Clinical efficacy of octreotide in the treatment of metastatic neuroendocrine tumors. A study by the Italian Trials in Medical Oncology Group

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.

Radioembolization with yttrium-90 microspheres: a state-of-the-art brachytherapy treatment for primary and secondary liver malignancies: part 3: comprehensive literature review and future direction

Treatment options for primary and secondary liver tumors that cannot be resected or ablated are based on transarterial techniques. Although the majority of these are based on bland and chemoembolization techniques, yttrium-90 microspheres represent an alternate transarterial option. Although the amount of literature on (90)Y does not rival that of bland or chemoembolization, there nevertheless are ample data that support its use for primary and metastatic liver tumors. A comprehensive review of the entire available literature dating from the early 1960s is presented, as is a discussion of the possibilities for future research with use of radioembolization as a platform.

Role of somatostatin analogs in the clinical management of non-neuroendocrine solid tumors

The somatostatin analogs octreotide, lanreotide and RC-160 (vapreotide) are known to have direct and indirect antitumor effects. Direct effects include the arrest of tumor growth and stimulation of apoptosis, resulting in tumor shrinkage. Indirect antiproliferative effects may occur through antiangiogenesis, immunomodulatory effects and the suppression of tumor-stimulating growth factors. With a safety profile of somatostatin analogs established over 20 years of clinical use in the treatment of neuroendocrine tumors, somatostatin analogs are attractive therapeutic options for patients with non-neuroendocrine tumors. In early clinical trials of somatostatin analogs, however, some cancer patients responded well, while others showed a lack of benefit. This variability in clinical response may reflect the selective binding affinities of octreotide, lanreotide and RC-160, which bind with high affinity to just two of the five different somatostatin receptor subtypes. Treatment response may therefore depend on the specific receptor subtype(s) present in the tumor, the relative proportion of receptor(s) expressed on the tumor cell surface and the absolute quantity of each receptor subtype. Greater understanding of the role of somatostatin receptors, their binding affinities and modes of action has led to increased research into the use of somatostatin analogs, particularly octreotide, in cancer treatment as monotherapies, in combination with hormonal treatments and cytotoxic therapies, and in both adjuvant and neoadjuvant settings. A review of the literature suggests that the antitumor potential of somatostatin analogs should be investigated further and additional studies might determine how these analogs can best be used to improve the treatment of patients with non-neuroendocrine tumors.

Rationale for the use of somatostatin analogs as antitumor agents

BACKGROUND

There is a need for novel antitumor agents that demonstrate efficacy in currently refractory tumors without adding to the toxicity of therapy. The somatostatin analogs, which have demonstrated antineoplastic activities in experimental tumor models, and good tolerability and safety profiles are attractive candidates.

MATERIALS AND METHODS

Data from preclinical studies provide evidence for direct and indirect mechanisms by which somatostatin analogs exert antitumor effects.

RESULTS

Direct antitumor activities, mediated through somatostatin receptors (sst(1)-sst(5)) expressed in tumor cells, include blockade of autocrine/paracrine growth-promoting hormone and growth factor production, inhibition of growth factor-mediated mitogenic signals and induction of apoptosis. Indirect antitumor effects include inhibition of growth-promoting hormone and growth factor secretion, and antiangiogenic actions. Many human tumors express more than one somatostatin receptor subtype, with sst(2) being predominant. Somatostatin analogs such as octreotide and lanreotide, which present a high affinity for sst(2), are in current clinical use to alleviate symptoms in patients with endocrine tumors, and radiolabeled somatostatin analogs have been developed for diagnosis and radiotherapy.

CONCLUSIONS

While the rationale exists for the use of somatostatin analogs as antitumor agents, studies are ongoing to identify analogs with activity across the range of receptor subtypes to maximize the potential of such treatment.

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.

A phase II trial of irinotecan and cisplatin in patients with metastatic neuroendocrine tumors

The role of systemic chemotherapy in the treatment of patients with metastatic neuroendocrine tumors is controversial. While combination regimens containing cisplatin and etoposide have activity against more aggressive neuroendocrine tumor variants, such regimens appear to have little efficacy in patients with well-differentiated neuroendocrine tumor subtypes. The combination of irinotecan and cisplatin is active both against small cell lung cancer and in upper gastrointestinal malignancies but has not been prospectively evaluated in patients with metastatic neuroendocrine tumors. We therefore assessed the efficacy of an irinotecan/cisplatin combination in patients with this disease. Eighteen patients with metastatic neuroendocrine tumors (excluding small cell carcinoma) were treated with irinotecan, 65 mg/m2, and cisplatin, 30 mg/m2, administered weekly for 2 of every 3 weeks. Patients were followed for evidence of toxicity, response, and survival. The toxicities associated with this regimen were mild and included myelosuppression, nausea, and diarrhea. Only one radiologic response was observed among four patients with poorly differentiated neuroendocrine tumors. No radiologic responses were observed in 14 patients with well-differentiated tumors. The median overall survival duration of patients treated with this regimen was 11.4 months. We conclude that while the combination of irinotecan and cisplatin may have activity in aggressive neuroendocrine tumor subtypes, this combination is inactive in patients with well-differentiated neuroendocrine tumors.

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.

Merkel cell cancer of the skin

Merkel cell carcinoma (MCC) is a rare malignant cutaneous tumor of the elderly with rapidly growing skin nodules found predominantly on sun-exposed areas of the body. The vast majority of patients present with localized disease, while up to 30% have regional lymph node metastases. Despite local excision and the incidence of local recurrence, regional lymph node metastases and distant metastases is high and usually occurs within 2 years of primary diagnosis. The optimal treatment for patients with MCC remains unclear. The best outcome is achieved with multidisciplinary management including surgical excision of primary tumor with adequate margins and post-operative radiotherapy (RT) to control local and regional disease. Patients with regional nodal metastases should be treated with lymph node dissection plus RT. Adjuvant chemotherapy (CT) should be considered as part of the initial management. In case of metastatic disease CT based on regimens used for small-cell lung cancer is the standard treatment of care.

[Surgical treatment of gastric, enteric pancreatic endocrine tumors. Part 2. treatment of hepatic metastases]

The development of hepatic metastases (HM) marks a turning point in the evolutionand prognosis of well-differentiated endocrine tumors (ET). Management is usually multicisciplinary (chemotherapy, arterial chemo-embolization, percutaneous ablation, somatostatin analogs, biotherapy, and surgery). A thorough pre-operative work-up is neecessary to exclude extrahepatic disease and to detect tiny HM's. Complete resection (RO) is the only curative treatment for well-differentiated ET with HM. The type of resection is specific to each case and may range from wedge resection of a metastasis to complex hepatectomy with simultaneous resection of the primary ET. Cytoreductive surgery may be indicated for palliation when medical therapy fails to control endocrine symptoms. Operative mortality is low (0-6%) and global survival is 60-70% afterafter R) resection of HM of well-differentiated ET's. After resection of HM involving only one hepatic lobe, 5 year survival is better than 90%. When HM are multiple, bilobar and synchronous, the prognosis is very poor--only 10% of such patients can have a complete resection and this often requires a long prologue of ancillary procedures (chemotherapy, chemoembolization, portal vein ligation, percutaneous ablation). Hepatic transplantation (HT) has only a limited rôle in the treatment of HM for ET; mortality is high when HT is associated with large and complex resections, i.e. pancreaticoduodenectomy. Although there is no consensus in the literature, HT should be limited to the most optimal cases (young, good general health, well-differentiated tumor, slow evolution, complete resection of the primary rumor, and unresectable liver metastases). Global survival for HT in patients with ET is 60% at 2 years, 47% at 5 years; tumor-free survival at 5 years is 24%. HT for HM has better survival results for ET's of intestinal origin (carcinoids) than for duodenopancreatic ET's.

Gastrinoma of the stomach: a case report

Gastrinomas of the stomach are extremely rare endocrine tumors producing Zollinger-Ellison syndrome. We report here the case of a patient with gastrinoma of the stomach who presented regional and hepatic metastases at the time of diagnosis. The endocrine tumor was discovered incidentally 8 yr after the onset of symptoms related to peptic ulcer, which responded to medical treatment with a proton pump inhibitor. Surgery did not cure the patient, as demonstrated by provocative tests showing serum gastrin responses indicative of residual disease. A long-term treatment with the somatostatin analog lanreotide induced a biochemical response and was associated with a substantially stable disease.

MRI of merkel cell carcinoma: histologic correlation and review of the literature

OBJECTIVE

The objective of this study was to determine the MRI characteristics of Merkel cell carcinoma, with an emphasis on histologic correlation.

MATERIALS AND METHODS

The demographic information about 15 patients from our institution and their MRI examinations were retrospectively reviewed by three musculoskeletal radiologists by consensus for lesion location and intrinsic characteristics. The study group was composed of three women and 12 men who ranged in age from 48 to 87 years, with a mean age of 75 years. Histology results of resected specimens were reviewed in all cases and were correlated with imaging.

RESULTS

MRI showed skin thickening, subcutaneous reticular stranding (n = 9, 60%); multiple anatomically aligned subcutaneous soft-tissue masses, representing lymphatic tumor nodules (n = 5, 33%); lymph node enlargement with fine, compressed, retained fatty tissue (n = 5, 33%); nodal necrosis (n = 1); and perifascial and intramuscular metastases (n = 2). Histology confirmed the lymphatic nature of the soft-tissue Merkel cell tumors.

CONCLUSION

Patients with Merkel cell tumors may present at imaging with subcutaneous lymphatic reticular stranding, multiple subcutaneous masses, and lymph node metastases. Often there is massive lymph node enlargement with fine, compressed, retained fatty tissue.

Prognosis of Carcinoid Heart Disease

BACKGROUND

The long-term prognosis of patients who develop carcinoid heart disease and the effect of cardiac surgery on outcome are not well established.

METHODS AND RESULTS

In this retrospective study, we identified 200 patients with carcinoid syndrome referred for echocardiography in whom the diagnosis of carcinoid heart disease was confirmed. Patients were divided into 3 groups of similar size according to the date from first diagnosis of carcinoid heart disease. Group A comprised patients diagnosed from 1981 through June 1989; group B, diagnosed July 1989 through May 1995; and group C, June 1995 through 2000. The end point was all-cause mortality. Median survival was significantly lower in group A (1.5 years, 95% CI 1.1 to 1.9 years) compared with groups B (3.2, 95% CI 1.3 to 5.1 years) and C (4.4, 95% CI 2.4 to 7.1 years; P=0.009). In a multivariate model adjusted for treatment and clinical characteristics, the risk of death in groups B (hazard ratio 0.67, 95% CI 0.46 to 0.99, P=0.04) and C (hazard ratio 0.61, 95% CI 0.39 to 0.92, P=0.006) was significantly reduced relative to group A. Cardiac surgery was performed in 87 patients. When cardiac surgery was included as a time-dependent covariate in a multivariate analysis, it was associated with a risk reduction of 0.48 (95% CI 0.31 to 0.73, P<0.001), whereas the time period of diagnosis was no longer significant.

CONCLUSIONS

The prognosis of patients with recognized carcinoid heart disease has improved over the past 2 decades at our institution. This change in survival may be related to valve replacement surgery.

Endocrine tumours of the pancreas

Endocrine pancreatic tumours (EPTs) are uncommon tumours occurring in approximately 1 in 100,000 of the population, representing 1-2% of all pancreatic neoplasms. Some of the tumours may be part of multiple endocrine neoplasia type one (MEN-1) syndrome or von Hippel-Lindau (vHL) disease. EPTs are classified as functioning or non-functioning tumours on the basis of their clinical manifestation. The biochemical diagnosis of EPT is based on hormones and amines released. Besides specific markers such as insulin, there are also general tumour markers such as chromogranin A, which is the most valuable marker and has been reported to be increased in plasma in 50-80% of patients with EPTs and correlates with tumour burden. The location of endocrine tumours of the pancreas includes different techniques, from endoscopic investigations to scintigraphy (e.g. somatostatin receptor scintigraphy) and positron emission tomography. The medical treatment of endocrine pancreatic tumours consists of chemotherapy, somatostatin analogues and alpha-interferon. None of these can cure a patient with malignant disease. In future, therapy will be custom-made and based on current knowledge of tumour biology and molecular genetics.

Phase II/III Study of Doxorubicin With Fluorouracil Compared With Streptozocin With Fluorouracil or Dacarbazine in the Treatment of Advanced Carcinoid Tumors: Eastern Cooperative Oncology Group Study E1281

Purpose

Optimal treatments for metastatic carcinoid tumor remain undefined, and the role of chemotherapy for symptomatic patients with progressive disease is uncertain.

Patients and Methods

Two hundred forty-nine patients with advanced carcinoid tumors were randomized to either doxorubicin with fluorouracil (FU/DOX) or streptozocin with fluorouracil (FU/STZ). Patients crossed over to the dacarbazine (DTIC) treatment after disease progression following first-line treatment (either FU/DOX or FU/STZ), and 73 patients were assigned to one of these three treatments based on their previous treatment or on abnormal baseline cardiac or renal function.

Results

In the randomized group, there was no difference between FU/DOX and FU/STZ in response rates (15.9% v 16%) and progression-free survival (4.5 v 5.3 months). FU/STZ (24.3 months) was superior to FU/DOX (15.7 months; P = .0267) in median survival. The response rate of crossover DTIC treatment was 8.2%, with a median survival of 11.9 months. Hematologic toxicities were the major treatment-related toxicities for both FU/DOX and FU/STZ, and mild to moderate renal toxicity was reported in 40 (34.8%) of 115 patients in the FU/STZ arm.

Conclusion

Response to all three treatment regimens were modest. FU/STZ improved survival compared with the doxorubicin-based regimen, suggesting that the combination should be considered to be an active regimen of therapy when chemotherapy is judged to be an option for selected patients with carcinoid tumors.

Endocrine tumours of the gastrointestinal tract. Biotherapy for metastatic endocrine tumours

Somatostatin analogues have been the mainstay of symptomatic management of patients with neuroendocrine tumours (NETs) for two decades with the main mechanism of action being inhibition of peptide release. Evidence base for interferon use is perhaps less clear. It may contribute to symptom control by abrogating peptide release, and there is some evidence that it has an anti-proliferative action. Combination of somatostatin analogues and interferon provides symptom control, mainly by effecting a reduction in the amount of circulating, physiologically active, peptide hormones. Treatment can also provide disease stabilisation in a proportion of patients. In a minority of patients treatment may lead to partial response.

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.

Endocrine tumours of the gastrointestinal tract. Somatostatin receptors as tools for diagnosis and therapy: molecular aspects

Somatostatin is a neuropeptide that acts as an endogenous inhibitor of various cellular functions including endocrine and exocrine secretions and the proliferation of normal and tumour cells. Its action is mediated by a family of G-protein-coupled receptors (sst1-sst5) that are widely distributed in normal and tumour cells. Gastroenteropancreatic endocrine tumours express multiple somatostatin receptors, sst2 being clearly predominant. These receptors represent the molecular basis for the clinical use of somatostatin analogues in the treatment of endocrine tumours and their in vivo localisation. This review covers current knowledge in somatostatin receptor biology and signalling.

Merkel cell carcinoma of skin: diagnosis and management strategies

Merkel cell carcinoma (MCC) of the skin is a rare form of cutaneous malignancy of neuroendocrine origin with a propensity to affect predominately elderly patients in sun-exposed areas. The tumour has an extremely aggressive growth pattern with the potential to seed into the dermal lymphatics at an early stage as well as spread to nodes and distant sites. Successful outcomes can be achieved with early diagnosis and a multidisciplinary approach to management. Patients with MCC should be carefully staged to exclude distant metastatic disease. Treatment should be approached with both the primary site and the lymph nodes in mind. The primary site should be excised with clear margins, followed by postoperative radiotherapy to the primary site and affected nodes. Addition of chemotherapy to patients perceived to be at high-risk of distant recurrence (e.g. those with involved nodes) has been considered, but evidence supporting this approach is relatively scant. This treatment strategy needs to be approached with caution in the elderly because of the risk of myelosuppression. An aggressive treatment approach is warranted at the first attempt to treat MCC as treatment for recurrent disease is less likely to be successful.

Is the new WHO classification of neuroendocrine tumours useful for selecting an appropriate treatment?

BACKGROUND

Neuroendocrine tumours (NETs) are a rare and heterogeneous group of neoplasms. The most recent WHO classification provides clinical tools and indications to make the diagnosis and to suggest the correct treatment in different subgroups of patients. The aim of this trial was to apply the new classification criteria in clinical practice and, accordingly, to choose the most appropriate treatment.

PATIENTS AND METHODS

Thirty-one evaluable patients, not previously treated, classified as advanced well differentiated NETs according to the new classification, were given long-acting release octreotide 30 mg every 28 days until evidence of disease progression. The treatment activity was evaluated according to objective, biochemical and symptomatic responses. Safety and tolerability were also assessed.

RESULTS

Two partial objective tumour responses were obtained (6%), stabilization occurred in 16 patients (52%) and 95% of patients had a disease stabilisation lasting > or =6 months. However, eight patients showed rapid disease progression within 6 months of therapy and six patients after 6 months. Biochemical responses, evaluated by changes in serum chromogranine A levels were reported in 20/24 patients (83%). Symptomatic responses were observed in 6/14 patients (43%): a complete syndrome remission in one patient, partial syndrome remission in five patients, no change in four patients and progressive disease in four patients. The median overall survival was not reached, and the median time to disease progression was 18 months (range 1-49 months). The treatment was well tolerated, no severe adverse events were observed and no patient withdrew from the study because of adverse events.

CONCLUSIONS

The WHO classification enables identification of low-grade NET patients who may be suitable for hormonal treatment. Octreotide LAR was seen to be effective in controlling the disease and was well tolerated. However, eight patients failed to respond to the treatment, despite histological evidence of a well differentiated tumour according to the new classification. This suggests that further histological examination should be carried out, especially in patients with visceral metastases and a short disease-free interval.

Current status of gastrointestinal carcinoids

Gastrointestinal (GI) carcinoids are ill-understood, enigmatic malignancies, which, although slow growing compared with adenocarcinomas, can behave aggressively. Carcinoids are classified based on organ site and cell of origin and occur most frequently in the GI (67%) where they are most common in small intestine (25%), appendix (12%), and rectum (14%). Local manifestations--mass, bleeding, obstruction, or perforation--reflect invasion or tumor-induced fibrosis and often result in incidental detection at emergency surgery. Symptoms are protean (flushing, sweating, diarrhea, bronchospasm), usually misdiagnosed, and reflect secretion of diverse amines and peptides. Biochemical diagnosis is established by elevation of plasma chromogranin A (CgA), serotonin, or urinary 5-hydroxyindoleacetic acid (5-HIAA), while topographic localization is by Octreoscan, computerized axial tomography (CAT) scan, or endoscopy/ultrasound. Histological identification is confirmed by CgA and synaptophysin immunohistochemistry. Primary therapy is surgical excision to avert local manifestations and decrease hormone secretion. Hepatic metastases may be amenable to cytoreduction, radiofrequency ablation, embolization alone, or with cytotoxics. Hepatic transplantation may rarely be beneficial. Chemotherapy and radiotherapy have minimal efficacy and substantially decrease quality of life. Intravenously administered receptor-targeted radiolabeled somatostatin analogs are of use in disseminated disease. Local endoscopic excision for gastric (type I and II) and rectal carcinoids may be adequate. Somatostatin analogues provide the most effective symptomatic therapy, although interferon has some utility. Overall 5-year survival for carcinoids of the appendix is 98%, gastric (types I/II) is 81%, rectum is 87%, small intestinal is 60%, colonic carcinoids is 62%, and gastric type III/IV is 33%.

Lack of efficacy of streptozocin and doxorubicin in patients with advanced pancreatic endocrine tumors

BACKGROUND

The combination of streptozocin and doxorubicin has been considered the standard palliative chemotherapy regimen in patients with advanced pancreatic endocrine tumors (PETs). However, a recent review failed to confirm high antitumor activity in patients with advanced PETs.

METHODS

We retrospectively reviewed the records of 16 consecutive patients who received streptozocin and doxorubicin for advanced PETs at Dana Farber/Partners Cancer Care institutions. Baseline patient characteristics, radiographic response to therapy, treatment-related toxicity, progression-free and overall survival were analyzed.

RESULTS

One patient demonstrated an objective partial response to therapy (objective response rate [ORR], 6%; 95% confidence interval [CI], 0-18%). Six patients achieved stable disease (38%; 95% CI, 14-62%) and 9 patients demonstrated disease progression on initial restaging (56%; 95% CI, 33-77%). The median progression-free survival and overall survival were 3.9 months (95% CI, 2.8-8.8) and 20.2 months (95% CI, 9.7-37.4), respectively.

CONCLUSIONS

In this retrospective cohort, the combination of streptozocin and doxorubicin failed to demonstrate substantial antitumor activity in patients with advanced PET. Our findings underscore the need for new therapeutic options in this patient population.

Regression of liver metastases of occult carcinoid tumor with slow release Lanreotide therapy

Few clinical studies have demonstrated an anti-proliferative activity of somatostatin (SST) analogs in carcinoids. We report the case of a woman with liver metastases of neuroendocrine tumor and no evidence of the primary tumor. The liver metastases were characterized by high proliferation index, immunoreactiviy for somatostatin receptor (SSTR)-1, 2, 3 and 5 and positive octreoscan. Urinary 5-hydroxyindolacetic acid, serum serotonin and chromogranin A were elevated. Slow release lanreotide (SR-LAN) therapy for 3 mo controlled clinical and biochemical signs of carcinoid tumor and caused a clear-cut reduction in the diameter of two liver metastases and disappearance of another lesion, with further reduction after 6 and 18 mo. We demonstrated a clear-cut long-lasting anti-proliferative effect of SR-LAN on liver metastases of occult carcinoid with high proliferation index and immunoreactivity for SSTR-1, 2, 3, and 5. Immuno-histochemistry for SSTRs could be a suitable method for the selection of patients with metastatic carcinoid that may benefit from SST analog therapy.

Somatostatin analogues in the treatment of gastroenteropancreatic neuroendocrine tumors

Gastroenteropancreatic neuroendocrine tumors constitute a heterogeneous group of neoplasms that are often associated with typical symptoms due to excessive and uncontrolled release of diverse hormones. Because these tumors are usually slow growing, surgery is the cornerstone of treatment. However, these rare tumors can present with rapid progression that requires aggressive systemic therapy or diffuse metastatic disease not amenable to surgical palliation. For most patients, medical approaches are necessary at some point in the course of their disease, especially since most tumors are at an advanced stage at the time of diagnosis. Most gastroenteropancreatic neuroendocrine tumors express high levels of somatostatin receptors, which are bound by somatostatin or its synthetic analogues. These agents, alone or combined with other therapies, such as Interferon or radioisotopes, are therefore used frequently to control hormone-related symptoms and, for some patients, the growth of the disease Itself. This article reviews the evidence for the use of somatostatin analogues in the treatment of gastroenteropancreatic neuroendocrine tumors based on a MEDLINE search of literature published from January 1970 to July 2003.

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.

The management of advanced thyroid cancer

Although the prognosis of the majority of patients with thyroid cancer is excellent there are some patients with advanced thyroid cancer in whom the prognosis is poor. Such patients include: patients with locally invasive or recurrent differentiated thyroid cancer and medullary thyroid cancer, and all patients with anaplastic cancer. The management of patients with advanced thyroid cancer is reviewed with emphasis on the role of external beam radiotherapy.

Fluorouracil, doxorubicin, and streptozocin in the treatment of patients with locally advanced and metastatic pancreatic endocrine carcinomas

PURPOSE

The role of systemic chemotherapy in the management of pancreatic endocrine carcinoma (islet cell carcinoma; PEC) is an area of considerable controversy. Response rates ranging from 6% to 69% have been reported for streptozocin-based chemotherapy. We retrospectively studied 84 patients with locally advanced or metastatic PEC who had been treated with fluorouracil, doxorubicin, and streptozocin (FAS) to determine the objective response rate, duration of progression-free survival (PFS), and duration of overall survival (OS).

PATIENTS AND METHODS

Eligible patients had histologic or cytologic confirmation of their tumor and measurable disease on computed tomography or magnetic resonance imaging scans. Response to treatment was evaluated in this study using the new international criteria proposed by the Response Evaluation Criteria in Solid Tumors Committee.

RESULTS

Sixty-one of the patients were male and 23 were female, with a median age of 54 years (range, 24 to 78 years). The response rate (RR) to FAS was 39%, with a median response duration of 9.3 months. The 2-year PFS rate was 41%, and the 2-year OS rate was 74%. The extent of liver metastatic disease correlated with a worse PFS (P = .01 by log-rank test) and a worse OS (P < .0001 by log-rank test). Analyses showed that metastatic replacement of more than 75% of the liver and prior chemotherapy were independently associated with inferior PFS.

CONCLUSION

Patients with locally advanced or metastatic PEC who are treated with FAS may have a reasonable RR, and responders may experience longer PFS and OS. The volume of metastases in the liver is the most important predictor of outcome.

Feasibility of somatostatin receptor scintigraphy in the detection of occult primary gastro-entero-pancreatic (GEP) neuroendocrine tumours

The aim of this study was to assess the feasibility of somatostatin receptor scintigraphy (SRS) for the detection of the site of unknown primary neuroendocrine neoplasms in patients in whom clinical examination and conventional radiological imaging had failed to do so. From 1996 to 2000, 36 patients were referred with gastro-entero-pancreatic (GEP) neuroendocrine tumours. In these patients, no clinical, radiological or endoscopic diagnostic modalities had been able to identify the primary tumour. Twenty-nine patients had liver metastases. Of the others, one had skin and one had lymph node metastases, three had diffuse metastatic involvement and two had carcinoid syndrome. SRS was carried out with both whole-body and single-photon emission tomography (SPET) acquisition, 24 and 48 h after the intravenous administration of In-pentetreotide. SRS findings were suggestive of the possible site of the primary lesion in 14 patients (39%). Six patients underwent surgery on the basis of the SRS findings and, therefore, the final, i.e. pathological, diagnosis was reached. In two patients, the final diagnosis was obtained within 6 months of SRS by means of a follow-up computed tomography (CT) scan. In the remaining six patients, the final diagnosis was reached after at least 2 years of follow-up by means of clinical, radiological and/or nuclear medicine findings. In all eight patients, the primary site identified during follow-up was consistent with the SRS findings. It can be concluded that SRS modified management in the six patients who had surgery. However, the most important finding was that SRS prompted surgical management in 17% of cases.

A phase II study of docetaxel in patients with metastatic carcinoid tumors

Twenty-one patients with metastatic carcinoid tumors were treated with docetaxel. Although the treatment was well tolerated, no objective radiologic responses were observed. Novel, more effective agents are needed for this disease.

BACKGROUND

Traditional combination chemotherapy regimens containing streptozocin, doxorubicin, and 5-fluorouracil have yielded disappointing results in patients with metastatic carcinoid tumors. The lack of efficacy of these combinations, together with their toxicity, has led to efforts to investigate therapeutic agents that are potentially more active and tolerable. We, therefore, assessed the efficacy of docetaxel in the treatment of patients with metastatic carcinoid tumors.

METHODS

Twenty-one patients with metastatic carcinoid tumors were treated with docetaxel, administered at a dose of 75 mg/m2 every three weeks. Patients were followed for evidence of toxicity, response, and survival.

RESULTS

Docetaxel was well tolerated in this patient population. However, no objective radiologic responses were noted in any of the 21 patients. Of the 13 patients who were evaluable for biochemical responses to therapy, four (31%) experienced decreases in 24-hour urinary 5-hydroxyindole acetic acid (5HIAA) excretion of greater than 50%. The clinical course of the patients enrolled in this study was marked by a high incidence of radiologically stable disease (81%), a median progression-free survival time of 10 months, and a median overall survival time of 24 months.

CONCLUSION

Although treatment with docetaxel results in biochemical responses in patients with metastatic carcinoid tumors, the lack of more significant antitumor activity demonstrates the need for novel, more effective agents in this disease.

Phase II study of interferon gamma in malignant carcinoid tumors (E9292): a trial of the Eastern Cooperative Oncology Group

PURPOSE

To determine the safety and efficacy of treatment with gamma interferon (IFNgamma) in patients with metastatic carcinoid tumor.

PATIENTS AND METHODS

51 patients were enrolled on this Phase II Eastern Cooperative Oncology Group (ECOG) study. Seventy five percent of them had hormonally active tumors. Treatment consisted of IFNgamma subcutaneously at a daily dose of 0.1 mg/m(2). Patents were evaluated for toxicity weekly for the first month and monthly thereafter; response was determined radiologically every 8 weeks.

RESULTS

Patients received treatment with IFNgamma for a median of 17.9 weeks (range 2-175). Toxicity was generally mild and expected: 61% experienced noninfected fever and 21% developed granulocytopenia. Three patients (6%) had a partial response; there were no complete responses. Median time to progression was 5.5 months (95% confidence interval 3.9-11.1). The 1-year progression free rate was 28% (13.4-43.4%). Median survival was 42 months, with a 1-year survival rate of 67% (53.3-80%).

DISCUSSION

This Phase II study demonstrated that therapy with IFNgamma in patients with metastatic carcinoid tumor was well-tolerated, but did not produce significant antitumor effects. The overall results were somewhat comparable to those previously seen with alpha interferons as well as cytotoxic drugs.

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.

Merkel cell carcinoma: report of seven cases

Merkel cell carcinoma (MCC) is an infrequent, highly malignant, primary skin tumor derived from neuroendocrine cells. Most MCCs occur in elderly individuals, on sun-exposed areas of the body, with the head and neck being the most common sites. We present 7 patients (2 male and 5 female, age 45-80 years) suffering from MCC and treated between 1993 and 2000. All tumors were located on the head and neck and varied from 0.9 to 2.3 cm in size. Five of the patients had stage II disease, 1 patient had stage Ia disease and 1 patient had stage III disease. Six of the patients had positive regional lymph nodes. All patients had local excision of the tumor. Six of them also had lymph node dissection and in 5 of them a superficial parotidectomy was performed. Five patients received adjuvant radiotherapy and 3 of them also received chemotherapy. Local and cervical lymph node recurrence was observed in only 1 patient. Metastases occurred in 5 patients. One patient died within 10 days for other reasons. The patient with the stage III tumor had a survival of 7 months. The other 5 patients had survivals varying from 15 to 54 months. MCC is a skin tumor with very poor prognosis and high recurrence and metastatic rates. Its treatment is still under discussion. Radical excision of the tumor is the main method of treatment. Selective lymph node dissection is suggested. Superficial parotidectomy seems necessary, especially if the tumor is on the auricle. Adjuvant radio- and chemotherapy may extend survival in case of small-size tumors.

Management of neuroendocrine liver metastases

BACKGROUND

The optimum management of neuroendocrine liver metastases, particularly the role of liver transplantation is ill-defined. Current strategies are based on anecdotal reports and small retrospective studies, rather than prospective data. This, as well as the failure to standardize treatment, has probably contributed to the reported variations in outcome.

DATA SOURCES

To formulate a putative management protocol and to reevaluate the role of liver transplantation in patients with neuroendocrine liver metastases, a review of the published literature (Medline search) was conducted.

CONCLUSIONS

Isolated hepatic metastases should be resected when suitable. Chemoembolization of liver metastases should precede resection of bulky disease and be used to palliate those with unresectable disease. Radiofrequency ablation is suitable for smaller metastatic lesions (<3 cm diameter) in the liver. Systemic treatment with somatostatin analogues or radioactive metaiodobenzylguanidine (MIBG) is appropriate to reduce symptoms and slow disease progression, but prospective data is required to define their exact roles as adjuvant and therapeutic agents. Although current systemic chemotherapy, applied in isolation, may have a role in patients in whom other therapies have failed, its efficacy remains unproven. Restriction of liver transplantation to the treatment of patients with carcinoid metastases with biologically favorable features, limited tumor bulk and without systemic disease may make transplantation a curative rather than a palliative treatment option in selected patients.

Peptide receptors as molecular targets for cancer diagnosis and therapy

During the past decade, proof of the principle that peptide receptors can be used successfully for in vivo targeting of human cancers has been provided. The molecular basis for targeting rests on the in vitro observation that peptide receptors can be expressed in large quantities in certain tumors. The clinical impact is at the diagnostic level: in vivo receptor scintigraphy uses radiolabeled peptides for the localization of tumors and their metastases. It is also at the therapeutic level: peptide receptor radiotherapy of tumors emerges as a serious treatment option. Peptides linked to cytotoxic agents are also considered for therapeutic applications. The use of nonradiolabeled, noncytotoxic peptide analogs for long-term antiproliferative treatment of tumors appears promising for only a few tumor types, whereas the symptomatic treatment of neuroendocrine tumors by somatostatin analogs is clearly successful. The present review summarizes and critically evaluates the in vitro data on peptide and peptide receptor expression in human cancers. These data are considered to be the molecular basis for peptide receptor targeting of tumors. The paradigmatic peptide somatostatin and its receptors are extensively reviewed in the light of in vivo targeting of neuroendocrine tumors. The role of the more recently described targeting peptides vasoactive intestinal peptide, gastrin-releasing peptide, and cholecystokinin/gastrin is discussed. Other emerging and promising peptides and their respective receptors, including neurotensin, substance P, and neuropeptide Y, are introduced. This information relates to established and potential clinical applications in oncology.

Immunohistochemical staining of cytologic smears with MIB-1 helps distinguish low-grade from high-grade neuroendocrine neoplasms

Neuroendocrine neoplasms (NENs) of the lung and gastrointestinal tract constitute a pathologic and biologic spectrum of tumors. Accurate cytologic diagnosis of a neuroendocrine neoplasm is important since definitive treatment frequently is based on low- and high-grade categories without histologic sampling. In many instances, however, low- and high-grade NENs share cytologic features, hindering a precise classification. Since the histologic diagnostic criteria for separation of low- from high-grade categories can be based on the proliferation rate, we proposed to evaluate the usefulness of the immunocytochemical stain for the proliferation marker MIB-1 in the grading of NENs. Cytologic preparations of 63 NENs were retrieved from the files of Memorial Sloan-Kettering Cancer Center, New York, NY. One representative alcohol-fixed slide from each case was destained and restained immunocytochemically for MIB-1. When MIB-1 immunoreactivity was considered, all low-grade NENs showed immunoreactivity in fewer than 25% of the neoplastic cells, and all high-grade NENs demonstrated immunoreactivity in more than 50% of neoplastic cells. Our study demonstrates that MIB-1 dramatically stratifies NENs as low-grade or high-grade. Therefore, the proliferation index also correlates with grade of NEN in cytology specimens.

Somatostatin analog therapy in treatment of gastrointestinal disorders and tumors

Long-acting octapeptide somatostatin analogs can effectively control symptoms resulting from excessive hormone release in patients with endocrine tumors of the gastrointestinal tract, provided that these tumors and metastases show a high expression of the somatostatin receptor subtype 2. The presence of this receptor subtype on these tumors can be demonstrated by in vitro studies, but also in vivo using 111In-pentetreotide scintigraphy. In a few studies, significant antiproliferative effects of these drugs on these tumors have also been demonstrated. The effectiveness of octapeptide somatostatin analogs in the management of chemotherapy- related and AIDS-related diarrhea and in reducing postoperative complications of pancreatic surgery have also been demonstrated. These drugs have been used to decrease the output of enterocutaneous pancreatic fistulas and are prophylactically used to prevent the development of these fistulas. Octapeptide somatostatin analog therapy is widely accepted for the initial management of acute variceal bleeding in cirrhotic patients. These drugs are currently also being evaluated for the treatment of advanced hepatocellular carcinoma and malignant intestinal obstruction. Radiotherapy with octapeptide somatostatin analogs coupled to radionuclides such as indium-111, yttrium-90, and lutetium- 177 is currently being studied in phase I-III trials.

Octreotide-sensitive ectopic ACTH production by islet cell carcinoma with multiple liver metastases

We report a 21-year-old woman with ectopic ACTH syndrome due to islet cell carcinoma with multiple liver metastases. On admission, she showed Cushingoid appearance (moon face, central obesity etc.) and had acute respiratory distress syndrome due to pneumocystis carinii pneumonia. Laboratory examination revealed marked elevations of plasma ACTH (735 pg/ml) and cortisol (145 microg/dl) with a profound hypokalemia (2.0 mEq/l). She was found to have multiple masses in the liver and a solid mass in the tail of pancreas by abdominal computerized tomography scanning. Treatment with octreotide successfully reduced elevated plasma ACTH and cortisol levels, and she received frequent transhepatic arterial embolization and chemotherapy. The primary pancreatic tumor was surgically removed, revealing islet cell carcinoma which contained high content of ACTH (100 microg/g wet weight) and abundantly expressed proopiomelanocortin and somatostatin receptor subtype-2 mRNAs as determined by Northern blot analysis. Postoperatively, she was free from symptoms for almost one year. However, progressive enlargement of multiple liver metastases refractory to chemotherapy led her to decide on total hepatectomy and liver transplantation from her father. After liver transplantation, she remained almost free from symptoms for almost one year. However, metastases developed to the mediastinal and paraaortic lymph nodes as detected by 111[In] pentetreotide scintigraphy. Eleven months after liver transplantation, she was again treated with octreotide and, 16 months after, with metyrapone, both of which were effective in reducing ACTH and cortisol levels, respectively, until she died of acute respiratory failure. This case of a young female patient with ectopic ACTH-producing islet cell carcinoma of the pancreas was quite unique in that she survived for 5 years despite the acute onset and rapid progression of the multiple liver metastases at least in part due to the long-lasting favorable response to octreotide and living-related liver transplantation.

Octreotide for palliative treatment of hepatic metastases from non-neuroendocrine primary tumours: evaluation of quality of life using the EORTC QLQ-C30 questionnaire

BACKGROUND AND AIM

While octreotide has been used in palliative treatment of hepatocellular carcinoma and neuroendocrine tumours with good results, little is known about the possible role of this in palliative treatment of hepatic metastases.

MATERIAL AND METHODS

We present our experience from the use of octreotide in palliative treatment of symptomatic liver metastases in 16 patients (11 males, five females, age ranged 43-69 years) with proven hepatic metastases from different primary tumours (six with non-small lung cancer, four with colon carcinoma, two with primary pancreatic head carcinoma, two with prostate cancer and two with adenocarcinoma of the stomach). All patients were administered 20 mg long-acting octreotide IM (octreotide LAR) once the first day, octreotide SC 0.5 mg three times daily on days 2-14 and then 20 mg long-acting octreotide IM every month. Quality of life was assessed by using the European Organization for Research and Treatment of Cancer (EORTC) Core Quality of Life Questionnaire (QLQ-C30). Tumour response was evaluated by using ultrasonography.

RESULTS

One month after baseline, octreotide resulted in significant (P < 0.01, Wilcoxon test) improvement and stabilization of all major related EORTC QLQ-C30 parameters such as global quality of life, pain, fatigue, insomnia, appetite loss as well as physical, emotional, cognitive, social and role functioning. Except for mild hyperglycaemia in six out of 16 patients and mild gastrointestinal complications in one patient, no other severe side effect due to octreotide was reported. Two patients died two months after the initiation of the study due to generalized metastatic disease, while the remaining 14 patients were still alive seven months after the initiation of the study. The hepatic metastases were stabilized and no new lesions were detected by ultrasonography.

CONCLUSIONS

Although further studies are warranted, we consider the use of octreotide a good alternative in palliative treatment of symptomatic liver metastases in patients with end-stage malignant disease.

Factors associated with progression of carcinoid heart disease

BACKGROUND

By releasing vasoactive substances into the circulation, carcinoid tumors can cause right-sided valvular heart disease. Factors associated with the progression of carcinoid heart disease are poorly understood. We conducted a retrospective study to identify such factors.

METHODS

Our sample included 71 patients with the carcinoid syndrome who underwent serial echocardiographic studies performed more than one year apart and 32 patients referred directly for surgical intervention after an initial echocardiographic evaluation. A score for carcinoid heart disease was determined on the basis of an assessment of valvular anatomy and function and the function of the right ventricle. An increase of more than 25 percent in the score between studies was considered suggestive of disease progression. Tumor progression was assessed on the basis of abdominal computed tomographic scans and changes in the level of urinary 5-hydroxyindoleacetic acid (5-HIAA), a metabolite of serotonin.

RESULTS

Of the patients with serial echocardiographic studies, 25 (35 percent) had an increase of more than 25 percent in the cardiac score. As compared with patients whose score changed by 25 percent or less, these patients had higher urinary peak 5-HIAA levels (median, 265 mg per 24 hours [interquartile range, 209 to 593] vs. 189 mg per 24 hours [interquartile range, 75 to 286]; P=0.004) and were more likely to have biochemical progression (10 of 25 patients vs. 9 of 46, P=0.05) and to have received chemotherapy (13 of 25 vs. 10 of 46, P=0.009). Logistic-regression analysis showed that a higher peak urinary 5-HIAA level and previous chemotherapy were predictors of an increase in the cardiac score that exceeded 25 percent (odds ratio for each increase in 5-HIAA of 25 mg per 24 hours, 1.08 [95 percent confidence interval, 1.03 to 1.13]; P=0.009); odds ratio associated with chemotherapy, 3.65 [95 percent confidence interval, 1.74 to 7.48]; P=0.001).

CONCLUSIONS

Serotonin is related to the progression of carcinoid heart disease, and the risk of progressive heart disease is higher in patients who receive chemotherapy than in those who do not.

Merkel cell carcinoma--a retrospective analysis of 17 cases

OBJECTIVE

To report clinical experience with the rare neuroendocrine Merkel cell carcinoma of the skin.

SUBJECTS AND SETTING

Seventeen patients with Merkel cell carcinoma of the skin treated at the Departments of Dermatology and ENT, Krankenhaus Dresden-Friedrichstadt, Dresden, Germany, during the years 1984-2000 were evaluated.

METHODS

A retrospective analysis was performed. Age and sex distribution, clinical data and therapy were collected. Outcome measures including overall survival, tumour-free survival and relapse-free survival were determined.

RESULTS

Six male and 11 female patients with an age range of 68-90 years (mean age 73.3 years) were identified. The primary tumour localization was head and neck region (n = 8), upper limbs (8), lower limbs (1). Twelve patients presented in tumour stage I, three in stage II and one in stage III. First line therapy was complete surgical excision with wide margins in 16 patients followed by loco-regional radiation in 12 of 16 cases. In 16 patients follow up data were available. After primary treatment complete response was achieved in 14 of 16 patients (87.5%), two patients had a partial response. The median of relapse-free survival was 44 weeks [mean +/- standard deviation: (44 +/- 118) weeks]. The median of overall survival was 102 weeks [mean +/- standard deviation: (137 +/- 94) weeks]. Three patients with a PR after primary treatment had a median overall survival of only 48 weeks [mean +/- standard deviation: (51 +/- 20) weeks].

CONCLUSIONS

Primary surgical treatment with wide excision combined with radiotherapy seems to be a reasonable first-line treatment but prospective controlled multicentre trials are necessary for validation.

Use of octreotide and lanreotide in the treatment of symptomatic non-resectable carcinoid tumours

BACKGROUND

Carcinoid tumours are rare neoplasms that secrete hormones and biogenic amines, most commonly serotonin. Octreotide and long acting lanreotide are found to be useful in the management of carcinoid syndrome by its interaction with somatostatin receptor, found on the carcinoid tumour. The aim of this study is to look at the efficacy of octreotide and long acting lanreotide in the treatment of symptomatic non-resectable carcinoid tumours.

METHOD

The effects of octreotide and long-acting lanreotide were studied in 10 patients with symptomatic non-resectable carcinoid tumours.

RESULTS

Symptom improvement occurred in nine of 10 patients. Three patients responded only to octreotide, three patients responded to both octreotide and long-acting lanreotide and three patients only responded to long-acting lanreotide. Slight reductions in 24-h urine 5-hydroxyindoleacetic acid levels occurred in three of six patients but no patients were found to have objective tumour regression on computed tomography scan.

CONCLUSIONS

Octreotide and long-acting lanreotide are useful palliative treatments for the control of symptoms in patients with non-resectable carcinoid tumours but there is no evidence of tumour stasis.

Somatostatin analogs in the treatment of medullary thyroid carcinoma

The medical therapy for advanced or metastatic medullary thyroid carcinoma has not been fully established. Somatostatin analogs have been used with variable success in the therapy of a few patients with medullary thyroid carcinoma. In the present study, we evaluated the effects of somatostatin analog therapy on calcitonin (ct) and carcinoembryonic antigen in patients with advanced medullary thyroid carcinoma. Five patients (2 men and 3 women, aged 35-57 yr) with post-operative recurrent medullary thyroid carcinoma received somatostatin analog therapy for 12 weeks. All had been previously treated with total thyroidectomy and lymphadenectomy. Four of them showed positive uptake in (111)In-pentetreotide scanning. One patient was treated with sc octreotide (100 microg/8 h), 3 patients received im slow release lanreotide (30 mg/14 days), and a further one received im octreotide LAR (30 mg/28 days). Serum samples for ct and carcinoembryonic antigen were obtained at 0, 1, 2, 4, 8 and 12 weeks of therapy. Therapy was well-tolerated in general, with minimal side-effects. One patient died after the first month of therapy because of advanced disease. Another patient showed normalization of his ct and carcinoembryonic antigen concentrations at the second week of therapy, maintaining elevated values thereafter. No clinically relevant changes in serum concentrations of ct and carcinoembryonic antigen were observed in the rest of the patients. One patient with positive (111)In-pentetreotide scan, showed no uptake after somatostatin analog therapy. No significant decrease in the size of metastases was evident in the remaining patients. In conclusion, therapy with different formulations of octreotide and lanreotide does not seem to modify serum concentrations of ct and carcinoembryonic antigen in patients with recurrent medullary thyroid carcinoma.

Hepatic artery embolization for control of symptoms, octreotide requirements, and tumor progression in metastatic carcinoid tumors

Hepatic artery embolization (HAE) has been utilized for treatment of advanced hepatic carcinoid metastases, with promising symptom palliation and tumor control. Our institution employs transcatheter HAE using Lipiodol/Gelfoam for treatment of carcinoid hepatic metastases, and this report presents our experience with twenty-four patients, examining symptom control, quality-of-life, octreotide dependence, and tumor progression. Twenty-four (11 male, 13 female, mean age = 59.4 +/- 2.5 yr) patients with carcinoid and unresectable hepatic metastases, confirmed by urinary 5-hydroxyindole acetic acid (5-HIAA) measurement and biopsy, were treated with Lipiodol/Gelfoam HAE from 1993-2001. Median follow-up was 35.0 months. Before HAE, 14 patients (58.3%) had malignant carcinoid syndrome, with symptoms quantified using our previously reported Carcinoid Symptom Severity Score, and 13 patients (54.2%) required octreotide for symptom palliation. Following treatment, symptom severity, octreotide dose, and tumor response were measured. Asymptomatic patients did not develop symptoms or require following treatment. Hepatic metastases remained stable (n = 4) or decreased (n = 19) in 23 patients (95.8%). Mean pretreatment Symptom Severity Scores (3.8 +/- 0.2), decreased to 1.4 +/- 0.1 post-treatment (P < 0.00001), with 64.3% of patients becoming asymptomatic. Mean pretreatment octreotide dosages (679.6 +/- 73.0 microg/d), decreased to 262.9 +/- 92.7 microg/d (P = 0.0024) post-treatment, with 46.2% of patients discontinuing octreotide. There were no treatment-related serious complications or deaths. This study demonstrates that Lipiodol/Gelfoam HAE produces excellent control of malignant carcinoid syndrome, allowing patients to decrease or eliminate use of octreotide, while controlling hepatic tumor burden.

Evaluation of (111)In-pentetreotide, (131)I-MIBG and bone scintigraphy in the detection and clinical management of bone metastases in carcinoid disease

Bone metastases are assumed to be rare in carcinoid disease and to be associated mainly with bronchial primaries. The aim of the present study was to evaluate the occurrence of bone metastases in patients with metastatic carcinoid tumours, and the role of various nuclear medicine modalities (bone scintigraphy, (111)In-pentetreotide and (131)I-MIBG) in its detection and clinical management. Nine (2 women, 7 men, median age 65 years) out of 86 consecutive carcinoid patients treated between 1987 and 1998 developed bone metastases (10%) with a median interval of 37 months between the diagnosis of metastatic carcinoid and bone metastases. Seven of them had non-bronchial primaries. (111)In-pentetreotide scintigraphy failed to detect the bone lesions in 50% of the cases, and (131)I-meta-iodobenzylguanidine(MIBG) scintigraphy in almost 80% of cases. Standard bone scintigraphy, however, was positive in all. Pain relief of bone metastases by means of radiation therapy was obtained in 5 of 6 patients. In another patient palliation of pain symptoms was obtained with Rhenium-186-hydroxyethylidene diphosphonate. Octreotide, Interferon of MIBG were ineffective for this purpose. It is concluded that bone metastases in carcinoid patients may be missed on (131)I-MIBG and (111)In-pentetreotide scintigraphy. Bone scintigraphy is a sensitive imaging technique. Diagnostic nuclear medicine modalities may be helpful in the clinical management of carcinoid disease.

Somatostatin analogues in the treatment of endocrine tumors of the gastrointestinal tract

Somatostatin and its long-acting analogues have been introduced for the treatment of endocrine tumours of the gastrointestinal tract as they have been shown to effectively control symptoms resulting from excessive hormone release in patients with carcinoid, Verner-Morrison and glucagonoma syndromes. This beneficial effect is due to the presence of somatostatin receptors in high densities on the majority of endocrine tumours. The symptomatic effect is less pronounced in insulinomas, since 30 - 50% of these tumours lack or express only a few somatostatin receptors. With respect to symptomatic control, somatostatin receptor subtypes 2 and 5 are the most important and the currently available long-acting analogues octreotide and lanreotide bind preferentially to these receptor subtypes. Long-term studies have shown that somatostatin analogues are safe and that the most important adverse advent is the development of gallstones. The antiproliferative potency of somatostatin and its analogues in vitro and in experimental tumour models prompted a number of studies in patients with metastatic endocrine tumours that are generally unresponsive to conventional chemotherapeutic protocols. Stabilisation of tumour growth lasting for months to a few years was the most favourable result, occurring in 30 - 70% of patients. However, definite proof of antiproliferative potency in man is still pending since placebo-controlled studies are not available. Radioligand therapy based on 111Indium, 90Yttrium and 177Lutetium coupled to somatostatin analogues via bifunctional chelators is currently under investigation with promising data concerning long-lasting control of symptoms and tumour growth from Phase I trials.