[New perspectives in diagnosis and therapy of endocrine gastroenteropancreatic (GEP) tumors with somatostatin analogues]

In the last decade important progresses have been obtained in the diagnosis and therapy of endocrine gastroenteropancreatic (GEP) tumors, mainly derived from the somatostatin receptors characterization and the introduction of long acting somatostatin analogues. Receptorial scintigraphy with radio-labeled analogues (Octreoscan) is the first choice investigation for staging and follow-up of endocrine GEP tumors, thanks to the high sensitivity in revealing the primary tumor and metastases, and for its capability to reveal lesions that are not identified by other imaging methods. Moreover, somatostatin analogues uptake by tumors allow us to use radiopharmaceutical compounds for advanced disease treatment. Between the radio-labeled drugs until now studied, interesting results have been obtained by DOTA-lanreotide (MAURITIUS), DOTA0 Tyr3-octreotide (DOTATOC) and DOTA0 Tyr3-octreotate, bound to beta-emitting radio-isotope suitable for therapeutic use. In the field of the pharmacological therapy of GEP tumors, the clinical trials show that somatostatin analogues reduce the symptoms related to functionally active tumors and stabilize or slow tumor growth improving the patient quality of life. Although somatostatin analogues alone could not be able to cure GEP tumors, their early utilization in association with surgical debulking of primary tumor and metastases, embolization or chemoembolization, and interferon, chemotherapy and radio-metabolic therapy (mainly directed to the destruction of micrometastases), increases the possibility of a radical therapeutic intervention. The continuous evolution of pharmacological research provides always new analogues (octreotide LAR, lanreotide, vapreotide, BIM-23244, BN 81644, PTR-3173, BIM-23A387, SOM-230, etc.) with different pharmacokinetic and receptorial properties and acting with more effectiveness in the different individual clinical situations. In this context there have been recently introduced also the "chimeric" analogues. On the other hand, the widespread utilization of molecular biology and immunohistochemical methods can allow, in perspective, to better define the receptorial pattern of individual endocrine tumors, after their surgical removal. The necessity to integrate endocrinological, nuclear medicine, surgical, oncologic and laboratory competencies behaves a multidisciplinary approach based on the utilization of diagnostic-therapeutic protocols supplying comparable results. It does not appear unjustified to expect, in the future, a scenery of more "individual" and more effective therapies for patients affected by GEP tumours.

Medullary thyroid cancer

Medullary thyroid cancer is a rare neoplasm that arises from the parafollicular C cells. It occurs in a sporadic form, or less commonly as a hereditary form, as part of multiple endocrine neoplasia syndromes types 2A and 2B. The RET proto-oncogene is currently the primary factor that is implicated in the hereditary forms of this neoplasm. The knowledge about the genetic makeup of the neoplasm impacts upon management as it allows for screening, early detection, and prophylactic treatment. Surgery is the main modality that offers a cure. This entails a total thyroidectomy and vigilant management and surveillance of the neck. Prognosis of patients with MTC is variable, but the more constant factors that affect it are the stage of disease and the age of the patient. The emerging molecular genetic understanding of this malignancy will provide the foundation for prognostic and therapeutic decision-making in the future. Interdisciplinary management by surgeons, endocrinologists, pathologists, radiotherapists, radiologists, and medical oncologists should be sought.

Endocrine tumors

Because of the diverse nature of endocrine organs, and their vast range of physiologic functions, endocrine tumors encompass a wide range of origination sites and disease entities. The clinical picture of affected individuals is highly dependent on the tissue of origin, and the presence or absence of functional hormone secretions. Identification, localization, and therapeutic strategies, as well as prognosis can vary greatly. Many endocrine tumors have been described in human as well as veterinary patients. This article focuses on endocrine tumors of dogs and cats. Various tumors affecting the pancreas, thyroid, parathyroid, adrenal and pituitary glands are described, including insulinoma, gastrinoma, glucagonoma, and thyroid carcinoma, as well as parathyroid hormone- and growth hormone-secreting tumors. The syndrome of multiple endocrine neoplasia is also described.

Risk-based management of solid tumors in children

BACKGROUND

During the past 25 years significant improvements in survival (56% to 75%) have been observed for children with malignant solid tumors. Multidisciplinary cooperative studies using combined therapy (surgery, chemotherapy, and irradiation) have played a major role. This report describes how recognition of biologic and genetic factors has permitted risk categorization and resulted in new treatment protocols that individualize care.

METHODS

Genetic alterations and biologic factors concerning the multiple endocrine neoplasia syndromes, Wilms' tumor, and neuroblastoma are described.

RESULTS

Using the these data new treatment protocols are designed according to whether a patient is categorized as having a low-, intermediate-, or high-risk tumor, which determines the intensity and type of treatment required.

CONCLUSIONS

Identification of biologic markers and specific gene alterations may be critical in establishing the behavior of tumors (low versus high-risk). Risk-based management permits individualized care for each patient, maximizes survival, minimizes morbidity, and improves the quality of life.

Multiple endocrine neoplasia type 2 and RET: from neoplasia to neurogenesis

Multiple endocrine neoplasia type 2 (MEN 2) is an inherited cancer syndrome characterised by medullary thyroid carcinoma (MTC), with or without phaeochromocytoma and hyperparathyroidism. MEN 2 is unusual among cancer syndromes as it is caused by activation of a cellular oncogene, RET. Germline mutations in the gene encoding the RET receptor tyrosine kinase are found in the vast majority of MEN 2 patients and somatic RET mutations are found in a subset of sporadic MTC. Further, there are strong associations of RET mutation genotype and disease phenotype in MEN 2 which have led to predictions of tissue specific requirements and sensitivities to RET activity. Our ability to identify genetically, with high accuracy, subjects with MEN 2 has revolutionised our ability to diagnose, predict, and manage this disease. In the past few years, studies of RET and its normal ligand and downstream interactions and the signalling pathways it activates have clarified our understanding of the roles played by RET in normal cell survival, proliferation, and differentiation, as well as in disease. Here, we review the current knowledge of the normal functions of RET and the effects of mutations of this gene in tumorigenesis and in normal development.

Multiple endocrine neoplasia (MEN)--an overview and case report--patient with sporadic bilateral pheochromocytoma, hyperparathyroidism and marfanoid habitus

The multiple endocrine neoplasia syndromes are divided into two categories: MEN type I and MEN type II. The MEN type II syndrome is further divided into MEN IIa and MEN IIb. The syndromes are characterized by benign and malignant changes in two or more endocrine organs, as well as incidental changes in nervous, muscular and connective tissue. Two main forms can be distinguished: the MEN-I syndrome with hyperplasia of the parathyroid gland, accompanied by islet cell tumor and pituitary adenoma; the MEN-II syndrome with medullary thyroid carcinoma in combination with bilateral pheochromocytoma and hyperplasia of the parathyroid gland (MEN IIa), while type IIb is characterized by the additional appearance of neurocutaneous manifestations without primary hyperparathyroidism. Characteristics shared by these syndromes include the involved cell type, most of the tumors are composed of one or more specific polypeptide- and biogenic amine-producing cell types (APUD--amine precursor uptake and decarboxylation). The second characteristic is the increased incidence in certain families. The hereditary component is autosomal dominant with variable expression but high penetrance. Mechanisms of tumorigenesis differ in these syndromes. While MEN I is caused by an inherited mutation of a tumor suppressor gene, menin, located on the long arm of chromosome 11, MEN II is caused by activation of the RET proto-oncogene. We have reported the case of a young man exhibiting bilateral pheochromocytoma. In addition, the patient showed mild primary hyperparathyroidism and marfanoid habitus, all these stigmata usually being part of the MEN-II syndrome. Although this described patient showed a phenotypic mixture of the MEN-IIa and MEN-IIb syndrome, the genetic analysis for MEN II and von-Hippel-Lindau gene did not reveal any pathologic mutations, the endocrine disorders described here are not related to multiple endocrine neoplasia syndromes.

Multiple endocrine neoplasias

Multiple endocrine neoplasia type 1 (MEN 1), and the multiple endocrine neoplasia type 2 syndromes (MEN 2A, MEN 2B, and familial non-MEN medullary thyroid carcinoma [FMTC]) encompass a wide range of endocrine problems, but arise from only two genes: the MEN 1 tumor suppressor gene and the RET proto-oncogene. MEN 1 is characterized by parathyroid hyperplasia, pancreaticoduodenal neuroendocrine tumors (PNTs), and pituitary adenomas. Surgery is the principal treatment modality for hyperparathyroidism and PNTs, but questions still remain concerning the timing and extent of surgery for PNTs. The MEN 2 syndromes are characterized by complete penetrance of medullary thyroid cancer. The MEN 2 syndromes differ in their variable expression of hyperparathyroidism, pheochromocytomas, and other clinical features. Genetic testing for mutations in the RET gene has revolutionized treatment by enabling thyroidectomies before significant disease occurs.

Medullary thyroid carcinoma: clinical characteristics, treatment, prognostic factors, and a comparison of staging systems

BACKGROUND

The clinical courses of patients with medullary thyroid carcinoma (MTC) vary, and a number of prognostic factors have been studied, but the significance of some of these factors remains controversial.

METHODS

The study group consisted of 104 patients with MTC or C-cell hyperplasia managed at the hospitals of the University of California, San Francisco, between January 1960 and December 1998. Patients were classified as having sporadic MTC, familial non-multiple endocrine neoplasia (MEN) MTC, MEN 2A, or MEN 2B. The TNM, European Organization for Research and Treatment of Cancer (EORTC), National Thyroid Cancer Treatment Cooperative Study (NTCTCS), and Surveillance, Epidemiology, and End Results (SEER) extent-of-disease stages were determined for each patient. The predictive values of these staging or prognostic scoring systems were compared by calculating the proportion of variance explained (PVE) for each system.

RESULTS

Fifty-six percent of the patients had sporadic MTC, 22% had familial MTC, 15% had MEN 2A, and 7% had MEN 2B. The overall average age at diagnosis was 38 years, and patients with sporadic MTC presented at an older age (P < 0.05). Thirty-two percent of the patients with hereditary MTC were diagnosed by screening (genetic and/or biochemical). These patients had a lower incidence of cervical lymph node metastasis (P < 0.05) and 94.7% were cured at last follow-up (P < 0.0001) compared with patients not screened. Patients with sporadic MTC who had systemic symptoms (diarrhea, bone pain, or flushing) had widely metastatic MTC and 33.3% of those patients died within 5 years. Overall, 49.4% of the patients were cured, 12.3% had recurrent MTC, and 38.3% had persistent MTC. The mean follow-up time was 8.6 years (median, 5.0 years) with 10.7% (n=11) and 13.5% (n=14) cause specific mortality at 5 and 10 years, respectively. Patients with persistent or recurrent MTC who died of MTC lived for an average of 3.6 years (ranging from 1 month to 23.7 years). Patients who had total or subtotal thyroidectomy were less likely to have persistent or recurrent MTC (P < 0.05), and patients who had total thyroidectomy with cervical lymph node clearance required fewer reoperations for persistent or recurrent MTC (P < 0.05) than patients who underwent lesser procedures. In univariate analysis, age, gender, clinical presentation, TNM stage, sporadic/hereditary MTC, distant metastasis, and extent of thyroidectomy were significant prognostic factors. Only age and stage, however, remained independent prognostic factors in multivariate analysis. The TNM, EORTC, NTCTCS, and SEER staging systems were all accurate predictors of survival, but the EORTC prognostic scoring system had the highest PVE in this cohort.

CONCLUSIONS

Screening for MTC and early treatment (total thyroidectomy with central neck lymph node clearance) had nearly a 100% cure rate. Patients with postoperative hypercalcitoninemia without clinical or radiologic evidence of residual tumor after apparently curative surgery may enjoy long term survival but have occult MTC. Only patient age at presentation and TNM stage were independent predictors of survival. The EORTC criteria, which included the greatest number of significant prognostic factors in our cohort, had the highest predictive value.

The importance of molecular biology to cancer surgery

Over the last two decades there have been striking advances in molecular biology, which now have, and will continue to have, great impact on the diagnosis and treatment of patients with either benign or malignant diseases. The translation of these new findings from the laboratory to the clinic has just begun and promises to revolutionize the care of patients with certain neoplastic diseases. The most significant advances relate to molecular genetics, particularly the identification of inherited germline mutations that can be identified in kindred members by direct DNA testing. The surgical oncologist is in a pivotal position to define prophylactic interventional strategies for patients who are destined to develop certain solid tumor malignancies. The most immediate opportunities will be in the patients with hereditary disorders, such as breast cancer, large bowel cancer, and the endocrine neoplasia syndromes.

Paraganglioma as a systemic syndrome: pitfalls and strategies

Tumours of the neuroendocrine system in the head and neck region are mostly paragangliomas of the glomus tympanicum or jugulare, or of the carotid body. The majority of these tumours are benign, and the coexistence of multiple paragangliomas seems to be rare. Pre-operative embolization and surgery are regarded as primary therapy for these tumours. The treatment regimen in any patient depends on age, general health, hearing status and the function of the lower cranial nerves. Several presentations are possible in which paragangliomas occur as systemic disease. 1. Paragangliomas may occur bilaterally, or, in rare cases, in multiple areas. Pre-operative bilateral angiography is of utmost importance. In case of multicentricity, it might be necessary to proceed without, or just with, unilateral surgery for preservation of adjacent structures. In surgery of jugular vein paraganglioma, we usually perform a modified transmastoidal and transcervical approach with preservation of middle-ear structures and the ossicles. As an alternative or supplement to surgery, radiotherapy or definitive embolization may be used in the treatment of paragangliomas. 2. Paragangliomas may occur as multiple endocrine neoplasia (MEN) syndrome combined with medullary thyroid gland carcinoma, and, facultatively, pheochromocytoma. In these cases, endocrinological examination and magnetic resonance imaging (MRI) of the adrenal region, the thorax and the neck are required for an adequate therapeutic strategy. As MEN may be inherited, family history should be evaluated. 3. Paragangliomas can became malignant and metastasize. Thus, cervical lymph node metastases or distant metastases may occur. We recommend the removal of all ipsilateral lymph nodes and their histological examination.

Importance-satisfaction discrepancies are associated with health-related quality of life in five-year survivors of endocrine gastrointestinal tumours

BACKGROUND

Little is known about the health-related-quality of life (HRQoL) of patients with endocrine gastrointestinal tumours. In this study, HRQoL was investigated in long-term survivors of endocrine GI tumours.

PATIENTS AND METHODS

A questionnaire including the EORTC QLQ-C30 and ratings of importance of and satisfaction with a variety of HRQoL aspects was mailed to patients with carcinoid tumours (n = 64), or endocrine pancreatic tumours (EPT, n = 55). Median time since diagnosis was 120 months (range 60-360). The majority of patients (77 of 119) had ongoing treatment.

RESULTS

The EORTC QLQ-C30 ratings suggest that in spite of a long disease duration and treatment, patients perceived their HRQoL as relatively good. There were no major differences in HRQoL ratings between patients with carcinoid tumours and those with EPT. Patients whose ratings of importance was higher than their ratings of satisfaction with a specific HRQoL aspect also evidenced a low HRQoL for that aspect.

CONCLUSIONS

The results indicate that survivors of endocrine GI tumours enjoy a relatively good HRQoL and suggest that importance > satisfaction discrepancies identify patients with a low quality of life.

A 50 year perspective on endocrine neoplasia: clinic to genes and back

Having completed medical school and internship in 1947 when effective therapeutic interventions were quite limited (mostly to surgery), I became impressed with the importance of diagnosing the then known treatable diseases. As a young army medical officer, I was exposed to those who emphasized pheochromocytomas and parathyroid adenomas as treatable conditions. After completing internal medicine training, I continued my search for these conditions but it was not until 1958 that I first encountered my first patient with hyperparathyroidism (HPT) who happened to be in a family with many others affected. After leaving the small clinic in Indiana where I practiced for 19 years, in 1970 I came to Henry Ford Hospital where I continued my search for hereditary HPT and encountered families of MEN-2 by applying calcitonin studies to the families of our cases of medullary thyroid cancer. Early genetic linkage studies suggested that progress in the field would benefit from a workshop on MEN-2 and Nancy Simpson agreed to host the first workshop in Kingston in 1984. This and the five subsequent workshops brought together those interested in the field and resulted in the remarkable advances being made in the diagnosis and treatment of endocrine neoplasias and in the understanding of these conditions and of neoplasia in general.

Multiple endocrine neoplasias in a dog: corticotrophic tumour, bilateral adrenocortical tumours, and pheochromocytoma

In a 10-year-old ovariohysterectomized standard Schnauzer, the finding of dexamethasone-resistant hypersecretion of cortisol, the results of computed tomography, and elevated plasma concentrations of ACTH suggested the presence of both adrenocortical tumour and pituitary-dependent hyperadrenocorticism. The dog made an uneventful recovery after bilateral adrenalectomy and remained in good health for 31/2 years with substitution for the induced hypoadrenocorticism. Then the enlarged pituitary caused neurological signs and eventually euthanasia was performed. The surgically excised right adrenal contained a well-circumscribed tumour of differentiated adrenocortical tissue and in the left adrenal there were two adrenocortical tumours and a pheochromocytoma. The unaffected parts of the adrenal cortices were well developed and without regressive transformation. At necropsy there were no metastatic lesions. The cells of the pituitary tumour were immunopositive for ACTH and had characteristics of malignancy. The present combination of corticotrophic tumour, adrenocortical tumours, and pheochromocytoma may be called 'multiple endocrine neoplasia' (MEN), but does not correspond to the inherited combinations of diseases known in humans as the MEN-1 and the MEN-2 syndromes. It is suggested that the co-existence of hyperadrenocorticism and pheochromocytoma may be related to the vascular supply of the adrenals. Some chromaffin cells of the adrenal medulla are directly exposed to cortical venous blood, and intra-adrenal cortisol is known to stimulate catecholamine synthesis and may promote adrenal medullary hyperplasia or neoplasia.

Clinical and molecular aspects of multiple endocrine neoplasia

The discovery that RET proto-oncogene mutations are responsible for MEN2 and FMTC was a landmark from the perspective of many, including the geneticist involved in basic science, the molecular diagnostician, the clinician, and MEN2/FMTC families. The discovery has provided basic information concerning the role of proto-oncogenes and proto-oncogene activation. The identification of MEN2/FMTC-associated mutations has also allowed for the availability of direct mutation analysis in the routine clinical laboratory. The discovery has resulted in definitive risk assessment for members of FMTC/MEN2 kindreds and improved management of RET mutation carriers. The discovery also links two realms of genetics that are often separated: cancer genetics and "classic" mendelian disorders. Finally, information concerning the molecular basis of Hirschsprung disease indicates that our understanding of the phenotypic consequences of RET mutations is considerable but not yet complete.

Parathyroid glands and the multiple endocrine neoplasia syndromes and familial hypocalciuric hypercalcemia

Hypercalcemia is a variable feature of inherited endocrine disorders. In the multiple endocrine neoplasia (MEN) syndromes, generalized hyperparathyroidism is a common feature. It occurs much more frequently in patients with MEN type 1 as compared to patients with MEN type 2A. Unlike the MEN syndromes, patients with familial hypocalciuric hypercalcemia (FHH) have only hypercalcemia with no associated endocrinopathies. The hyperparathyroidism in patients with either of the MEN syndromes is managed by parathyroidectomy, whereas patients with FHH are managed nonoperatively. The specific genetic defects associated with MEN type 2 syndromes and FHH have been identified. They explain, in part, the clinical and pathophysiologic features of these diseases. The genetic defect causative of MEN type 1 will doubtless soon be found and thereby provide further insights into the molecular basis of calcium homeostasis. We will review the clinical presentation and the management of patients with these disorders. We will also review the recent molecular discoveries in MEN 2A, MEN 2B, and FHH, and define how they have altered the management of patients who have these syndromes.

Recent advances in multiple endocrine neoplasia syndromes

The MEN syndrome are autosomal-dominant disorders of endocrine tissues, characterized by tumor development and in many instances, hormonal hypersecretory states. The genetic lesion in MEN I appears to involve a tumor suppressor locus on the long arm of chromosomes 11 but the identity of the affected gene and its role in contributing to dysregulation of endocrine cell function remain unknown. The lesion in MEN II has been localized to the RET protooncogene locus in the pericentromeric region of chromosome 10. This putative single transmembrane-domain, tyrosine kinase-linked receptor is selectively mutated to produce a constitutively activated protein and presumably an undampened growth-promoting signal to the target cell. Additional studies focused on these genes and their products should facilitate the screening and treatment of patients affected with these disorders and, potentially, provide more information about the role that these genes play in the normal growth and development of endocrine tissues. Such information should prove valuable in deciphering the pathogenetic mechanisms underlying the development of the more common sporadic endocrine tumors.

Diagnosis and management of adrenal tumors

Tumors of the adrenal gland are not uncommon. Patients with these tumors usually demonstrate symptoms associated with the biochemical substance or hormone produced by the tumor. Tumors of the adrenal cortex, whether benign or malignant, are often associated with excess production of steroids, whereas tumors of the medulla are generally associated with overproduction of catecholamines. With the ubiquitous use of computed tomographic imaging, many asymptomatic adrenal lesions are discovered, presenting a management problem for the clinician. The algorithm for investigating so-called adrenal "incidentalomas" in the current era of cost containment continues to evolve. This review addresses current trends in the clinical evaluation, biochemical testing, and nuclear and radiologic imaging in the diagnostic work-up of these neoplasms. The mainstay of treatment is still surgical extirpation, the only curative modality. However, advances have occurred in adjuvant therapies, perhaps best typified by the neoadjuvant use of 131I-methyl iodobenzylguanidine in the treatment of neuroblastoma.