Recent advances in systemic therapy for gastrointestinal neuroendocrine tumors

Efficacy of adding high-dose In-111 octreotide therapy during Sandostatin treatment in patients with disseminated neuroendocrine tumors: clinical results of 14 patients

PURPOSE

This study aimed to assess the outcome of high-dose In-111 octreotide treatment and efficacy of long-acting Sandostatin LAR in patients with disseminated neuroendocrine tumors.

MATERIALS AND METHODS

A total of 14 patients (mean age 51.8 ± 13.2 years; 10 female, 4 male) receiving high-dose In-111 octreotide in our centre for the treatment of neuroendocrine tumors were included in the study. Monthly treatment with long-acting somatostatin analogue [Sandostatin long-acting release (Novartis Pharmaceuticals)] was continued in nine cases.

RESULTS

During a 3-year period, a total of 45 courses of high-dose In-111 octreotide treatment were delivered to 14 patients. In seven patients receiving an average of four treatment courses (6 carcinoid tumors, 1 thymoma, patients: 2, 4, 5, 11-14) stable disease was achieved (50%). In two patients with carcinoid tumors (patients 1 and 3) who received four treatment courses, partial response was observed (14%). Five patients (36%; 4 NET, 1 gastrinoma; patients 6-10) died due to progressive disease following on average two treatment courses. On average, deaths occurred 2 months after the last treatment dose. No complete responses were seen. Partial response was achieved in two of the nine patients receiving Sandostatin LAR, while four had stable disease. Both treatments were associated with acceptable tolerability.

CONCLUSIONS

High-dose In-111 octreotide can be safely administered in conjunction with somatostatin analogue in patients with disseminated NET and this treatment may help to stabilize the disease.

Neuroendocrine tumors of the pancreas

Pancreatic endocrine tumors are rare neoplasms accounting for less than 5% of pancreatic malignancies. They are broadly classified into either functioning tumors (insulinomas, gastrinomas, glucagonomas, VIPomas, and somatostatinomas) or nonfunctioning tumors. The diagnosis of these tumors is difficult and requires a careful history and examination combined with laboratory tests and radiologic imaging. Signs and symptoms are usually related to hormone hypersecretion in the case of functioning tumors and to tumor size or metastases with nonfunctioning tumors. Surgical resection remains the treatment of choice even in the face of metastatic disease. Further development of novel diagnostic and treatment modalities offers potential to greatly improve quality of life and prolong disease-free survival for patients with pancreatic endocrine tumors.

Tumor carcinóide de reto

OBJETIVO: estudar o tratamento e a evolução de 7 casos de tumor carcinóide de reto. PACIENTES E MÉTODO: análise retrospectiva do prontuário de 7 pacientes atendidos no Hospital Geral de Goiânia e Instituto de Coloproctologia de Goiânia. RESULTADOS: 7 casos de tumor carcinóide de reto foram diagnosticados incidentalmente durante colonoscopias realizadas por indicações diversas. Em todos os casos foram realizadas polipectomias endoscópicas. Análises histológicas e imunohistoquímicas evidenciaram tumor carcinóide em todos os casos. Realizada retossigmoidectomia anterior em dois casos, devido a comprometimento da camada muscular da mucosa e excisão local transanal em um caso, devido a evidência de neoplasia atípica. O seguimento médio foi de 28 meses com evolução satisfatória em todos os casos. CONCLUSÃO: Os 7 pacientes com tumor carcinóide de reto estudados foram inicialmente tratados com ressecção endoscópica, tendo evolução satisfatória e mantendo-se livres de doença no período de seguimento.

Endocrine tumours of the gastrointestinal tract. Management of metastatic endocrine tumours

Gastroenteropancreatic tumours are rare. They compromise a heterogenous class of neoplasm. If there is no hypersecretion syndrome, symptoms may be uncharacteristic and thus diagnosis occurs rather late after the first manifestations of the disease. The most important prognostic parameters are histological classification, the localisation of the primary, the tumour size and stage at diagnosis, and the presence or absence of metachronous or synchronous neoplasia. The article will focus on the importance of each of these parameters for the various treatment options in patients with metastatic disease.

Enteroendocrine tumors other than carcinoid: a review of clinically significant advances

Only relatively recently has there been an increased clinical recognition and characterization of the heterogeneous group of rare gastroenteropancreatic neuroendocrine neoplasms. Most have endocrine function and exhibit varying degrees of malignancy. This review summarizes the derivation of these tumors and the advances in their diagnosis and treatment over the past decade and a half. They are varied in their biological behavior and clinical courses and, depending on their cell type, can produce different hormones causing distinct clinical endocrine syndromes (insulinoma [hypoglycemia], gastrinoma [Zollinger-Ellison syndrome (ZES)], vasoactive intestinal peptideoma [VIPoma], watery diarrhea, hypokalemia-achlorhydria [WDHA], glucagonoma [glucagonoma syndrome], and so forth). In addition to surgery for cure or palliation (by excision and a variety of other cytoreductive techniques), they each are treated with anti-hormonal agents or drugs targeted to each tumor's specific product or its effects. The majority have benefited from the gut hormone-inhibiting action of somatostatin analogs. Because of their usual slow rate of growth it is recommended that, even when they are advanced and incurable, unlike in patients with common and more malignant cancers, patients with neuroendocrine tumors often can be palliated and appear to survive longer when managed with an active approach using sequential multimodality treatment. Advances in these various therapies are reviewed and the beneficial emergence of global self-help patient support groups is noted.

Survival and clinical outcome of patients with neuroendocrine tumors of the gastroenteropancreatic tract in a german referral center

Neuroendocrine tumors (NETs) are rare neoplasms. Approximately 75% of all cases manifest in the gastroenteropancreatic (GEP) system. Because of the low incidence of NETs, limited data about the clinical outcome and prognostic variables are available. In an attempt to identify prognostic parameters, we investigated the distribution of primary tumors, pattern of metastasis formation, clinical presentation, histological classification, and outcome of therapeutic interventions in a large patient cohort cared for in a German referral center. In 254 patients with GEP-NETs, the primary tumor was of foregut, midgut, or hindgut origin in 44.1% (28.7% pancreas), 43.7% (34.7% jejunoileum), and 4.3%, respectively. No primary tumor was found in 7.9%. Metastases occurred preferentially in lymph nodes and the liver. The overall 5-year survival rate was 57.1%. In the absence or presence of metastases at initial diagnosis the 5-year survival rate was 80.0% and 51.7%, respectively. The 5-year survival rate was related to the localization of the primary and was 75.0% and 42.9% for jejunoileal and pancreatic tumors, respectively. The size of the primary tumor (<2 cm) and histological grading as low-grade malignant were both associated with a significantly longer survival. Surgery with curative intent was attempted in 141 patients. However, an R(0) resection was achieved in only 66.0% of these patients. Five-year survival rate in the latter group was significantly higher (77.3%) as compared with all surgical patients (55.4%). Long-term tumor-free survival was obtained in only 53.7% of successfully resected patients. Palliative medical treatment, either with chemotherapy (i.e., especially for foregut NETs) or biotherapy (especially for midgut NETs), was only moderately effective for both therapeutic regimens.

The diagnosis and medical management of advanced neuroendocrine tumors

Neuroendocrine tumors (NETs) constitute a heterogeneous group of neoplasms that originate from endocrine glands such as the pituitary, the parathyroids, and the (neuroendocrine) adrenal, as well as endocrine islets within glandular tissue (thyroid or pancreatic) and cells dispersed between exocrine cells, such as endocrine cells of the digestive (gastroenteropancreatic) and respiratory tracts. Conventionally, NETs may present with a wide variety of functional or nonfunctional endocrine syndromes and may be familial and have other associated tumors. Assessment of specific or general tumor markers offers high sensitivity in establishing the diagnosis and can also have prognostic significance. Imaging modalities include endoscopic ultrasonography, computed tomography and magnetic resonance imaging, and particularly, scintigraphy with somatostatin analogs and metaiodobenzylguanidine. Successful treatment of disseminated NETs requires a multimodal approach; radical tumor surgery may be curative but is rarely possible. Well-differentiated and slow-growing gastroenteropancreatic tumors should be treated with somatostatin analogs or alpha-interferon, with chemotherapy being reserved for poorly differentiated and progressive tumors. Therapy with radionuclides may be used for tumors exhibiting uptake to a diagnostic scan, either after surgery to eradicate microscopic residual disease or later if conventional treatment or biotherapy fails. Maintenance of the quality of life should be a priority, particularly because patients with disseminated disease may experience prolonged survival.

Nonsteroidal anti-inflammatory drugs inhibit growth of human neuroendocrine tumor cells via G1 cell-cycle arrest

Therapeutic options to inhibit growth of human NETs of the GEP system are limited. Since NSAIDs might provide an antiproliferative treatment alternative with acceptable toxicity, we examined the effects of different NSAIDs on growth and survival in a representative set of human GEP NET cell lines. Growth and apoptosis were determined based on cell numbers, cell-cycle analyses, kinase assays, DNA fragmentation and PARP cleavage. Expression of COX and cell cycle-regulatory molecules was examined by immunoblotting and reporter gene assays. Depending on the drug and cell line investigated, NSAID treatment resulted in profound growth inhibition of GEP NET cells. Growth-inhibitory effects were achieved with either COX-2 selective (NS398) or unselective (indomethacin, sulindac) compounds. Cell-cycle analyses documented a G1 arrest in NSAID-treated GEP NET populations. In addition, 100 microM sulindac or indomethacin induced apoptosis. All 3 COX inhibitors prevented CDK-2 activation. In parallel to the NSAID-mediated reduction of CDK-2 activity, p21(cip-1) promoter activity and cellular p21(cip-1) levels increased and p21(cip-1) was sequestered into CDK-2 complexes. Thus, the G1 arrest likely resulted from p21(cip-1)-dependent inhibition of CDK-2 activity. At therapeutically relevant concentrations, sulindac significantly reduced GEP NET cell numbers, whereas IFN-alpha and octreotide remained ineffective. The extent of growth inhibition in GEP NETs was comparable to the antiproliferative effects of sulindac in established NSAID-sensitive cell models. NSAIDs acted as potent antiproliferative agents in GEP NET cells via G1 cell-cycle arrest and might therefore offer a therapeutic alternative to current treatment modalities.

Basis for treatment of functioning neuroendocrine tumours

A general characteristic of GEP endocrine tumours is that vast majority produce and secrete a multitude of peptide hormones and amines. The rarity of these types of tumours, their possible episodic expression and the variable clinical symptoms, are the reasons why patients are often diagnosed late in the advanced stages of the disease. For these reasons, the patients with advanced metastatic disease should be treated aggressively with medical and surgical therapies aimed at reducing both symptoms and complications through strategies that reduce tumour bulk and block hormonal effects. The medical treatment of functioning endocrine tumours of the gastrointestinal tract must be based on the growth properties of the tumour and includes chemotherapy, somatostatin analogs, alpha-interferon alone and associated with somatostatin analogs, chemoembolization and radiolabelled somatostatin analogs. Even if chemotherapy has been basis of therapy for these types of tumours for a long time, it is currently reserved for progressive disease and anaplastic tumours. Biotherapy, with interferon and somatostatin analogs has been demonstrated to have a significant antitumor effect and causes an improvement of symptoms in patients with functioning neuroendocrine tumours. Furthermore, these drugs produce a notable improvement in the quality of life. Radioactive targeting therapy is the most promising new treatment modality for patients who have SST receptor positive tumours.

Efficacy of a chemotherapy combination for the treatment of metastatic neuroendocrine tumours

OBJECTIVES

Neuroendocrine tumours (NETs) are heterogeneous neoplasms for which there is no standard treatment. We have previously proposed an effective polychemotherapy (5-fluorouracil, dacarbazine and epirubicin), which only produced objective responses of brief duration. The present study aimed to assess in a multidisciplinary manner the efficacy of the same regimen at intensified doses in patients with advanced NETs.

PATIENTS AND METHODS

Eighty-two consecutive patients entered the study, of whom 21 had inoperable, locally advanced disease and 61 had metastatic disease. Seventy-two patients were evaluated for objective, biochemical and subjective responses. Response rate, time to progression (TTP) and overall survival (OS) were evaluated based on histotype.

RESULTS

An objective response was observed in 20 patients (intention-to-treat and standard analysis 24.4% and 27.8%, respectively). Complete biochemical and subjective responses were obtained in 25.1% and 38.9% of the cases. The median duration of treatment was 4 months and the objective responses had a median duration of 38 months. After a 60-month follow-up the median TTP and OS were 21 and 38 months, respectively.

CONCLUSIONS

Our polychemotherapy regimen is effective, with long duration, and is well tolerated both for gastroenteropancreatic and lung NETs, as well as for tumours with a more aggressive clinical behaviour. The new WHO endocrine tumour histotyping, examining also the tumour biology, may give additional information for selecting patients to chemotherapy.

Prospective study of the natural history of gastrinoma in patients with MEN1: definition of an aggressive and a nonaggressive form

The natural history of pancreatic endocrine tumors (PETs) in patients with MEN1 is largely unknown. Recent studies in patients with sporadic PETs show that in a subset, tumor growth is aggressive. To determine whether PETs in patients with MEN1 show similar growth behavior, we report results from a long-term prospective study of 57 patients with MEN1 and Zollinger-Ellison syndrome. All patients had tumor imaging studies yearly, and the mean follow-up was 8 yr. Only patients with PETs 2.5 cm or larger underwent abdominal surgical exploration. Hepatic metastases occurred in 23%, and in 14% tumors demonstrated aggressive growth. Three tumor-related deaths occurred, each due to liver metastases, and in each, aggressive tumor growth was present. Overall, 4% of the study group, 23% with liver metastases and 38% with aggressive disease, died. Aggressive growth was associated with higher gastrins and larger tumors. Patients with liver metastases with aggressive growth differed from those with liver metastases without aggressive growth in age at MEN1 onset or diagnosis and primary tumor size. Survival was decreased (P = 0.0012) in patients with aggressive tumor growth compared with those with liver metastases without aggressive growth or with no liver metastases without aggressive growth. Based on these results a number of factors were identified that may be clinically useful in determining in which patients aggressive tumor growth may occur. These results demonstrate in a significant subset of patients with MEN1 and Zollinger-Ellison syndrome, aggressive tumor growth occurs and can lead to decreased survival. The identification of prognostic factors that identify this group will be important clinically in allowing more aggressive treatment options to be instituted earlier.

Carcinoid and pancreatic endocrine tumors: recent advances in molecular pathogenesis, localization, and treatment

Neuroendocrine tumors include carcinoids and pancreatic endocrine tumors, which share a number of common features in their pathology, ability to cause clinical symptoms due to ectopic hormone and bioamine release, localization methods, and treatment. Although generally slow growing, a proportion demonstrate aggressive tumor growth. Therefore, in many cases treatment must be directed against both the tumor and the hormone-excess state. There have been significant recent advances into their molecular pathogenesis, natural history, and prognostic factors; clinical presentation defined by larger series analysis; localization methods; and the development of new treatments directed against the tumor and to control the hormone-excess state (including depot somatostatin analogues, interferon combinations, embolization, chemoembolization, radiotherapy with novel somatostatin analogues, and liver transplantation). Recent advances in each of these areas are briefly discussed.