Recombinant interferon alpha-2b in patients with metastatic apudomas: effect on tumours and tumour markers

Colorectal Cancer Immunotherapy: Options and Strategies

Colorectal cancer is the third most common cancer in the world with increasing incidence and mortality rates globally. Standard treatments for colorectal cancer have always been surgery, chemotherapy and radiotherapy which may be used in combination to treat patients. However, these treatments have many side effects due to their non-specificity and cytotoxicity toward any cells including normal cells that are growing and dividing. Furthermore, many patients succumb to relapse even after a series of treatments. Thus, it is crucial to have more alternative and effective treatments to treat CRC patients. Immunotherapy is one of the new alternatives in cancer treatment. The strategy is to utilize patients' own immune systems in combating the cancer cells. Cancer immunotherapy overcomes the issue of specificity which is the major problem in chemotherapy and radiotherapy. The normal cells with no cancer antigens are not affected. The outcomes of some cancer immunotherapy have been astonishing in some cases, but some which rely on the status of patients' own immune systems are not. Those patients who responded well to cancer immunotherapy have a better prognostic and better quality of life.

Management of Small Bowel Neuroendocrine Tumors

Several important landmark trials have reshaped the landscape of non-surgical management of small bowel neuroendocrine tumors over the last few years, with the confirmation of the antitumor effect of somatostatin analogue therapy in PROMID and CLARINET trials as well as the advent of therapies with significant potential such as mammalian target of rapamycin inhibitor (mTor) everolimus (RADIANT trials) and peptide receptor radionuclide therapy (PRRT) with 177-Lutetium (NETTER-1 trial). This narrative summarizes the recommended management strategies of small bowel neuroendocrine tumors. We review the main evidence behind each recommendation as well as compare and contrast four major guidelines, namely the 2016 Canadian Consensus guidelines, the 2017 North American Neuroendocrine Tumor Society guidelines, the 2018 National Comprehensive Cancer Network guidelines, and the 2016 European Neuroendocrine Tumor Society guidelines. Different clinical situations will be addressed, from loco-regional therapy to metastatic unresectable disease. Carcinoid syndrome, which is mostly managed by somatostatin analogue therapy and the serotonin antagonist telotristat etiprate for refractory diarrhea, as well as neuroendocrine carcinoma will be reviewed. However, several questions remain unanswered, such as the optimal management of neuroendocrine carcinomas or the effect of combining and sequencing of the aforementioned modalities where more randomized controlled trials are needed.

Medical Treatment of Neuroendocrine Tumors

Background

Tumors of the neuroendocrine system are characterized by amine precursor uptake and decarboxylation, and they represent a heterogeneous group of carcinomas including carcinoids, islet cell carcinomas of the pancreas, medullary thyroid carcinomas and Merkel cell carcinomas. Their similar cytochemical and ultrastructural properties sustain the hypothesis of a common embryologic origin within the neural crest. Many of these tumors grow slowly, and reducing tumor burden represents the treatment of choice. However, when surgery is not feasible, medical treatment has to be considered. Therapeutic approaches in metastatic disease often do not consider the different biologic behaviors of these neoplasms. Moreover, efficacy of the treatment is associated with lack of a clear definition of the type of response: objective, symptomatic or biochemical.

Methods

In this review we have analyzed the different medical approaches used in the treatment of neuroendocrine tumors in an attempt to define their precise role in the different neoplasms.

Results

In carcinoid tumors, immunotherapy and the somatostatin analogue can be efficaciously used for the control of carcinoid syndrome. For inhibition of tumor growth, chemotherapy should be used only in patients with rapidly progressive disease, and the results are still unsatisfactory.

Conclusions

Although all these tumors appear to have similar cytochemical properties, the responsiveness of the various neoplasms is very different. In the future, a specific treatment modality and a clear definition of the type of response (objective, symptomatic or biochemical) need to be defined for each type of neuroendocrine tumor.

Nothing But NET: A Review of Neuroendocrine Tumors and Carcinomas

This review covers the diverse topic of neuroendocrine neoplasms (NENs), a relatively rare and heterogeneous tumor type, comprising ~2% of all malignancies, with a prevalence of <200,000 in the United States, which makes it an orphan disease (Basu et al., 2010).1 For functional purposes, NENs are divided into two groups on the basis of clinical behavior, histology, and proliferation rate: well differentiated (low grade to intermediate grade) neuroendocrine tumors and poorly differentiated (high grade) neuroendocrine carcinoma (Bosman et al., 2010)2; this histological categorization/dichotomization is highly clinically relevant with respect to impact on treatment and prognosis even though it is not absolute since a subset of tumors with a low-grade appearance behaves similarly to high-grade lesions. Given the relative dearth of evidenced-based literature about this orphan disease as a whole (Modlin et al., 2008),3 since the focus of most articles is on particular anatomic subtypes of NENs (i.e., gastroenteropancreatic or pulmonary), the purpose of this review is to summarize the presentation, pathophysiology, staging, current standard of care treatments, and active areas of current research.

New therapeutic approaches to metastatic gastroenteropancreatic neuroendocrine tumors: A glimpse into the future

Neuroendocrine (NE) gastroenteropancreatic tumors are a heterogeneous group of neoplasias arising from neuroendocrine cells of the embryological gut. Their incidence have increased significantly over the past 3 decades probably due to the improvements in imaging and diagnosis. The recent advances in molecular biology have translated into an expansion of therapeutic approaches to these patients. Somatostatin analogs, which initially were approved for control of hormonal syndromes, have recently been proven to inhibit tumor growth. Several new drugs such as antiangiogenics and others targeting mammalian target of rapamycin pathways have been approved to treat progressive pancreatic neuroendocrine tumors (NETs) although their role in non-pancreatic is still controversial. The treatment of NETs requires a coordinated multidisciplinary approach. The management of localized NETs primarily involves surgical resection followed by surveillance. However, the treatment of unresectable and/or metastatic disease may involve a combination of surgical resection, systemic therapy, and liver-directed therapies with the goal of alleviating symptoms of peptide release and controlling tumor growth. This article will review the current therapeutic strategies for metastatic gastroenteropancreatic NETs and will take a glimpse into the future approaches.

Biotherapies for GEP-NETs

Biological treatment for GI neuroendocrine tumours (NETs) includes treatment with somatostatin analogues and alpha interferons. Both of these therapies were developed in the early 1980's and initially for treatment of a carcinoid syndrome in patients with small intestinal NETs. Later on tumour biology studies indicated that well differentiated NETs (G1-tumours) benefit from treatment with somatostatin analogues and alpha interferons. Both agents give symptomatic improvement in patients with functioning tumours in 40-60% of the patients, biochemical responses in 50-70% of the patients and significant tumour shrinkage in 5-10% of the patients. Combination therapy with somatostatin analogues and alpha interferon has demonstrated some clinical benefit.

IN CONCLUSION

Somatostatin analogues and alpha interferons are still playing an important role and considered to be first-line treatment in functioning and in non-functioning well-differentiated NETs, (G1-tumours) and somatostatin analogues might also be applied to control clinical symptoms in G2-tumours with higher proliferation.

The management of neuroendocrine tumours: current and future medical therapy options

Neuroendocrine tumours (NETs) are a genetically diverse group of malignancies that sometimes produce peptides causing characteristic hormonal syndromes. NETs can be clinically symptomatic (functioning) or silent (non-functioning); both types frequently synthesise more than one peptide, although often these are not associated with specific syndromes. Based on data from various sources, the incidence and prevalence of NETs is increasing. The primary treatment goal for patients with NETs is curative, with symptom control and the limitation of tumour progression as secondary goals. Surgery is the only possible curative approach and so represents the traditional first-line therapy. However, as most patients with NETs are diagnosed once metastases have occurred, curative surgery is generally not possible. Patients therefore require chronic postoperative medical management with the aim of relieving symptoms and, in recent years, suppressing tumour growth and spread. Somatostatin analogues, such as octreotide long-acting repeatable (LAR), can improve the symptoms of carcinoid syndrome and stabilise tumour growth in many patients. Results from the PROMID study show that octreotide LAR 30mg is an effective antiproliferative treatment in patients with newly diagnosed, functionally active or inactive, well-differentiated metastatic midgut NETs. An antiproliferative effect can also be achieved with everolimus, and combination therapy with octreotide LAR has shown synergistic antiproliferative activity. In the future, pasireotide, the multi-receptor targeted somatostatin analogue, has the potential to be an effective therapy for de novo or octreotide-refractory carcinoid syndrome and for inhibiting tumour cell proliferation. Peptide receptor radiotherapy with [90]yttrium-DOTATOC or [177]lutetium-DOTATE is also a new interesting treatment option for NETs.

Pancreatic endocrine tumors

Pancreatic endocrine tumors have been steadily growing in incidence and prevalence during the last two decades, showing an incidence of 4-5/1,000,000 population. They represent a heterogeneous group with very varying tumor biology and prognosis. About half of the patients present clinical symptoms and syndromes related to substances released from the tumors (Zollinger-Ellison syndrome, insulinoma, glucagonoma, etc) and the other half are so-called nonfunctioning tumors mainly presenting with symptoms such as obstruction, jaundice, bleeding, and abdominal mass. Ten percent to 15% of the pancreatic endocrine tumors are part of an inherited syndrome such as multiple endocrine neoplasia type 1 (MEN-1), von Hippel-Lindau (VHL), neurofibromatosis, or tuberousclerosis. The diagnosis is based on histopathology demonstrating neuroendocrine features such as positive staining for chromogranin A and specific hormones such as gastrin, proinsulin, and glucagon. Moreover, the biochemical diagnosis includes measurement of chromogranins A and B or specific hormones such as gastrin, insulin, glucagon, and vasoactive intestinal polypeptide (VIP) in the circulation. In addition to standard localization procedures, radiology (computed tomography [CT] scan, magnetic resonance imaging [MRI], ultrasound [US]), somatostatin receptor scintigraphy, and most recently positron emission tomography with specific isotopes such as (11)C-5 hydroxytryptamin ((11)C-5-HTP), fluorodopa and (68)Ga-1,4,7,10-tetra-azacyclododecane-N,N',N″,N‴-tetra-acetic acid (DOTA)-octreotate are performed. Surgery is still one of the cornerstones in the management of pancreatic endocrine tumors, but curative surgery is rarely obtained in most cases because of metastatic disease. Debulking and other cytoreductive procedures might facilitate systemic treatment. Cytotoxic drugs, biological agents, such as somatostatin analogs, alpha interferons, mammalian target of rapamycin (mTOR) inhibitors and tyrosine kinase inhibitors are routinely used. Tumor-targeted radioactive treatment is available in many centres in Europe and is effective in patients with tumors that express high content of somatostatin receptors type 2 and 5. In the future, treatment will be based on tumor biology and molecular genetics with the aim of so-called personalized medicine.

Management of neuroendocrine tumors: current and future therapies

Neuroendocrine tumors (NETs) are a genetically diverse group of malignancies that sometimes produce peptides that cause characteristic hormonal syndromes. NETs can be clinically symptomatic (functioning) or silent (nonfunctioning); both types frequently synthesize more than one peptide, although often these are not associated with specific syndromes. Based on data from various sources, the incidence and prevalence of NETs is increasing. The primary treatment goal for patients with NETs is curative, with symptom control and the limitation of tumor progression as secondary goals. Surgery is the only possible curative approach and so represents the traditional first-line therapy. However, as most patients with NETs are diagnosed once metastases have occurred, curative surgery is generally not possible. Patients therefore require chronic postoperative medical management with the aim of relieving symptoms and, in recent years, suppressing tumor growth and spread. Somatostatin analogues, such as octreotide long-acting repeatable (LAR), can improve the symptoms of carcinoid syndrome and stabilize tumor growth in many patients. Results from the placebo-controlled, double-blind, prospective randomized study on the effect of octreotide LAR in the control of tumor growth in patients with metastatic neuroendocrine midgut tumors (PROMID study) demonstrate that octreotide LAR 30 mg is an effective antiproliferative treatment in patients with newly diagnosed, functionally active or inactive, well-differentiated metastatic midgut NETs. An antiproliferative effect can also be achieved with everolimus, and combination therapy with octreotide LAR has shown synergistic antiproliferative activity. Sunitinib, a tyrosine kinase inhibitor, is active in pancreatic NETs. In the future, pasireotide, the multireceptor targeted somatostatin analogue, has the potential to be an effective therapy for de novo or octreotide-refractory carcinoid syndrome and for inhibiting tumor cell proliferation. Peptide receptor radiotherapy with ⁹⁰Yttrium-DOTATOC or ¹⁷⁷Lutetium-DOTATE is also a new interesting treatment option for NETs.

NANETS consensus guideline for the diagnosis and management of neuroendocrine tumors: well-differentiated neuroendocrine tumors of the thorax (includes lung and thymus)

Neuroendocrine tumors (NETs) of the thorax, including bronchial and thymic neuroendocrine NETs, are often referred to as NETs of the foregut. The incidence and prevalence of NETs are increasing in the United States as demonstrated in the Surveillance, Epidemiology, and End Results from 1973 to 2004 (J Clin Oncol. 2008;26[18]:3063-3072). Although the majority of bronchial and thymic NETs are sporadic, approximately 5% to 10% can be associated with hereditary syndrome, multiple endocrine neoplasms type 1 (Nat Rev Cancer. 2005;5[5]:367-375). Diagnosis is made by tissue pathology, allowing for characterization and classification of the NET. Radiologic evaluation is performed to determine the extent of disease involvement. Clinical symptoms from hormonal overproduction or from paraneoplastic processes are medically managed to improve patients' quality of life. Locoregional disease can be curative with surgery; however, distant or metastatic disease is rarely curable. Therapeutic options for metastatic/advanced NETs of the thorax are mainly to palliate symptoms. Final treatment recommendations for patients with either bronchial or thymic NETs should be individualized, weighing the risks and benefits of therapy.

The NANETS consensus guideline for the diagnosis and management of neuroendocrine tumors: well-differentiated neuroendocrine tumors of the Jejunum, Ileum, Appendix, and Cecum

Well-differentiated neuroendocrine tumors (NETs) of the jejunum, ileum, and appendix are also collectively known as midgut carcinoids. Similar to NETs in general, the diagnosed incidence of the midgut NETs is on the rise. Their presenting symptoms vary depending on stage and primary site. Local-regional NETs often present with vague and nonspecific symptoms. Classic carcinoid syndrome is more likely to appear in patients with advanced disease. Local-regional NETs of the small bowel should be resected whenever possible. With the exception of small well-differentiated NETs of the appendix, NETs of the midgut have substantial risk of relapse after resection and need to be followed for at least 7 years.Metastatic/advanced NETs of the midgut are incurable. Optimal management requires a multidisciplinary approach. Somatostatin analogs are effective in the management of carcinoid syndrome. Octreotide long-acting release has also recently been shown to delay disease progression. Liver-directed therapy and surgical debulking can improve quality of life in selected patients. Pivotal phase 3 studies with bevacizumab targeting vascular endothelial growth factor and everolimus targeting mTOR (mammalian target of rapamycin) are ongoing and may lead to improved outcome. Further studies of novel approaches such as peptide receptor radiotherapy are also warranted.

Pharmacotherapy of neuroendocrine cancers

BACKGROUND

Neuroendocrine tumors (NETs) of the diffuse neuroendocrine cell system often present a considerable diagnostic and therapeutic challenge.

METHODS

We have reviewed the literature on NET treatment between 1979 and 2008 (PubMed search: carcinoid or neuroendocrine tumor/tumour + treatment or management), and summarized current therapeutic options and recommendations.

RESULTS

The majority of tumors are diagnosed at a stage that the only curative treatment, radical surgical intervention, is no longer an option. Biotherapy with somatostatin analogs is currently the most efficient treatment to achieve palliation. The interferon class of agents may have a role in selected individuals but substantial adverse events often limit their use. Conventional chemotherapy has minimal efficacy but may have some utility in undifferentiated or highly proliferating neuroendocrine carcinomas and pancreatic NETs. Hepatic metastases, depending on size, location and number, may be amenable to surgical resection, embolization or radio-frequency ablation. Peptide receptor targeted radiotherapy may lead to reduction in tumor size but in most circumstances has a tumor-stabilizing effect. A variety of antiangiogenesis and growth factor-targeted agents have been evaluated but to date the results have failed to meet expectations. Thus, long-acting somatostatin analogs remain the only effective pharmacotherapeutic option that improves symptomatology and quality of life with minimal adverse effects.

Hepatic cytoreductive surgery for neuroendocrine cancer

Patients with gut-based metastatic neuroendocrine tumors (NET) often present late in the course of their slowly progressive disease, when cancer has extended beyond the point of reasonable expectation for surgical cure. At this stage of disease, the tumor's overwhelming hormonal production often significantly impairs the patient's quality of life. Unlike patients with other malignancies that might involve a heavy burden of hepatic metastatic disease, many patients with metastatic NET continue to live for a long time despite escalating hormone-related symptoms. This establishes the justification and rationale for cytoreduction, a noncurative surgical intervention that reduces tumor burden and hormonal burden and thereby can significantly increase symptom-free survival in the setting of an often slow but inevitable disease progression.

Neuroendocrine tumors. Biotherapy

This review gives an introduction to the classification and staging of neuroendocrine tumors, as the prognostic implications of these classifications influence therapeutic decisions. The indications for biotherapy are given, together with a short update on the mechanism of somatostatin analogs and interferon-alpha therapy. This is followed by an in-depth description of the use of biotherapy, its results with respect to symptomatic and antiproliferative treatment, as well as its side-effects.

Interferon-alpha and somatostatin analog in patients with gastroenteropancreatic neuroendocrine carcinoma: single agent or combination?

In most cases gastro-enteropancreatic neuroendocrine tumors grow slowly. Interferon-alpha and somatostatin analogs have shown symptomatic, biochemical, and, in a minority of cases, antiproliferative activity. Generally, they are proposed as single-agent therapy. However, based on in vitro and in vivo evidence, the combined use of these drugs was proposed in several non-randomized trials, indicating that there is an additive effect of the combination. Nevertheless, the three randomized trials published so far did not show a statistically significant survival benefit for the combination compared to the same agents alone, even though an advantage for the combination came out in all three studies. On the other hand, data from non-randomized trials would justify the sequential use of the two drugs or the combination after progression on single agent therapy. Therefore, at present the up-front combined use of interferon-alpha and somatostatin analog is not justified, whereas it could be indicated after progression to single-agent therapy. Further larger, international, prospective, randomized, multicentric clinical trials studying homogeneous populations would be necessary to give a final answer, but the rarity and heterogeneity of this malignancy does not assure that it will be possible.

Therapeutic options for gastrointestinal carcinoids

Although wide surgical resection is the optimal curative therapy for carcinoid tumors, in most patients the presence of metastatic disease at diagnosis usually renders excision a palliative procedure. This nevertheless decreases tumor burden, facilitates symptom control, and prevents complications caused by bleeding, perforation, or bowel obstruction resulting from fibrosis. In the stomach (types I and II) and rectum endoscopic excision may be adequate provided the lesion(s) are local. Long-term therapy is focused on symptom alleviation and improvement of quality of life using somatostatin analogues, particularly in a subcutaneous depot formulation. In some instances interferons may have a role but their usage often is associated with substantial adverse events. Conventional chemotherapy and external radiotherapy either alone or in a variety of permutations are of minimal efficacy and should be balanced against the decrease in quality of life often engendered by such agents. Hepatic metastases may be amenable to surgery, radiofrequency ablation, or embolization either alone or in combination with chemotherapeutic agents or isotopically loaded microspheres. Rarely hepatic transplantation may be of benefit although controversy exists as to its actual use. Peptide-receptor-targeted radiotherapy for advanced disease using radiolabeled octapeptide analogs (111In/90Yt/177Lu-octreotide) appear promising but data are limited and its status remains investigational. A variety of antiangiogenesis and growth factor-targeted agents have been evaluated, but as yet have shown little promise. The keystone of current therapy remains the long-acting somatostatin analogues that alleviate symptomatology and substantially improve quality of life with minimal adverse effects.

Treatment of neuroendocrine cancer metastatic to the liver: the role of ablative techniques

Carcinoid tumors and islet cell neoplasms are neuroendocrine neoplasms with indolent patterns of growth and association with bizarre hormone syndromes. These tumors behave in a relatively protracted and predictable manner, which allows for multiple therapeutic options. Even in the presence of hepatic metastases, the standard of treatment for neuroendocrine malignancy is surgery, either with curative intent or for tumor cytoreduction, i.e., resection of 90% or more of the tumor volume. Image-guided ablation, as either an adjunct to surgery or a primary treatment modality, can be used to treat neuroendocrine cancer metastatic to the liver. Image-guided ablative techniques, including radiofrequency ablation, alcohol injection, and cryoablation, can be used in selected patients to debulk hepatic tumors and improve patient symptoms. Although long-term follow-up data are not available, the surgical literature indicates that significant ablative debulking may improve patient survival. In this review, we discuss metastatic neuroendocrine disease and its treatment options, especially image-guided ablative techniques.

Chemotherapy and biotherapy in the treatment of neuroendocrine tumours

The medical treatment of neuroendocrine GEP tumours must be based on the growth properties of the tumour. Medical treatment includes chemotherapy, somatostatin analogues and alpha interferons. Chemotherapy has been particularly active in patients with high proliferating neuroendocrine tumours such as endocrine pancreatic tumours and lung carcinoids. Streptozotocin-based combinations including 5-flourouracil and doxorubicin have generated partial remissions in 40%-60% of the patients giving a median survival of about two years in patients with advanced disease. Cisplatinum plus etoposide have demonstrated significant antitumour effects in anaplastic endocrine pancreatic tumours and lung carcinoids. However, in low proliferating tumours such as classical midgut carcinoids the response rates with the same combinations of cytotoxic agents have only generated short lasting responses in less than 10% of patients. In these patients, biological treatment has been of benefit. Alpha interferon at doses of 3-9 million units three to seven times per week subcutaneously, has given biochemical response rates of 50% and significant tumour reduction in about 15% of patients with long duration, up to three years. Somatostatin analogues have been widely used in the treatment of neuroendocrine gut and pancreatic tumours. The currently available somatostatin analogues particularly bind somatostatin receptor 2 and 5 and with low affinity also receptor subtype 3. Octreotide is registered in most countries for the treatment of patients with carcinoid syndrome and also VIP and glucagon producing tumours. Regular octreotide at standard doses of 100-300 microg/day gives symptomatic responses in a medium of 60% of patients and biochemical responses in up to 70% of patients. Significant tumour responses are rare, less than 5%. Long-acting formulations of somatostatin analogues have been of significant benefit for the patients with similar response rates as for regular formulations. The quality of life has been significantly improved by using the long-acting formulations.

Diagnostic, surgical and medical aspect of the midgut carcinoids

This review covers the incidence, prognosis, diagnosis and treatment of midgut carcinoids with emphasis on the surgical and peri-operative aspects. Midgut carcinoids are rare neuro-endocrine tumours which become manifest once they have metastasized to the liver. Treatment of metastatic disease may include radical resection but is usually palliative. The tumour grows relatively slow. Besides the biochemical effects resulting in the carcinoid syndrome, patients may suffer from mechanical mass effects of the tumour. Medical treatment can alleviate the biochemical effects of the tumour, but has a limited effect on tumour growth. The introduction of octreotide was a milestone in palliation of these symptoms and has led to more aggressive treatment protocols. Treatment aimed at cytoreduction of hepatic metastasis and diminished secretion of bioactive amines may achieve good palliation. Cytoreduction may be performed by means of surgery, hepatic arterial ligation, (chemo)embolization, cryosurgery, radio-frequency ablation, internal radiation or even liver transplantation. The role of these options will be discussed in this review.

Efficacy and safety of prolonged-release lanreotide in patients with gastrointestinal neuroendocrine tumors and hormone-related symptoms

PURPOSE

To evaluate the prolonged release (PR) of the long-acting somatostatin analog lanreotide in patients with gastrointestinal neuroendocrine tumors and its effect on hormone-related symptomatology, tumor markers, tumor size, tolerability, and quality of life (QOL).

PATIENTS AND METHODS

Eligible patients had the following substantial daily symptoms: for patients with carcinoid tumors, three or more stools and/or 1.5 or more flushing episodes; for patients with gastrinoma, greater than 50% elevated basic acid output; and for patients with vasoactive intestinal peptide-secreting tumors (VIPomas), four or more stools and/or a stool volume of >/= 800 mL, a measurable tumor, and an elevated biochemical tumor marker (>/= two times the upper limit of the normal reference range). Lanreotide PR was administered intramuscularly every 14 days at 30 mg for 6 months. We measured efficacy by studying symptoms, tumor markers, tumor size, and QOL. Side effects were scored according to the National Cancer Institute's toxicity grading system and ultrasound examination of the gallbladder.

RESULTS

Fifty-five patients were included in the study (48 patients with carcinoid tumors, six patients with gastrinoma, and one patient with VIPoma). Symptomatic improvement (> 50% reduction) occurred in 38% of the assessable patients with carcinoid tumors, in 67% of the gastrinoma patients, and in the VIPoma patient. Tumor markers normalized in two of 45 assessable patients, 19 patients exhibited a reduction (> 50%), 19 patients exhibited no change, and tumor markers rose by more than 50% in five patients. Tumor size was reduced in two of 31 assessable patients and remained stable in 25 patients; four patients experienced progression. QOL assessments after 1 month showed improvements in emotional and cognitive function, and diminished fatigue, sleeping disorders, and diarrhea. Eight of 30 assessable patients developed gallstones.

CONCLUSION

Lanreotide PR is a well-tolerated somatostatin analog with significant clinical, biochemical, and antitumor effects that bring about a significant improvement in QOL for patients with neuroendocrine tumors.

Treatment of advanced medullary thyroid carcinoma with a combination of recombinant interferon alpha-2b and octreotide

BACKGROUND

The medical treatment of advanced medullary thyroid carcinoma (MTC) is still questionable. Results of chemotherapy are disappointing with almost no curative responses, few partial responses, and many side-effects. A recent report has suggested the activity of combination recombinant interferon alpha-2b (rIFN-alpha-2b) and octreotide, a somatostatin analogue, in the treatment of a metastatic carcinoid tumor. This new therapeutic schedule may be used in other neuroendocrine tumors. In this study we evaluated the therapeutic effectiveness of octreotide and rIFN-alpha-2b in patients with advanced MTC.

METHODS

Eight patients affected by advanced MTC received octreotide at a daily dose of 150 micrograms for 6 months and subsequently at a daily dose of 300 micrograms for another 6 months, subcutaneously, and rIFN-alpha-2b at a daily dose of 5.000.000 IU intramuscularly 3 times a week for 12 months. Plasma calcitonin, carcinoembryonic antigenic levels, and morphologic staging were evaluated at 0, 1, 3, 6, and 12 months.

RESULTS

The therapy was stopped in two patients because of diarrhea and toxicity of drugs used. Pre-existing diarrhea in four patients and flushing in one significantly improved during treatment. A maximum decrease of calcitonin was reached after 1 month in 2 patients and after 3 months in 4. In all of the patients carcinoembryonic antigen levels decreased during treatment. No significant changes of size of metastases were observed.

CONCLUSIONS

The combination of octreotide and interferon is well tolerated and can be recommended for the treatment of advanced MTC.

Neuroendocrine gastrointestinal tumours

Neuroendocrine gut and pancreatic tumours have provided a diagnostic and therapeutic challenge over the years. These rather slowly growing neoplasms have been assigned a good prognosis but when liver metastases are present the prognosis is not better than that of most other malignant tumours. Despite the development of improved diagnostic procedures many patients are still referred at a stage of the disease too late for surgical cure, at which time medical treatment is warranted. The diagnosis is based on histopathological diagnosis including silver stainings (Grimelius, Masson) and immunohistochemistry for chromogranin A and synaptophysin. Analysis of chromogranin A in the plasma is an important adjunct in the screening for various types of neuroendocrine gut and pancreatic tumours. About 80%-100% of patients with verified neuroendocrine gastrointestinal tumours have elevated circulating levels of this glycoprotein. Depending on clinical symptoms the chromogranin A analysis is supplemented by other peptide hormone analyses as well as urinary 5-HIAA for patients with midgut carcinoid tumours. In the past the localization procedures were based on CT, MRI and ultrasound investigations but in recent years somatostatin receptor scintigraphy (octreoscan) and endoscopic ultrasonography have significantly improved the diagnostic potential. Almost 80% of neuroendocrine gastrointestinal tumours present somatostatin receptor subtype 2 binding 111Indium-labelled octreotide which can be used for staging of the disease, and which also indicates whether or not somatostatin analogues can be used in the treatment of these tumours. Surgery is still a cornerstone in the treatment of neuroendocrine gastrointestinal tumours, even if the patients are beyond cure. Debulking procedures and bypassing operations are important for improving clinical condition and facilitating impending medical treatment, and during the past decade a more aggressive surgical approach has emerged. The medical treatment is based on chemotherapy, and the use of somatostatin analogues and alpha-interferons. Chemotherapy, in particular the combination of streptozotocin with 5-FU or doxorubicin, is still first-line treatment for most endocrine pancreatic tumours, while somatostatin analogues and alpha-interferons are considered first-line for classical midgut carcinoids. Chemotherapy and biotherapy can be combined in many patients, and changes from one medical treatment to another during the course of the disease is mandatory for control of the disease. It is important to realise that most patients with malignant tumours are not cured by medical treatment but that the disease can be controlled for extended periods of time. In the future it will be possible to individualize treatments on the basis of new information about such features of tumour biology as proliferation capacity, expression of adhesion molecules, and growth factors and their receptors.

Orthotopic liver transplantation in the treatment of metastatic neuroendocrine tumors of the liver

The place of orthotopic liver transplantation (OLT) in the management of metastatic hepatic neuroendocrine tumors has not been adequately defined. The present report is concerned with patient survival, disease recurrence, and symptom relief in 11 such patients in a single center who, at the time of transplantation, had no extrahepatic tumor. All patients obtained complete symptom relief initially but tumor recurrence was observed in 6 of the 11 cases (5 carcinoid and 1 apudoma) at a median of 11 months (range 3.5-26). Five patients have died, 4 in the carcinoid group with recurrence and one from chronic rejection in the other apudoma group. Of the 6 patients currently alive one of 2 carcinoids and one of 4 other apudomas have tumor recurrence. Recurrent deposits were found predominantly in bone and in the transplanted liver. Actuarial survival post transplant was 82% and 57% at 1 and 5 years respectively. It is concluded that OLT is effective at controlling symptoms from secreting carcinoid deposits in the liver. Although the tumor will recur in most cases, this is not necessarily associated with early return of symptoms. Prolonged disease free survival is more likely in the non carcinoid apudoma group.

Neoplastic lesions of the appendix

Neoplasms occur in 0.5 per cent of appendices. Ultrasonography or computed tomography is beneficial, but preoperative detection is rare. At operation, the diagnosis is considered in under half of cases. Mucocele, localized pseudomyxoma peritonei, benign tumours and most appendiceal carcinoids are cured by appendicectomy alone. Right hemicolectomy is indicated for: (1) invasive adenocarcinoma; (2) tumours close to the caecum; (3) lesions larger than 2 cm; (4) mucin production; (5) invasion of the lymphatics, serosa or mesoappendix; and (6) cellular pleomorphism with a high mitotic rate. Tumours of 1-2 cm, small mucinous carcinoids, adenocarcinoma confined to the mucosa, and tumours in children may be treated by appendicectomy alone at the surgeon's discretion. The 5-year survival rate associated with classical carcinoid is more than 90 per cent. The prognosis of mucinous carcinoid is intermediate between that of classical carcinoid and well differentiated adenocarcinoma. The prognosis of adenocarcinoma is determined by Dukes' stage and is similar, stage for stage, to that of colorectal carcinoma.

Cytokine-based biotherapy of gastrointestinal tumors

Over the past 20 years the administration of cytokines has emerged as an important fourth modality for the treatment of human cancer. Advances in the field of therapy of gastrointestinal tumors have become a major focus of current research, given the lack of progress of conventional antineoplastic therapy in most of these tumors. Among the heterogeneous group of gastrointestinal malignancies, novel therapeutic strategies have been employed for each individual tumor type, and cytokines (interferon-alpha) have gained an established role in the treatment of advanced carcinoid tumors. Although our understanding of the mechanisms of biological response modification is still limited, further improvement in the management of gastrointestinal malignancies can be expected from multimodality therapy regimens employing cytokines in combination with other biological response modifiers, chemotherapeutic agents, active-specific immunotherapy, and immunotoxin- and radionuclide-conjugated monoclonal antibodies. A wide range of clinical and preclinical studies have been conducted in colorectal carcinoma; however, potential therapeutic benefit of cytokine-based biotherapy has not been fully defined. Therefore, largescale, i.e., multicenter, studies are required to quantify the potential therapeutic effects of cytokines in gastrointestinal tumors.