CT), ganglion cell layer thickness (GCLT), and inner plexiform layer thickness (IPLT). Also investigated was whether there was a correlation between disease duration, TD, GH, IGF-I, CCT, RNFL, CFT, GCLT, IPLT, and CT.

RESULTS

The lens length of the acromegaly group was increased (p = 0.014). GH and IGF-1 levels were positively correlated with CT and CCT, respectively (p = 0.041, r = 0.343) (p = 0.03, r = 0.347). Analysis of TD also found a highly negative correlation with the mean RNFL thickness of the acromegaly patients (p < 0.01, r = -0.603). The mean value of the inner parts of GCLT and IPLT was negatively correlated with TD (p = 0.041, r = -0.343 and p = 0.025, r = -0.379, respectively).

CONCLUSION

Serum IGF-1 and GH levels might be determinant factors in CCT and CT, respectively. The pituitary adenoma size increasing may be prone to lead RNFL, ganglion cell layer, inner plexiform layer thinning. Increased lens thickness was found in the acromegaly group.

Multidisciplinary Team Care in the Surgical Management of Pituitary Adenoma

Objective  Despite multidisciplinary care being commonly recommended, there remains limited evidence supporting its benefits in pituitary disease management. This study aimed to assess the impact of multidisciplinary care in pituitary surgery. Methods  A retrospective cohort study was performed comparing pituitary surgery outcomes among consecutive patients within a quaternary referral center in 5 years before and after introduction of a multidisciplinary team (MDT). Primary outcomes were endocrine (transient diabetes insipidus [DI], syndrome of inappropriate antidiuretic hormone [SIADH], and new hypopituitarism) and surgical (cerebrospinal fluid [CSF] leak, epistaxis, intracranial hemorrhage, and meningitis) complications, length of hospital stay, and intrasellar residual tumor. Results  279 patients (89 pre-MDT vs. 190 post-MDT) were assessed (age 54 ± 17 years, 48% female). Nonfunctioning adenomas were most common (54%). In the post-MDT era, more clinically functioning tumors (42 vs. 28%, p  = 0.03) were treated. Transient DI and SIADH occurred less often post-MDT (20 vs. 36%, p  < 0.01 and 18 vs. 39%, p  < 0.01), as well as new hypothyroidism (5 vs. 15, p  < 0.01). Hospital stay was shorter post-MDT (5[3] vs. 7[5] days, p  < 0.001) and intrasellar residuals were less common (8 vs. 35%, p  < 0.001). Complications were more frequent pre-MDT independent of tumor size, hormone status, and surgical technique (odds ratio [OR] = 2.14 [1.05-4.32], p  = 0.04). Conclusion  Outcomes of pituitary surgery improved after the introduction of an MDT. Pituitary MDTs may benefit both patients and the health system by improving quality of care and reducing hospital stays.

Case Report of a Pituitary Macroadenoma Treated With Artemether

Introduction: This report describes the case of a male patient with pituitary macroadenoma treated with the artemisinin analog artemether. Patient and Methods: A 75 year-old male patient presented with vision, hearing, and locomotion-related problems. Artemether was administered orally to the patient over a period of 12 months. Results: Although the tumor remained consistent in size, CT scan shows a reduction in its density, and clinically, the related symptoms and signs resolved significantly as therapy progressed. Discussion: Overall, the artemether treatment was beneficial in improving the patient's quality of life. Artemether and other artemisinin analogs offer promise for cancer therapy.

HIF-1α Inhibition Sensitized Pituitary Adenoma Cells to Temozolomide by Regulating Presenilin 1 Expression and Autophagy

Pituitary adenomas usually develop temozolomide resistance, which could compromise the anticancer effects of temozolomide. Suppression of hypoxia-inducible factor 1α has been shown to sensitize glioblastoma cells to temozolomide treatment according to previous reports. However, whether and how the suppression of hypoxia-inducible factor 1α could sensitize pituitary adenomas to temozolomide treatment are still poorly understood. In the present study, using hypoxia-inducible factor 1α knockdown strategy, we demonstrated for the first time that hypoxia-inducible factor 1α knockdown could inhibit temozolomide-induced autophagy in rat pituitary adenoma GH3 cells and thus increase antitumor efficacy of temozolomide. Furthermore, we found hypoxia-inducible factor 1α knockdown could block autophagy process through neutralizing lysosomal pH value but not inhibiting autophagy induction. Finally, we found hypoxia-inducible factor 1α could regulate lysosomal pH value through regulating full length presenilin 1 expression, and exogenous reexpression of presenilin 1could restore lysosome acidic levels. Our data indicated hypoxia-inducible factor 1α knockdown could be a potential approach to improve the efficacy of temozolomide therapy for pituitary adenomas.

Managing Cushing's disease: the state of the art

Cushing's disease is a rare chronic disease caused by a pituitary adenoma, which leads to excess secretion of adrenocorticotropic hormone (ACTH). The over-production of ACTH leads to hyperstimulation of the adrenal glands and a chronic excess of cortisol, resulting in the signs and symptoms of a severe clinical state (Cushing's syndrome) that leads to significant morbidity, negative impacts on the patient's quality of life, and, if untreated, increased mortality. The management of patients with Cushing's disease is complicated by the heterogeneity of the condition, with signs and symptoms that overlap with those of other diseases, and high subclinical incidence rates. Controversies surrounding the tests used for screening and identifying patients with Cushing's disease add to the challenge of patient management. Surgical intervention to remove the adenoma is the first-line treatment for patients with Cushing's disease, but medical therapies are useful in patients who relapse or are unsuitable for surgery. The recent introduction of pasireotide, the first pituitary-directed medical therapy, expands the number of treatment options available for patients with Cushing's disease. This state-of-the-art review aims to provide an overview of the most recent scientific research and clinical information regarding Cushing's disease. Continuing research into improving the diagnosis and treatment of Cushing's disease will help to optimize patient management.

HIF-1α inhibition sensitizes pituitary adenoma cells to temozolomide by regulating MGMT expression

Suppression of hypoxia-inducible factor 1α (HIF-1α) has been shown to sensitize glioblastoma cells to temozolomide (TMZ) treatment via down-modulation of O6-methylguanine-DNA methyltransferase (MGMT) expression. To date, whether the efficacy of TMZ therapy is correlated with MGMT expression and whether HIF-1α suppression exerts similar effects in human pituitary adenoma cells have not been defined. In the present study, using an HIF-1α knockdown strategy and the HIF-1α inhibitor 2-methoxyestradiol (2ME), we demonstrated for the first time that HIF-1α suppression increases the efficacy of TMZ in human pituitary adenoma cells in vitro and in vivo. Our mechanistic study showed that HIF-1α suppression resulted in down-modulation of MGMT expression and decreased DNA damage repair ability as demonstrated by decreased RAD51 protein expression. These results suggest an HIF-1α-dependent regulation of MGMT expression in human pituitary adenoma cells, and HIF-1α knockdown or the HIF-1α inhibitor 2ME can confer TMZ sensitization in human pituitary adenomas. The clinical application of 2ME as an adjuvant therapy may be a potential approach to improve the efficacy of TMZ therapy for pituitary adenomas.

Advances in pituitary imaging technology and future prospects

There have been substantial advances in pituitary imaging in the last half-century. In particular, magnetic resonance imaging is now established as the imaging modality of choice, providing high quality images of the hypothalamic-pituitary axis and adjacent structures. More recent technological advances, such as the emergence of 3 Tesla MRI, are already being widely incorporated into imaging practice. However, other advanced techniques, including a variety of potential imaging biomarkers, still require further research to evaluate their potential and define their precise role. The recent development of intraoperative MRI appears promising and may have the potential to improve the outcome of pituitary surgery. Modern high quality imaging inevitably leads to the discovery of incidental lesions, including those within the pituitary gland, although it also plays a central role in their subsequent evaluation and management.

Prolactin in men's health and disease

PURPOSE OF REVIEW

To review physiology of prolactin (PRL), cause and managment of hyperprolactinemia, and discuss evolving diverse roles of PRL in men's health.

RECENT FINDINGS

Hyperprolactinemia can be physiologically found after sexual activities, exercise, lactation, during pregnancy, and after stressful venipuncture. Elevated PRL can be caused by medications use, renal failure, hypothyroidism, and by prolactinoma - PRL secreting tumors. Symptomatic hyperprolactinemia and prolactinomas should be treated to lower PRL levels, decrease tumor size, and restore gonadal function. Three modes of treatment are typically utilized: pharmacological, radiosurgery with gamma radiation, and external beam radiation. Pharmacological treatment of prolactinomas is mainly based on dopamine agonists. The most frequently used dopamine agonists are bromocriptine and cabergoline. Cabergoline becoming the preferred drug in the treatment of prolactinomas because of higher response rate and less side-effects. Bromocriptine has been recently approved to improve glycemic control in diabetes mellitus.

SUMMARY

PRL plays a diverse role in men's reproduction and health. Detecting and treating elevated PRL may not only improve infertility and hypogonadism but also have a positive effect on the metabolic profile of patient and control of glycemic control and metabolic profile - an important advantage considering dramatic and worldwide increase in obesity and diabetes.

Anacardic acid induces caspase-independent apoptosis and radiosensitizes pituitary adenoma cells

OBJECT

Pituitary adenomas, which are common intracranial tumors, are associated with significant patient morbidity due to hormone secretion or mass effect or as a complication of therapy. Epigenetic regulation has emerged as an important component of malignant tumor pathogenesis, although the contribution in the progression of benign pituitary tumors remains largely unexplored. The present study evaluates the effect of anacardic acid (6-pentadecyl salicylic acid), a natural histone acetyltransferase inhibitor, on pituitary adenoma cells.

METHODS

The concentration- and time-dependent effects of anacardic acid on the viability of GH3 and MMQ pituitary adenoma cells were determined by 3-(4,5-dimethylthiazoyl-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell cycle phase distribution, protein expression, and percentage of apoptotic cells were assessed by flow cytometry and Western blotting. Colony forming assays were used to study the radiosensitizing effect of anacardic acid.

RESULTS

The present study identifies a novel antiproliferative and cytotoxic effect of anacardic acid on pituitary adenoma cells. These effects were associated with an increase in poly([adenosine diphosphate]-ribose) polymerase cleavage, sub-G1 arrest, and annexin V staining, consistent with apoptotic cell death; however, the pancaspase inhibitor carbobenzoxy-valyl-alanyl-aspartyl-(O-methyl)-fluoromethylketone failed to reverse anacardic acid-induced cell death, suggesting a possible nonclassical apoptotic mechanism. Anacardic acid also reduced the expression of survivin and X-linked inhibitor of apoptosis protein, antiapoptotic proteins associated with cellular survival and radioresistance, and radiosensitized pituitary adenoma cells.

CONCLUSIONS

These findings warrant further exploration of anacardic acid as a single agent or as an adjunct to radiation therapy for the treatment of pituitary tumors.

Radiation treatment strategies for acromegaly

The high morbidity and mortality associated with acromegaly can be addressed with multiple treatment modalities, including surgery, medicines, and radiation therapy. Radiation was initially delivered through conventional fractionated radiotherapy, which targets a wide area over many treatment sessions and has been shown to induce remission in 50%&#x2013;60% of patients with acromegaly. However, conventional fractionated radiotherapy takes several years to achieve remission in patients with acromegaly and carries a risk of hypopituitarism that may limit its use. Stereotactic radiosurgery, of which there are several forms, including Gamma Knife surgery, CyberKnife therapy, and proton beam therapy, offers slightly attenuated efficacy but achieves remission in less time and provides more precise targeting of the adenoma with better control of the dose of radiation received by adjacent structures such as the pituitary stalk, pituitary gland, optic chiasm, and cranial nerves in the cavernous sinus. Of the forms of stereotactic radiosurgery, Gamma Knife surgery is the most widely used and, because of its long-term follow-up in clinical studies, is the most likely to compete with medical therapy for first-line adjuvant use after resection. In this review, the authors outline the major modes of radiation therapies in clinical use today, and they critically assess the feasibility of these modalities for acromegaly treatment. Acromegaly is a multisystem disorder that demands highly specialized treatment protocols including neurosurgical and endocrinological intervention. As more efficient forms of pituitary radiation develop, acromegaly treatment options may continue to change with radiation therapies playing a more prominent role.

Radiosurgery for pituitary adenomas: evaluation of its efficacy and safety

Object

To assess the effects of radiosurgery (RS) on the radiological and hormonal control and its toxicity in the treatment of pituitary adenomas.

Methods

Retrospective analysis of 42 patients out of the first 48 consecutive patients with pituitary adenomas treated with RS between 1999 and 2008 with a 6 months minimum follow-up. RS was delivered with Gamma Knife as a primary or adjuvant treatment. There were 14 patients with non-secretory adenomas and, among functioning adenomas, 9 were prolactinomas, 9 were adrenocorticotropic hormone-secreting and 10 were growth hormone-secreting tumors. Hormonal control was defined as hormonal response (decline of more than 50% from the pre-RS levels) and hormonal normalization. Radiological control was defined as stasis or shrinkage of the tumor. Hypopituitarism and visual deficit were the morbidity outcomes. Hypopituitarism was defined as the initiation of any hormone replacement therapy and visual deficit as loss of visual acuity or visual field after RS.

Results

The median follow-up was 42 months (6-109 months). The median dose was 12,5 Gy (9 - 15 Gy) and 20 Gy (12 - 28 Gy) for non-secretory and secretory adenomas, respectively. Tumor growth was controlled in 98% (41 in 42) of the cases and tumor shrinkage ocurred in 10% (4 in 42) of the cases. The 3-year actuarial rate of hormonal control and normalization were 62,4% and 37,6%, respectively, and the 5-year actuarial rate were 81,2% and 55,4%, respectively. The median latency period for hormonal control and normalization was, respectively, 15 and 18 months. On univariate analysis, there were no relationships between median dose or tumoral volume and hormonal control or normalization. There were no patients with visual deficit and 1 patient had hypopituitarism after RS.

Conclusions

RS is an effective and safe therapeutic option in the management of selected patients with pituitary adenomas. The short latency of the radiation response, the highly acceptable radiological and hormonal control and absence of complications at this early follow-up are consistent with literature.

Endonasal transsphenoidal surgery and multimodality treatment for giant pituitary adenomas

OBJECTIVE

Giant pituitary adenomas (> or =40 mm) pose a major management challenge. We describe the experience of a single surgeon and a dedicated neuro-endocrine team with multimodality treatment of these tumours in three specialized institutions.

DESIGN

Retrospective data set analyses.

PATIENTS

Fifty-one consecutive patients with a giant adenoma (39 endocrine-inactive, 12 endocrine-active; mean tumour diameter 45 mm) treated over 10 years by an endonasal transsphenoidal approach were included. All patients had surgical resection followed by radiotherapy and/or medical therapy as judged necessary.

MEASUREMENTS

Hormonal and visual status, extent of resection, tumour control rates, complications and use of medical and radiotherapy were evaluated.

RESULTS

Surgery resulted in gross total, near total and subtotal removal in21 (41%), 10 (20%) and 20 (39%) patients respectively. Complete tumour removal was associated with absence of cavernous sinus invasion (P < 0.001). Long-term endocrine function improved in 49% of patients and new endocrinopathy occurred in 14.6%; 76% required long-term hormone replacement therapy. Vision improved in 81.5% of the patients and there was no visual worsening. At the last follow up (median 30 months), tumour control was achieved in 96% of patients: 59% with surgery alone, 20% with surgery plus focussed radiotherapy, 18% with surgery and medical therapy and two with all three modalities.

CONCLUSIONS

Endonasal surgery provides effective initial treatment for patients with giant adenomas. Multimodality therapy was needed in almost 50% of patients and this rate will likely increase with longer follow up. Close collaboration of neurosurgeons with endocrinologists and radiation oncologists is essential for optimal treatment of patients with these challenging tumours.

Pituitary macroadenoma presenting with brow mass and acromegaly

A 62-year-old woman presented with a brow mass and acromegaly. Biopsy of the lesion showed fibrous dysplasia. Radiologic imaging revealed a pituitary macroadenoma. The patient underwent transsphenoidal pituitary resection and radiation treatment, followed by medicalmanagement of endocrinopathy.

Pituitary adenomas in northern Sweden: a study on therapy choices and the risk of second primary tumours

OBJECTIVES

To present the incidence of pituitary adenomas in northern Sweden and to determine whether the incidence of second primary tumours differs from the incidence in the general population or might be related to radiotherapy.

DESIGN

A retrospective register study.

PATIENTS

A total of 546 patients with pituitary adenomas were identified in the Cancer Registry of northern Sweden between 1958 and 2004. Only patients with histopathological verification and/or endocrine activity of the adenoma and more than 12 months of follow-up were included, resulting in 376 patients in the study.

MEASUREMENTS

The number of patients receiving surgery and/or radiotherapy and presenting second primary tumours were registered. Standard incidence ratios (SIRs) between the observed and the expected incidence of second primary tumours were calculated.

RESULTS

The total number of person-years at risk for a second primary tumour was 4730. Fifty-four out of 376 (14%) patients had 63 second primary tumours. Forty patients had second primary tumours diagnosed more than 12 months after diagnosis of the pituitary adenoma (expected 42.6, SIR 0.94, 95% CI 0.67-1.28). A significantly increased incidence of second primary tumours was seen in 42 men with GH-secreting adenomas. Ten second tumours were found (expected 4.55, SIR 2.20, 95% CI 1.05-4.04). A total of 261 patients received radiotherapy and 31 second primary tumours occurred after radiotherapy (expected 32.9, SIR 0.94, 95% CI 0.64-1.34). Three second primary intracranial tumours appeared within the irradiation volume (expected 0.85, SIR 3.51, 95% CI 0.71-10.36).

CONCLUSIONS

No significant increase was found in the incidence of second primary tumours in general in patients with pituitary adenomas. An increased incidence of second primary tumours was seen in men with GH-secreting adenomas.

[Radiosurgery for pituitary adenomas]

Pituitary adenomas represent nearly 15% of all intracranial tumors. Multimodal treatment includes microsurgery, medical management and radiotherapy. Microsurgery is the primary recommendation for nonfunctioning and most of functioning adenomas, except for prolactinomas that are usually managed with dopamine agonist drugs. However, about 30% of patients require additional treatment after microsurgery for recurrent or residual tumors. In these cases, fractionated radiation therapy has been the traditional treatment. More recently, radiosurgery has been established as a treatment option. Radiosurgery allows the delivery of prescribed dose with high precision strictly to the target and spares the surrounding tissues. Therefore, the risks of hypopituitarism, visual damage and vasculopathy are significantly lower. Furthermore, the latency of the radiation response after radiosurgery is substantially shorter than that of fractionated radiotherapy. The goal of this review is to define the efficacy, safety and role of radiosurgery for treatment of pituitary adenomas and to present the preliminary results of our institution.

Reliability of neuronavigation-assisted trans-sphenoidal tumor resections

OBJECTIVE

To analyse the surgical reliability of neuronavigation-assisted trans-sphenoidal tumor resections.

METHOD

In the past 7 years, all patients, who underwent neuronavigation-assisted trans-sphenoidal tumor resection in our department, were additionally intraoperatively controlled with a radioscopic device. Tumor removal was repeatedly checked up with the navigator and the tip of the pointer was correlated with the lateral intraoperative skull radiologic examination to confirm the real pointer deepness, spatial location and trajectory. The reliability of these assessments was analysed by simple images comparison and searching for tumor-related differences, and controlled with post-operative magnetic resonance studies.

RESULTS

During the analysed period, a total of 36 patients were treated in our department. Diagnosis included 14 non-secreting adenomas, 18 secreting adenomas and four non-pituitary tumors. Tumors diameter ranged from 1.4 to 4.5 cm. A mean accuracy of 0.8 mm could be achieved for all patients. In all cases, the real deepness, position and trajectory of the navigator were identical to those observed with X-ray examinations. At least nine from ten pointer determinations were identical in all cases. Particularly, all pituitary tumors with suprasellar extension could be safely controlled, even during advanced stages of resection and before the tumor capsule detached from suprasellar neighbor structures. Intrasellar, clival and suprasellar tumors were adequately removed as confirmed with MRI.

CONCLUSIONS

Radioscopic controlled neuronavigation shows high reliability and allows surgeons to be more confident during the trans-sphenoidal resection of skull base tumors. This offers the advantage to reduce the patient's X-ray exposure and the possibility of simultaneous multiplanar images evaluation.

Peroxisome proliferator-activated receptor gamma in the human pituitary gland: expression and splicing pattern in adenomas versus normal pituitary

Pituitary adenomas are slow-growing tumours arising within the pituitary gland. If secreting, they give rise to well-known syndromes such as Cushing's disease or acromegaly; when hormonally inactive, they come to clinical attention often with local mass effects or pituitary deficiency. Peroxisome proliferator-activated receptor gamma (PPARgamma), a nuclear hormone receptor with a key role in fat and glucose metabolism, but also involved in several neoplasia, has recently been detected in pituitary adenomas. In the present study, we evaluated the occurrence and splicing profile of PPARgamma in 43 cases of pituitary adenoma of different subtypes and compared it to 12 normal pituitary glands. By real-time polymerase chain reaction, PPARgamma was expressed as much in adrenocorticotrophic hormone (ACTH)-secreting and ACTH-silent adenomas as in controls, with a moderate underexpression in somatotrophinomas and prolactinomas and overexpression in 54% of nonfunctioning pituitary adenomas (NFPA). There was no apparent qualitative change in the splicing profile of pathological pituitary glands, nor was the presence of specific isoforms with dominant negative effects against PPARgamma detected. Western blotting revealed similar expression levels in the different subgroups of pituitary adenomas and normal glands. Immunohistochemistry confirmed PPARgamma expression in approximately one-half of analysed samples. The intra- and intergroup differences observed in pituitary adenomas may represent new elements in the process of understanding the different clinical responses of Cushing's and Nelson patients to PPARgamma-ligand treatment. Moreover, the higher level of PPARgamma expression detected in the NFPA subgroup may suggest its possible role as a molecular target in these pituitary adenomas, paving the way for investigations on the effectiveness of treatment with thiazolidinediones in such patients.

Bromocriptine-responsive Cushing's disease; clinical and biochemical remission accompanied by amelioration of impaired ocular movement

A 73-year-old woman presented with disturbance of right eyelid opening with ptosis and impairment of right ocular movement, and later was found to have Cushingoid features. Endocrine examinations revealed that plasma ACTH and cortisol levels were elevated, lack of circadian rhythm, resistant to low-doses (0.5, 1, 2 mg) and high-dose (8 mg) dexamethasone, and responsive to CRH and DDAVP. Magnetic resonance imaging (MRI) revealed a large pituitary tumor invading the right cavernous sinus. After two months treated with bromocriptine (5 mg/day), she showed clinical improvement with normalization of plasma ACTH and cortisol levels, and improvement of right eyelid opening and ocular movement. MRI, however, revealed no apparent reduction in the size of pituitary tumor. This is a rare case of bromocriptine-responsive Cushing's disease.

Gene therapy for pituitary tumors

Pituitary tumors are the most common primary intracranial neoplasms. Although most pituitary tumors are considered typically benign, others can cause severe and progressive disease. The principal aims of pituitary tumor treatment are the elimination or reduction of the tumor mass, normalization of hormone secretion and preservation of remaining pituitary function. In spite of major advances in the therapy of pituitary tumors, for some of the most difficult tumors, current therapies that include medical, surgical and radiotherapeutic methods are often unsatisfactory and there is a need to develop new treatment strategies. Gene therapy, which uses nucleic acids as drugs, has emerged as an attractive therapeutic option for the treatment of pituitary tumors that do not respond to classical treatment strategies if the patients become intolerant to the therapy. The development of animal models for pituitary tumors and hormone hypersecretion has proven to be critical for the implementation of novel treatment strategies and gene therapy approaches. Preclinical trials using several gene therapy approaches for the treatment of anterior pituitary diseases have been successfully implemented. Several issues need to be addressed before clinical implementation becomes a reality, including the development of more effective and safer viral vectors, uncovering novel therapeutic targets and development of targeted expression of therapeutic transgenes. With the development of efficient gene delivery vectors allowing long-term transgene expression with minimal toxicity, gene therapy will become one of the most promising approaches for treating pituitary adenomas.

Novel therapeutic directions in Cushing's syndrome

Cushing's disease is the most common cause of endogenous hypercortisolemia. It is a rare disease of unknown etiology that is prone to relapse and damaging to quality of life, even in remission. A significant proportion of patients are not cured by primary surgical treatment, and adjuvant radiotherapy has become an increasingly unattractive proposition for clinicians who wish to spare their patients hypopituitarism and other potential complications. The few effective pharmacological options that are available currently tend to have dose-limiting side effects and new alternatives that are safer and more effective than the adrenal cortical enzyme inhibitors and adrenolytic drugs would be most welcome. This article discusses preliminary efficacy data for several potential new groups of drugs.