Multiple endocrine neoplasia type I. Surgical therapy

Gastroenteropancreatic neuroendocrine tumors in multiple endocrine neoplasia type 1

We reviewed the literature about entero-pancreatic neuroendocrine tumors in Multiple Endocrine Neoplasia type 1 syndrome (MEN1) to clarify their demographic features, localization imaging, practice, and appropriate therapeutical strategies, analyzing the current approach to entero-pancreatic neuroendocrine tumors in MEN1. Despite the fact that hyperparathyroidism is usually the first manifestation of MEN1, the penetrance of these tumors is similar. They are characterized by multiplicity of lesions, variable expression of the tumors, and propensity for malignant degeneration. Both the histological type and the size of MEN1 neuroendocrine tumors correlate with malignancy. Monitoring of pancreatic peptides and use of imaging exams allow early diagnosis and prompt surgical treatment, resulting in prevention of metastatic disease and improvement of long-term survival. Surgery is often the treatment of choice for MEN1-neuroendocrine tumors. The rationale for surgical approach is to curtail malignant progression of the disease, and to cure the associated biochemical syndrome, should it be present.

Pancreatic endocrine tumors in multiple endocrine neoplasia type 1 syndrome: review of literature

OBJECTIVE

To analyze the surgical approach to multiple endocrine neoplasia type 1 (MEN 1)-related pancreatic endocrine tumors (PETs).

METHODS

We reviewed selected publications and our personal experience with MEN 1-associated PETs to delineate their general characteristics, current practice and controversies, preoperative imaging and intraoperative assessment, and appropriate therapeutic strategies including radical surgical procedures.

RESULTS

The penetrance of PETs in the setting of MEN 1 is similar to that of parathyroid tumors, even though hyperparathyroidism is usually the first manifestation of MEN 1 syndrome. In contrast with the sporadic counterparts, MEN 1-related PETs are characterized by an early onset, multiplicity of lesions, variable expression of the tumors, and propensity for malignant degeneration. Both the histologic type and the size of these tumors correlate with malignant potential.

CONCLUSION

The rationale for surgical considerations for these tumors is to curtail the malignant progression of the disease and to cure or aid in management of the associated biochemical syndromes. A surgical procedure is often the treatment of choice for PETs in patients with MEN 1. Monitoring of pancreatic peptides and use of diagnostic imaging allow an early pancreatic resection, in conjunction with prevention of metastatic PETs and improvement of long-term survival. Hepatic metastatic lesions can be successfully treated by surgical resection.

Achieving eugastrinemia in MEN1 patients: both duodenal inspection and formal lymph node dissection are important

BACKGROUND

Controversy exists regarding the role and extent of operation for patients with multiple endocrine neoplasia type 1 (MEN1) and hypergastrinemia.

METHODS

An institutional MEN1 database was reviewed to identify patients with evidence of hypergastrinemia. The relationship of extent of resection to achievement of eugastrinemia was evaluated.

RESULTS

Operation was performed in 20 patients with MEN1 and hypergastrinemia with a median follow-up of 71 months. Duodenal gastrinomas were identified in 85% of patients who underwent duodenal evaluation. Nodal metastases were identified in 80%. Patients who underwent anatomic regional lymph node dissection (RLND) had a median of 16 nodes removed, vs 1 in patients who did not undergo a formal regional lymphadenectomy. Eugastrinemia was achieved in 12 patients (60%), and 8 (40%) had persistent hypergastrinemia. Compared with patients with persistent hypergastrinemia, patients rendered eugastrinemic more often underwent duodenal evaluation (11/12 vs 2/8; P = .01) and RLND (11/12 vs 3/8; P = .03); there was no relationship between pancreatic resection and achievement of eugastrinemia (P = .32).

CONCLUSION

For patients with MEN1-associated hypergastrinemia selected for operative treatment, a strategy including duodenal evaluation and anatomic regional lymphadenectomy is associated with long-term eugastrinemia. In contrast, the extent of pancreatic resection should be dictated by the extent and distribution of pancreatic neuroendocrine neoplasms, rather than by the presence of hypergastrinemia.

Inherited pancreatic endocrine tumor syndromes: advances in molecular pathogenesis, diagnosis, management, and controversies

Pancreatic endocrine tumors (PETs) can occur as part of 4 inherited disorders, including Multiple Endocrine Neoplasia type 1 (MEN1), von Hippel-Lindau disease (VHL), neurofibromatosis 1 (NF-1) (von Recklinghausen disease), and the tuberous sclerosis complex (TSC). The relative frequency with which patients who have these disorders develop PETs is MEN1>VHL>NF-1>TSC. Over the last few years, there have been major advances in the understanding of the genetics and molecular pathogenesis of these disorders as well in the localization and the medical and surgical treatment of PETs in such patients. The study of PETs in these disorders not only has provided insights into the possible pathogenesis of sporadic PETs but also has presented several unique management and treatment issues, some of which are applicable to patients with sporadic PETs. Therefore, the study of PETs in these uncommon disorders has provided valuable insights that, in many cases, are applicable to the general group of patients with sporadic PETs. In this article, these areas are reviewed briefly along with the current state of knowledge of the PETs in these disorders, and the controversies that exist in their management are summarized briefly and discussed.

Management of pancreatic endocrine tumors in multiple endocrine neoplasia type 1

INTRODUCTION

Pancreatic endocrine tumors (PETs) occur in at least 50% of patients with multiple endocrine neoplasia type 1 (MEN1) and are the leading cause of disease-specific mortality. However, the timing and extent of surgery for MEN1-related PETs is controversial owing to the indolent tumor growth seen in most patients and the desire to avoid complications associated with insulin dependence. To help resolve this controversy, we retrospectively analyzed the clinical characteristics, surgical treatment, and clinical outcome of patients with MEN1-related PETs.

METHODS

All patients had histologic or radiographic confirmation of a PET in the setting of MEN1. Disease progression was defined radiographically as the development of new pancreatic tumors or distant metastases. Progression-free survival (PFS) and overall survival (OS) were used as the endpoints of this analysis.

RESULTS

We identified 98 patients with MEN1, 55 (56%) of whom had PETs, including 27 women and 28 men with a median age of 37 years (range 8-69 years) at the time of diagnosis. Functioning PETs were present in 35 (64%) of 55 patients, and nonfunctioning tumors were present in 20 (36%). Pancreatic surgery was performed in 38 (69%) of the 55 patients; and the first operation included enucleation (n = 4), total pancreatectomy (n = 3), Whipple procedure (n = 4), and distal pancreatectomy (n = 27). The median size of the resected tumors was 2.8 cm (range 0.6-11.0 cm). Recurrent disease developed in the residual pancreas in 7 (20%) of 35 at-risk patients a median of 7.8 years after the first operation, and distant metastases occurred in 5 (14 %) of 36 surgically treated patients without distant metastasis (2 patients had distant metastases when surgery on the primary tumor was performed) at a median of 2.7 years following surgery. At last follow-up, 16 (29%) of 55 patients with PETs had died, 12 (22%) were alive with disease, 26 (47%) were alive without evidence of disease, and 1 (2%) was lost to follow-up. The median OS was 19.5 years (range 13-26 years) and was significantly longer for patients who had functioning PETs versus those with nonfunctioning tumors (P = 0.0007), for patients who underwent surgical resection of their PETs versus those who did not (P = 0.0043), and for patients with localized versus metastatic PETs at the time of diagnosis (P < 0.0001). Multivariate analysis revealed that younger age, hormonal function, and PET resection were independently associated with longer OS.

CONCLUSIONS

Our data suggest that early diagnosis and surgical excision of MEN1-related PETs improves survival. However, translating these data into a surveillance strategy for the early detection of PETs is complex owing to the potential morbidity of pancreatic resection and the risk of long-term insulin dependence.

Surgical treatment of non-functioning pancreatic islet cell tumors

Pancreatic endocrine tumors (PETs) are rare neoplasms originating from the amine precursor uptake and decarboxylation (APUD) stem cells. Although the majority of PETs are sporadic, they frequently occur in familial syndromes. PETs may cause a variety of functional syndromes or symptoms of local progression if they are non-functional. General neuroendocrine tumor markers are highly sensitive in the diagnostic assessment of a PET. Imaging studies for tumor localization and staging include computer tomography (CT) scan, magnetic resonance imaging (MRI), In(111)-octreotide scan, MIBG, and endoscopic ultrasonography (EUS). Treatment of PETs often requires a multi-modality approach; however, surgical resection remains the only curative therapy for localized (non-metastatic) disease. Treatment of metastatic disease includes biologic agents, cytotoxic chemotherapy, and liver-directed therapies.

Calcium agonists in hyperparathyroidism

Primary hyperparathyroidism (PHPT), in addition to cancer, represents an important cause of hypercalcaemia in the general population. Furthermore, hypercalcaemia, in the course of uraemic HPT, represents the late stage of chronic renal failure refractory to therapy. Neck surgery is still the only curative approach for these forms of HPT and medical treatment rarely exhibits an effective control on HPT and HPT-dependent hypercalcaemia. Moreover, some HPT patients may not undergo neck surgery due to the presence of other concomitant disorders. Therefore, more effective therapeutic approaches are needed than the commonly used 'palliative' treatments. The identification of a specific membrane receptor able to bind extracellular calcium on cells of the parathyroid and other tissues has allowed the development of new molecules acting through this receptor to reduce both parathyroid hormone secretion and the rate of parathyroid cell proliferation. Consequently, they may substantially contribute to the regulation of bloodstream calcium levels in HPT patients. Preliminary results obtained in clinical trials are encouraging, demonstrating a good efficacy and safety of such drugs. However, more in vitro and in vivo, as well as long-term clinical studies, will be necessary before they can be commonly used as therapeutical molecules in the clinical practice.

Resolved and unresolved controversies in the surgical management of patients with Zollinger-Ellison syndrome

OBJECTIVE

Highlight unresolved controversies in the management of Zollinger-Ellison syndrome (ZES).

SUMMARY BACKGROUND DATA

Recent studies have resolved some of the previous controversies including the surgical cure rate in patients with and without Multiple Endocrine Neoplasia-type1 (MEN1), the biological behavior of duodenal and pancreatic gastrinomas, role of imaging studies to localize tumor, and gastrectomy to manage acid output.

METHODS

Review of the literature based on computer searches in Index Medicus, Pubmed and Ovid.

RESULTS

Current controversies as identified in the literature include the role of endoscopic ultrasound (EUS), surgery in ZES patients with MEN1, pancreaticoduodenectomy (Whipple procedure), lymph node primary gastrinoma, parietal cell vagotomy, reoperation and surgery for metastatic tumor, and the use of minimally invasive surgical techniques to localize and remove gastrinoma.

CONCLUSIONS

It is hoped that future studies will focus on these issues to improve the surgical management of ZES patients.

Parathyroidectomy in familial hypercalcemia with clinical characteristics of primary hyperparathyroidism and familial hypocalciuric hypercalcemia

BACKGROUND

Familial primary hyperparathyroidism is associated with tumor-susceptibility syndromes, which are unrelated to mutations in the calcium receptor gene. This study describes parathyroidectomy in a kindred with hypercalcemia due to a heterozygous point mutation in the calcium receptor gene.

METHODS

Seventeen family members were studied, and postoperative follow-up averaged 5.1 years.

RESULTS

Radical parathyroid resection with total parathyroid remnants of 10 to 20 mg or total parathyroidectomy with autotransplantation normalized the serum calcium and parathyroid hormone values in 12 family members. Persistent hypercalcemia was noted in 3 of 5 patients subjected to less radical procedures. Diffuse to nodular hyperplasia and microscopic findings, interpreted incorrectly as a single adenoma, were found. Weight of the parathyroid tissue increased with the age of the patients (P <.05), and almost one third of them (29%) had 1 to 3 atypically located glands. There were no patients with recurrent hypercalcemia during follow-up.

CONCLUSIONS

The heterozygous inactivating mutation of the calcium receptor gene of this family is accompanied by mild increases in parathyroid gland x weight and diffuse parathyroid hyperplasia with possibly secondary genetic events causing nodule formation. Radical parathyroid resection is advocated in this hypercalcemic disorder, which may represent an intermediary stage between primary hyperparathyroidism and familial hypocalciuric hypercalcemia.

Comparison of surgical results in patients with advanced and limited disease with multiple endocrine neoplasia type 1 and Zollinger-Ellison syndrome

OBJECTIVE

To determine the role of surgery in patients with Zollinger-Ellison syndrome (ZES) and multiple endocrine neoplasia type 1 (MEN1) with either limited or advanced pancreatic endocrine tumors (PETs).

SUMMARY BACKGROUND DATA

The role of surgery in patients with MEN1 and ZES is controversial. There have been numerous previous studies of surgery in patients with PETs; however, there are no prospective studies on the results of surgery in patients with advanced disease.

METHODS

Eighty-one consecutive patients with MEN1 and ZES were assigned to one of four groups depending on the results of imaging studies. Group 1 (n = 17) (all PETs smaller than 2.5 cm) and group 3 (n = 8) (diffuse liver metastases) did not undergo surgery. All patients in group 2A (n = 17; single PET 2.5-6 cm [limited disease]) and group 2B (n = 31; two or more lesions, 2.5 cm in diameter or larger, or one lesion larger than 6 cm) underwent laparotomy. Tumors were preferably removed by simple enucleation, or if not feasible resection. Patients were reevaluated yearly.

RESULTS

Pancreatic endocrine tumors were found in all patients at surgery, with groups 2A and 2B having 1.7 +/- 0.4 and 4.8 +/- 1 PETs, respectively. Further, 35% of the patients in group 2A and 88% of the patients in group 2B had multiple PETs, 53% and 84% had a pancreatic PET, 53% and 68% had a duodenal gastrinoma, 65% and 71% had lymph node metastases, and 0% and 12% had liver metastases. Of the patients in groups 2A and 2B, 24% and 58% had a distal pancreatectomy, 0% and 13% had a hepatic resection, 0% and 6% had a Whipple operation, and 53% and 68% had a duodenal resection. No patient was cured at 5 years. There were no deaths. The early complication rate, 29%, was similar for groups 2A and 2B. Mean follow-up from surgery was 6.9 +/- 0.8 years, and during follow-up liver metastases developed in 6% of the patients in groups 2A and 2B. Groups 1, 2A, and 2B had similar 15-year survival rates (89-100%); they were significantly better than the survival rate for group 3 (52%).

CONCLUSIONS

Almost 40% of patients with MEN1 and ZES have advanced disease without diffuse distant metastases. Despite multiple primaries and a 70% incidence of lymph node metastases, tumor can be removed with no deaths and complication rates similar to those in patients with limited disease. Further, despite previous studies showing that patients with advanced disease have decreased survival rates, in this study the patients with advanced tumor who underwent surgical resection had the same survival as patients with limited disease and patients without identifiable tumor. This suggests that surgical resection should be performed in patients with MEN1 who have ZES and advanced localized PET.