Radiation therapy in the management of patients with malignant carcinoid tumors

Early-Stage Primary Lung Neuroendocrine Tumors Treated With Stereotactic Body Radiation Therapy: A Multi-Institution Experience

PURPOSE

Current guidelines recommend surgery as standard of care for primary lung neuroendocrine tumor (LNET). Given that LNET is a rare clinical entity, there is a lack of literature regarding treatment of LNET with stereotactic body radiation therapy (SBRT). We hypothesized that SBRT could lead to effective locoregional tumor control and long-term outcomes.

METHODS AND MATERIALS

We retrospectively reviewed 48 tumors in 46 patients from 11 institutions with a histologically confirmed diagnosis of LNET, treated with primary radiation therapy. Data were collected for patients treated nonoperatively with primary radiation therapy between 2006 and 2020. Patient records were reviewed for lesion characteristics and clinical risk factors. Kaplan-Meier analysis, log-rank tests, and Cox multivariate models were used to compare outcomes.

RESULTS

Median age at treatment was 71 years and mean tumor size was 2 cm. Thirty-two lesions were typical carcinoid histology, 7 were atypical, and 9 were indeterminate. The most common SBRT fractionation schedule was 50 to 60 Gy in 5 daily fractions. Overall survival at 3, 6, and 9 years was 64%, 43%, and 26%, respectively. Progression-free survival at 3, 6, and 9 years was 88%, 78%, and 78%, respectively. Local control at 3, 6, and 9 years was 97%, 91%, and 91%, respectively. There was 1 regional recurrence in a paraesophageal lymph node. No grade 3 or higher toxicity was identified.

CONCLUSIONS

This is the largest series evaluating outcomes in patients with LNET treated with SBRT. This treatment is well tolerated, provides excellent locoregional control, and should be offered as an alternative to surgical resection for patients with early-stage LNET, particularly those who may not be ideal surgical candidates.

Adolescent Plaque Brachytherapy for Large Choroidal Metastasis from Lung Carcinoid Tumor

The purpose of this publication is to report a child with choroidal metastasis from a primary lung carcinoid tumor treated with 125-iodine plaque brachytherapy while achieving complete tumor regression. A 15-year-old girl with a history of stage IV lung carcinoid tumor developed painless progressive visual loss in her right eye. Ophthalmological exam documented a unilateral solitary large choroidal mass with complete exudative retinal detachment. Planned palliative treatment with plaque brachytherapy was performed utilizing a total dose of 45 Gy to the tumor apex. No tumor regression was noted after 6 months of follow-up. Ten months after primary therapy, re-treatment with a total dose of 90 Gy to the tumor apex was performed due to tumor progression. Complete regression was achieved after secondary treatment without evidence of recurrence after 18 months of follow-up. In conclusion, high-dose plaque brachytherapy may induce complete tumor regression in select adolescent patients with choroidal metastasis from lung carcinoid tumor.

Commonwealth Neuroendocrine Tumour Research Collaboration and the North American Neuroendocrine Tumor Society Guidelines for the Diagnosis and Management of Patients With Lung Neuroendocrine Tumors: An International Collaborative Endorsement and Update of the 2015 European Neuroendocrine Tumor Society Expert Consensus Guidelines

Lung neuroendocrine tumors (LNETs) are uncommon cancers, and there is a paucity of randomized evidence to guide practice. As a result, current guidelines from different neuroendocrine tumor societies vary considerably. There is a need to update and harmonize global consensus guidelines. This article reports the best practice guidelines produced by a collaboration between the Commonwealth Neuroendocrine Tumour Research Collaboration and the North American Neuroendocrine Tumor Society. We performed a formal endorsement and updating process of the 2015 European Neuroendocrine Tumor Society expert consensus article on LNET. A systematic review from January 2013 to October 2017 was conducted to procure the most recent evidence. The stepwise endorsement process involved experts from all major subspecialties, patients, and advocates. Guided by discussion of the most recent evidence, each statement from the European Neuroendocrine Tumor Society was either endorsed, modified, or removed. New consensus statements were added if appropriate. The search yielded 1109 new publications, of which 230 met the inclusion criteria. A total of 12 statements were endorsed, 22 statements were modified or updated, one was removed, and two were added. Critical answered questions for each topic in LNET were identified. Through the consensus process, guidelines for the management of patients with local and metastatic neuroendocrine tumors have been updated to include both recent evidence and practice changes relating to technological and definitional advances. The guidelines provide clear, evidence-based statements aimed at harmonizing the global approach to patients with LNETs, on the basis of the principles of person-centered and LNET-specific care. The importance of LNET-directed research and person-centered care throughout the diagnosis, treatment, and follow-up journey is emphasized along with directions for future collaborative research.

Current treatment strategies for patients with advanced gastroenteropancreatic neuroendocrine tumors (GEP-NETs)

Background

Neuroendocrine tumors (NETs) are rare neoplasms, with an estimated annual incidence of ~ 6.9/100,000. NETs arise throughout the body from cells of the diffuse endocrine system. More than half originate from endocrine cells of the gastrointestinal tract and the pancreas, thus being referred to as gastroenteropancreatic NETs (GEP NETs). The only treatment that offers a cure is surgery, however most patients are diagnosed with metastatic disease, and curative surgery is usually not an option.Since the majority of patients are not candidate for curative surgery, they can be offered long-term systemic treatment, for both symptomatic relief and tumor growth suppression. Evidence based treatment options include somatostatin analogues, everolimus (an mTOR inhibitor), sunitinib (a tyrosine kinase inhibitor), peptide receptor radionuclide therapy (PRRT), chemotherapy, etc., alone or combined with cytoreductive procedures (surgery or liver directed procedures). However, there is an increasing need for novel therapies. Other treatment options being investigated are immunotherapy and epigenetic assessment that may lead to more personalized interventions. Following first line therapy with somatostatin analogues, there is no clear information to date indicating a preferred treatment sequence, and therefore the treatment approach should be individualized based on each NET patient characteristics.

Conclusions

NET patients are increasingly diagnosed throughout the world, usually with metastatic disease and requiring systemic therapy. We believe that each patient should be therefore thoroughly evaluated and individually discussed by a multidisciplinary and dedicated NET-expert team, updated with all treatment options including ongoing clinical trials, and before selecting the proper treatment sequence.

External Beam Radiotherapy in the Treatment of Gastroenteropancreatic Neuroendocrine Tumours: A Systematic Review

AIMS

External beam radiotherapy (EBRT) is infrequently used to treat gastroenteropancreatic neuroendocrine tumours (GEPNETS), with little published data to date. We carried out a systematic review to assess the activity of EBRT for GEPNETS.

MATERIALS AND METHODS

Major databases were searched for papers including at least five patients treated with contemporary EBRT techniques. Eligible studies underwent dual independent review. The primary end points were response rate for lesions treated with definitive intent and recurrence-free survival for primary lesions treated with neoadjuvant or adjuvant intent.

RESULTS

Of 11 included studies (all retrospective), seven investigated pancreatic neuroendocrine tumours (PNETs, 100 patients, 14% grade 3) and four studies investigated extra-pancreatic neuroendocrine tumours (84 patients, 14% grade 3). Trials investigating PNETs administered a median of 50.4 Gy via three-dimensional conformal radiotherapy and intensity-modulated radiotherapy. EBRT was given with neoadjuvant or adjuvant intent in 56 patients, with a recurrence rate of 15%. For the 44 patients not undergoing surgery, the radiological response rate was 46%. Grade 3 + toxicity rates were 11% (acute) and 4% (late). Twelve patients with anorectal neuroendocrine carcinoma received 58 Gy to the primary tumour. Seventy-two patients were treated to sites of metastatic disease (34 bone, 27 brain, 11 soft tissue). Local and distant control were poorly reported. Overall survival ranged from 9 to 19 months. No studies in this group reported toxicity outcomes.

CONCLUSIONS

There are limited, retrospective data on the overall activity and safety of EBRT in GEPNETS. EBRT generally seems to be well tolerated in selected PNET patients with encouraging activity. Well-designed prospective studies in clearly defined populations are required to clarify the role of EBRT in neuroendocrine tumours.

Incidental Primary Intradural Carcinoid Tumor in a Patient with Lumbar Radiculopathy

BACKGROUND

Carcinoid tumors are neuroendocrine neoplasms derived from enterochromaffin cells. Central nervous system involvement is rare. The reported cases include metastases to brain or spinal cord, and primary skeletal or extradural disease resulting in compressive myeloradiculopathy. There are 2 previously reported cases of primary intradural extramedullary carcinoid tumor, presenting with compressive symptoms. We report the first case of primary incidental intradural extramedullary carcinoid tumor.

CASE DESCRIPTION

A 68-year-old man was complaining of a 2-month history of left-sided back pain and sciatica; however, he presented with acutely worse symptoms of severe left sciatica. There was no sphincter dysfunction nor power deficit on examination. A magnetic resonance imaging (MRI) scan of the lumbar spine revealed an L4-5 central disk protrusion causing left L5 nerve root compression, and a heterogeneous enhancing intradural mass at the L2-3 level displacing the cauda equina. An L4-5 microdiscectomy followed by an L2-3 laminectomy and resection of the intradural mass was performed. There was a postoperative left S1 paresthesia that was managed medically; however, the postoperative period was unremarkable. A postoperative MRI of the lumbar spine showed complete resection of the mass. A staging scan revealed an incidental thyroid nodule; however, there was no other disease burden. Histopathology of the resected specimen revealed a primary spinal carcinoid tumor.

CONCLUSIONS

To our knowledge, this is the first reported case of incidental primary intradural spinal carcinoid tumor. Even though intradural spinal carcinoid tumors are exceedingly rare, they should be included in the differential diagnosis of enhancing intradural lesions.

Radioembolization with yttrium-90 resin microspheres for neuroendocrine tumor liver metastases

PURPOSE

We aimed to evaluate the effectiveness and safety of radioembolization with yttrium-90 (90Y) microspheres in cases with unresectable neuroendocrine tumor liver metastases (NETLMs).

METHODS

Thirty patients (mean age, 55 years) underwent resin-based 90Y radioembolization for unresectable NETLM at a single institution between April 2008 and June 2013. Post-treatment tumor response was assessed by cross-sectional imaging using the Response Evaluation Criteria in Solid Tumors (RECIST). Prognostic variables that affected survival were determined.

RESULTS

The mean follow-up was 23.0±19.4 months and the median overall survival was 39 months (95% CI, 12.6-65.4 months), with one- and two-year survival rates of 71% and 45%, respectively. Imaging follow-up using RECIST at three-month intervals demonstrated partial response in 43%, complete remission in 3%, stable disease in 37%, and progressive disease in 17% of patients. Extent of tumor involvement was found to have a statistically significant influence on overall survival (P = 0.03). The existence of extrahepatic disease at the time of radioembolization, radiographic response, age, and primary neuroendocrine tumor site were not significant prognostic factors.

CONCLUSION

The current study demonstrates the effectiveness and safety of radioembolization for the treatment of unresectable NETLMs. We identified that the extent of tumor involvement has a significant effect on overall survival. The use of imaging methods reflecting metabolic activity or cellularity such as scintigraphy or diffusion-weighted MRI would be more appropriate, for the response evaluation of liver metastases after radioembolization.

Bronchial and Thymic Carcinoid Tumors

Bronchial and thymic carcinoids are rare. We present epidemiologic data and potential risk factors. The approach to bronchial and thymic carcinoid patients is discussed, from the initial diagnosis and evaluations to treatment. These malignancies follow staging systems of their site of origin. Because bronchial and thymic carcinoids are rare, we use many treatment strategies that have been demonstrated in gastrointestinal and pancreatic neuroendocrine tumors. The lack of information regarding efficacy in bronchial and thymic carcinoids, as well as the scarcity of therapeutic options available, demands the importance of clinical trials that include these patients.

Malignant metastatic carcinoid presenting as brain tumor

Carcinoid tumors are rarely known to metastasise to the brain. It is even more rare for such patients to present with symptoms related to metastases as the initial and only symptom. We present a case of a 60-year-old man who presented with hemiparesis and imaging features suggestive of brain tumor. He underwent surgery and the histopathology revealed metastatic malignant lesion of neuroendocrine origin. A subsequent work up for the primary was negative. Patient was treated with adjuvant radiotherapy. We present this case to highlight the pathophysiological features, workup and treatment options of this rare disease and discuss the methods of differentiating it from more common brain tumors.

Overexpression of PY1289-HER3 in sporadic pulmonary carcinoid from patients bearing MEN1 gene variants

The present study aimed to investigate the expression of human epidermal growth factor receptors (HERs) (HER1/HER2/HER3/HER4) and their phosphorylated forms (p-HER1/p-HER2/p-HER3/p-HER4) in pulmonary carcinoids (PCs). HER and p-HER protein expression was assessed by immunohistochemistry on tissue microarrays in 37 specimens of sporadic PCs, 29 typical carcinoids (TCs) and 8 atypical carcinoids (ACs). When compared with the ACs, the TCs did not exhibit any differences in terms of HER/p-HER expression. The tumors of this study have previously been characterized for the expression of menin and the mutational status of menin 1 (MEN1), a gene strongly implicated in the pathogenesis of PCs. In the present study, it was found that the cytoplasmic (‘disarrayed’), but not nuclear (‘arrayed’) expression of menin was positively correlated with HER3 (P=0.004), HER4 (P=0.015), p-HER1 (P=0.005), p-HER3 (P<0.001), and p-HER4 (P=0.001) expression. Moreover, HER3 and p-HER3 were found to be significantly more expressed in PCs with MEN1 variants, than in tumors with MEN1 wild-type (P=0.000 and P=0.025, respectively). These findings suggest the potential clinical use of HER inhibitors in the treatment of patients with PCs, particularly for individuals with p-HER3-positive PCs harboring MEN1 gene variants.

The Management for Intracranial Metastatic Neuroendocrine Tumor With Lung Origin

Neuroendocrine tumor (NET) is not a common source of brain metastasis and the standard management of intracranial metastatic NET with lung origin remains unclear as a result of its rarity. We aimed to generalize some applicable protocols from our current 2 cases and relevant literature.

Beyond adenocarcinoma: current treatments and future directions for squamous, small cell, and rare lung cancer histologies

Lung cancer encompasses a diverse spectrum of histologic subtypes. Until recently, the majority of therapeutic advances were limited to the minority of patients with adenocarcinoma. With the advent of comprehensive genomic profiling of squamous and small cell lung cancers, new therapeutic targets have emerged. For squamous tumors, the most promising of these include fibroblast growth factor receptor (FGFR), the phosphatidylinositol 3-kinase (PI3K) pathway, discoidin domain receptor 2 (DDR2), and G1/S checkpoint regulators. In 2014, the antiangiogenic agent ramucirumab was approved for all non-small cell lung cancer (NSCLC) histologies, including squamous tumors. Immunotherapeutic approaches also appear to be promising for these cases. Genomic analysis of small cell lung cancer has revealed a high mutation burden, but relatively few druggable driver oncogenic alterations. Current treatment strategies under investigation are focusing on targeting mitotic, cell cycle, and DNA repair regulation, as well as immunotherapy. Pulmonary neuroendocrine tumors represent a diverse spectrum of diseases that may be treated with somatostatin analogs, cytotoxic agents, and molecularly targeted therapies. Radiolabeled somatostatin analogs and combinations with mammalian target of rapamycin (mTOR) inhibitors also show potential. Large cell neuroendocrine tumors share numerous clinical, pathologic, and molecular features with small cell lung cancer; however, whether they should be treated similarly or according to a NSCLC paradigm remains a matter of debate.

Divergent management strategies for typical versus atypical carcinoid tumors of the thoracic cavity

OBJECTIVES

At our institution, limited surgical techniques are reserved only for suspected typical carcinoids, and nodal dissection and multimodality therapy are frequently used for atypical carcinoids. We describe the results of these differing management strategies based on initial clinicopathologic characteristics.

METHODS

Retrospective review of patients treated for thoracic carcinoid from 1995 to 2009. Information was abstracted concerning surgical and nonsurgical treatments, pathology results, and outcomes. Event-free and survival endpoints were compared.

RESULTS

The median follow-up was 5.0 years (range, 0.5 to 17.4 y). Fifty-two patients underwent resection. The 5-year event-free survival for typical carcinoid patients was 88.2%. Atypical carcinoids had a tendency for nodal involvement (50% vs. 15%) and greater likelihood for disease recurrence, with a 5-year event-free survival of 50%.

CONCLUSIONS

These data support the appropriateness of divergent management strategies for typical versus atypical bronchial carcinoids. We propose the following: (1) nonanatomic resection is acceptable only for peripheral typical carcinoids; (2) extended mediastinal dissection should be limited to central presentations, clinically aggressive, or atypical carcinoids; (3) atypical histology, especially with nodal involvement, is prognostic for recurrence and metastasis; (4) nonsurgical therapies only rarely achieve long-term freedom from disease.

Brain carcinoid metastases: outcomes and prognostic factors

OBJECT

Carcinoid tumors are rare and have generally been regarded as indolent neoplasms. Systemic disease is often incurable; however, patients may live years with this disease. Furthermore, metastatic brain lesions are extremely uncommon. As such, few series have examined outcomes and prognostic factors in those with brain involvement.

METHODS

The authors performed a retrospective review of patients who underwent primary treatment at Mayo Clinic in Rochester, Minnesota, for metastatic carcinoid tumors to the brain between 1986 and 2011. Progression-free survival (PFS) and overall survival (OS) were analyzed using Kaplan-Meier statistics. Cox proportional hazards were used to determine predictors of survival.

RESULTS

Fifteen patients underwent primary treatment for metastatic carcinoid tumors to the brain between 1986 and 2011. Their mean age was 58 ± 12 years. Eighty percent (n = 12) of patients underwent surgery, whereas 2 received stereotactic radiosurgery and 1 had whole-brain radiation therapy (WBRT) as the primary treatment. The median follow-up duration was 19 months (maximum 124 months). Systemic disease progression occurred in 73% and was the leading cause of death in known cases, while intracranial disease recurred in 40%. The median PFS and OS were 21 and 19 months, respectively. The use of adjuvant WBRT correlated with improved PFS (HR 0.15, CI 0.0074-0.95, p = 0.044). Those who underwent surgery as primary modalities trended toward longer progression-free intervals (p = 0.095), although this did not reach significance.

CONCLUSIONS

Metastatic carcinoid disease to the brain appears to have a worse prognosis than that of other extracranial metastases. Although there was a trend toward a survival advantage in patients who underwent surgery and WBRT, further study is needed to establish definitive treatment recommendations.

Radionuclide therapy via SSTR: future aspects from experimental animal studies

There is need for better therapeutic options for neuroendocrine tumours. The aim of this review was to summarize results of experimental animal studies and raise ideas for future radionuclide therapy based on high expression of somatostatin (SS) receptors by many neuroendocrine tumours. In summary, one of the major options is individualized treatment for each patient, including choice of SS analogues, radionuclides and treatment schedules. Other options are methods to increase the treatment effect on tumour tissue (increasing tumour uptake and retention by upregulation of receptor expression and avoiding saturation of receptor binding), methods to increase the tumour tissue response (by choice of radionuclides, SS analogues or combined therapies), and methods to reduce side effects (diminished uptake and retention in critical organs and reduced normal tissue response). Furthermore, combination therapy with other radiopharmaceuticals, cytotoxic drugs or radiosensitizers can be considered to enhance the effects of radiolabelled SS analogues.

Radioembolization of symptomatic, unresectable neuroendocrine hepatic metastases using yttrium-90 microspheres

PURPOSE

To evaluate safety, efficacy, and symptom-control of radioembolization in patients with unresectable liver metastases from neuroendocrine tumors (NETLMs).

MATERIALS AND METHODS

Forty-two patients (mean age of 62 years) with treatment-refractory NETLMs underwent radioembolization using yttrium-90 ((90)Y) resin microspheres. Posttreatment tumor response was assessed by cross-sectional imaging using the Response Evaluation Criteria in Solid Tumors (RECIST) and tumor-marker levels. Laboratory and clinical toxicities and clinical symptoms were monitored.

RESULTS

The median activity delivered was 1.63 GBq (range 0.63-2.36). Imaging follow-up using RECIST at 3-month follow-up demonstrated partial response, stable disease, and progressive disease in 22.5, 75.0, and 2.5% of patients, respectively. In 97.5% of patients, the liver lesions appeared hypovascular or partially necrotic. The mean follow-up was 16.2 months with 40 patients (95.2%) remaining alive. The median decrease in tumor-marker levels at 3 months was 54.8% (chromogranin A) and 37.3% (serotonin), respectively. There were no acute or delayed toxicities greater than grade 2 according to Common Terminology Criteria for Adverse Events [CTCAE (v3.0)]. No radiation-induced liver disease was noted. Improvement of clinical symptoms 3 months after treatment was observed in 36 of 38 symptomatic patients.

CONCLUSION

Radioembolization with (90)Y-microspheres is a safe and effective treatment option in patients with otherwise treatment-refractory NETLMs. Antitumoral effect is supported by good local tumor control, decreased tumor-marker levels, and improved clinical symptoms. Further investigation is warranted to define the role of radioembolization in the treatment paradigm for NETLMs.

Pulmonary neuroendocrine/carcinoid tumors: a review article

Neuroendocrine tumors are a unique malignant neoplasm that can arise from the respiratory tree. Although well-differentiated bronchial neuroendocrine tumors (also called carcinoid tumors) are reported to account for approximately 25% of all neuroendocrine tumors, they represent only 1% to 2% of all lung cancers. The epidemiology, clinical behavior, and treatment of neuroendocrine carcinoid tumors differ significantly from other lung malignancies. In this article, the recent data regarding these tumors were reviewed with attention to the treatment modalities used. Although conventional cytotoxic therapy has not been reported to demonstrate much promise in this entity over the past 4 decades, newer molecular targeted agents including those that targeted angiogenesis and the mammalian target of rapamycin (mTOR) pathway have shown encouraging results in early phase trials for advanced carcinoid tumors.

Analysis of ErbB receptors in pulmonary carcinoid tumors

PURPOSE

This study aimed to investigate the expression of the ErbB family of receptor tyrosine kinases in pulmonary typical carcinoid and atypical carcinoid tumors and to understand the role of epidermal growth factor receptor (EGFR) signaling in pulmonary carcinoid tumor proliferation.

EXPERIMENTAL DESIGN

Surgically resected typical carcinoid (n = 24) and atypical carcinoid (n = 7) tumor tissues were analyzed by immunohistochemical staining for EGFR, ErbB2, ErbB3, and ErbB4. Sequencing of tumor DNA of exons 18 to 21 of the EGFR gene and the KRAS gene was carried out. Biochemical analysis of lung carcinoid cell lines was used to investigate EGFR signal transduction and response to erlotinib inhibition.

RESULTS

The analysis showed that 45.8% of typical carcinoid and 28.6% of atypical carcinoid tumors express EGFR, 100% of the tumors lack expression of ErbB2, and 100% have moderate to intense staining for ErbB3 and ErbB4. Sequencing of tumor DNA of exons 18 to 21 of the EGFR gene revealed the absence of tyrosine kinase domain mutations in these tumors. Instead, 80.6% tumors harbored a synonymous single nucleotide polymorphism in exon 20. Because EGFR and KRAS mutations tend not to be present at the same time, we sequenced the KRAS gene from pulmonary carcinoid tumor DNA and found that 100% were wild-type. Using a lung carcinoid cell line that expresses EGFR, we found that erlotinib reduced proliferation by inhibiting EGFR signal transduction.

CONCLUSIONS

Our findings suggest clinical potential for the use of EGFR inhibitors in the treatment of patients with pulmonary carcinoid tumors, particularly for patients with EGFR-positive pulmonary carcinoid tumors not amenable to surgical resection.

Radioembolization for unresectable neuroendocrine hepatic metastases using resin 90Y-microspheres: early results in 148 patients

PURPOSE

The use of 90Y-microspheres to treat unresectable liver metastases originating from a variety of neuroendocrine tumors was reviewed.

MATERIALS AND METHODS

This is a retrospective review from 10 institutions of patients given 90Y-microsphere therapy for neuroendocrine hepatic metastases. Physical, radiographic, biochemical, and clinical factors associated with treatment and response were examined. All patients were followed with laboratory and imaging studies at regular intervals until death, or censured whether other therapy was given after brachytherapy. Toxicities (acute and late) were recorded, and survival of the group determined.

RESULTS

A total of 148 patients were treated with 185 separate procedures. The median age was 58 years (26-95 years) at treatment with median performance status of Eastern Cooperative Oncology Group (0). The median activity delivered was 1.14 GBq (0.33-3.30 GBq) with a median of 99% of the planned activity able to be given (38.1%-147.4%). There were no acute or delayed toxicity of Common Terminology Criteria for Adverse Events v3.0 grade 3 in 67% of patients, with fatigue (6.5%) the most common side effect. Imaging response was stable in 22.7%, partial response in 60.5%, complete in 2.7% and progressive disease in 4.9%. No radiation liver failure occurred. The median survival is 70 months.

CONCLUSION

Radioembolization with 90Y-microspheres to the whole liver, or lobe with single or multiple fractions are safe and produce high response rates, even with extensive tumor replacement of normal liver and/or heavy pretreatment. The acute and delayed toxicity was very low without a treatment related grade 4 acute event or radiation induced liver disease in this modest-sized cohort. The significant objective response suggests that further investigation of this approach is warranted.

External beam irradiation of myocardial carcinoid metastases: a case report

The heart is an exceedingly rare site of metastatic involvement in carcinoid tumors. Only nineteen cases have been described in the literature over the past 30 years. We report here on a patient who presented with progressive carcinoid syndrome despite surgical resection of her liver metastases. She was found to have cardiac metastases on inidium-111-pentetreotide scintigraphy and subsequently underwent external beam radiation to the heart resulting in symptomatic palliation of her syndrome and objective radiographic response. To our knowledge, this is the first reported case of metastatic cardiac carcinoid treated with external beam irradiation.

Effective treatment of locally advanced endocrine tumors of the pancreas with chemoradiotherapy

BACKGROUND/AIMS

The use of chemoradiation in the management of locally advanced pancreatic endocrine tumors has not been reported in the medical literature. Patients with unresectable tumors are often included in trials of systemic chemotherapy, and use of external beam radiation has been only described in few case reports. Given the sensitivity of pancreatic endocrine tumors to cytotoxic agents including streptozocin, doxorubicin and 5-FU, we have hypothesized that the combination of concurrent and sequential chemotherapy and radiation will yield higher response rates than acheivable with chemotherapy alone.

METHODS

Six patients with locally advanced pancreatic endocrine tumors were treated with a protocol consisting of radiation concurrent with infusional 5-FU (or capecitabine) along with induction and consolidation chemotherapy (streptozocin and doxorubicin). We retrospectively determined the objective radiographic response rate.

RESULTS

The objective response rate was 80%. With a median follow-up of 29 months, all six patients in the study have had continued reduction in tumor size from the time of the first posttreatment scan to the most recent scan. None of the patients have experienced local or metastatic disease progression. Treatment was well tolerated with minimal toxicity.

CONCLUSION

The combination of concurrent and sequential chemoradiotherapy appears to be a highly effective treatment for locally advanced pancreatic endocrine tumors.

Well-Differentiated Neuroendocrine Carcinomas: The Spectrum of Histologic Subtypes and Various Clinical Behaviors

The term "well-differentiated neuroendocrine carcinoma" was coined to describe a variety of demonstrably neuroendocrine tumors which were more aggressive (both with respect to their histologic appearance and their clinical course) than (typical) bronchial carcinoids but were also clearly distinguishable from small cell neuroendocrine carcinomas. This umbrella term encompasses a variety of tumors previously described by a variety of terms including "atypical" carcinoids, "malignant tumorlets," peripheral stage I small-cell carcinoma, as well as neoplasms described simply as "undifferentiated carcinoma" (prior to the recognition of their neuroendocrine properties). As such, this term is a broad term and is not simply synonymous with "atypical carcinoid." Over time, at least 3 subtypes have been identified based upon their histologic appearance and mitotic index, with correspondingly aggressive clinical courses.

Endocrine tumours of the hindgut

Neuroendocrine tumours of the colon and rectum are rare but distinct with regard to clinical symptoms, diagnostic and therapeutic management and prognosis compared to other neuroendocrine tumours of the gut as well as ordinary colorectal cancer. Therapeutic algorithms are proposed depending mainly on analogous TNM categories and grading considering conventional and experimental surgical and non-surgical therapy. Colonic neuroendocrine tumours are often misdiagnosed as undifferentiated adenocarcinoma and are therefore not properly treated with adjuvant and additive chemotherapy. As most rectal neuroendocrine tumours are benign because of submucosal extension only, the size and infiltration depth correlates with lymph-node and distant metastases and therefore with the prognosis. It is unknown whether endoscopic ultrasound can improve the diagnostic accuracy compared to size-related conclusions, and therefore whether it can change therapeutic strategies and improve survival by modern rectal surgery.

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.

Prospective study of thymic carcinoids in patients with multiple endocrine neoplasia type 1

Little is known of the natural history of thymic carcinoids in multiple endocrine neoplasia type 1 (MEN1). This is important because in 1993 they were identified as a frequent cause of death, yet only small retrospective studies and case reports exist. We report results of a prospective study of 85 patients with MEN1 evaluated for pancreatic endocrine tumors and followed over a mean of 8 yr with serial chest computed tomography, magnetic resonance imaging (MRI), chest x-ray, and, since 1994, octreoscans [somatostatin receptor scintigraphy (SRS)]. Seven patients (8%) developed thymic carcinoids. Patients with and without carcinoids did not differ in clinical, laboratory, or MEN1 tumor features, except for male gender and the presence of a gastric carcinoid. All thymic tumors were hormonally inactive. Four thymic carcinoids lacked 11q loss of heterozygosity, although it was found in three pancreatic endocrine tumors. Computed tomography and/or MRI were more sensitive than SRS or chest x-ray in detecting tumors initially or with recurrence. All patients underwent resection of the thymic carcinoid, and in all patients followed more than 1 yr, the tumor recurred. Bone metastases developed in two patients and were detected early only on MRI, not SRS. This study provides information on early thymic carcinoids and allows modifications of existing guidelines to be recommended for their diagnosis, surveillance, and treatment.

Outcomes and patterns of failure in bronchial carcinoid tumors

PURPOSE

To clarify the natural history, prognosis, and treatment failure patterns for bronchial carcinoid tumors according to their clinical and histopathologic features.

METHODS

The charts of 241 patients from our institution with bronchial carcinoid tumors were reviewed. Thirty-four patients had no follow-up, yielding a study population of 206. Of the 206 patients, 62 had atypical carcinoid (AC) and 144 had typical carcinoid (TC) tumors.

RESULTS

The 5-, 10-, and 20-year disease-specific survival rates were lower in patients with AC (60.1%, 36.8%, and 28.1%, respectively) than in those with TC (79.0%, 62.9%, and 38.8%, respectively; p = 0.0002). Predictors of poor outcome included more advanced stage (p <0.00001), male gender (p = 0.019), symptoms at presentation (p = 0.013), and age >or=60 years (p = 0.02). Stage I AC was associated with a median disease-free survival of 96 months compared with 222 months for Stage I TC (p = 0.0002) and had an actuarial 22% locoregional failure rate 5 years after surgery compared with 6% for Stage I TC (p = 0.022). The disease-free survival for Stage II and III AC was worse than that for Stage II or III TC, but the difference did not reach statistical significance (p = 0.15). Locoregional failure was also prominent in Stage II and III AC. Second malignancies were common in patients with bronchial carcinoids (56 of 206 patients).

CONCLUSION

Stage-for-stage, the outcome is worse for patients with AC than for those with TC. Locoregional failure is common after curative resection, even for early-stage AC. Second cancers are common in patients with carcinoid tumors.

Carcinoid tumour of the orbital muscles: A rare occurrence

Malignant carcinoid tumours are rare and usually follow an indolent course. Metastases from these tumours are uncommon, and usually involve bone, liver and lymph nodes. Orbital metastases have rarely been described, and generally involve the choroid rather than orbital structures. Our knowledge of the response of these tumours to radiotherapy is extremely limited. Two cases of orbital metastases treated with radiotherapy are presented here and the literature on the efficacy of palliative radiotherapy for this tumour is reviewed. Recommendations are made regarding an effective radiotherapy regimen for treating orbital metastases from malignant carcinoid tumours.

Typical and atypical pulmonary carcinoids : outcome in patients presenting with regional lymph node involvement

STUDY OBJECTIVE

Typical pulmonary carcinoid tumors are well-differentiated neuroendocrine tumors that are associated with good patient survival rates, while atypical carcinoid tumors are more aggressive and have worse patient survival rates. Because these tumors rarely involve the thoracic lymph nodes at presentation, it is currently unknown to what extent the presence of thoracic lymph node metastases at the time of diagnosis influences patient survival.

METHODS

A computerized search of the medical records for pulmonary carcinoid tumor at the Mayo Clinic from 1976 to 1997 revealed 517 patients, from which we identified 36 patients with pulmonary carcinoid tumors involving regional thoracic lymph nodes but without distant disease. For each patient, we reviewed the tumor histology, stage, and outcome. In addition, because the histologic criteria for the diagnosis of carcinoid tumors had changed significantly during the time of the study, we reexamined all of the histologic specimens using the current World Health Organization (WHO) criteria for classifying pulmonary neuroendocrine tumors.

RESULTS

After reclassification with the WHO criteria for neuroendocrine tumors, 23 patients had typical carcinoid tumors with thoracic lymph node involvement. At the last follow-up, 19 patients had no evidence of disease (NED), 2 patients had developed systemic metastases (SM) and are still alive, and 2 patients had died. Eleven patients had atypical carcinoid tumors with thoracic lymph node involvement. At the last follow-up, four patients had NED, seven patients had developed SM within a median time of 17 months, and six patients with SM died shortly thereafter (median survival time, 25.5 months), while one is still alive. Two patients had been reclassified with large cell neuroendocrine carcinoma at the time of this review; both of these patients had developed SM (at 4 months and 21 months after diagnosis) and had died (at 15 months and 21 months after diagnosis, respectively).

CONCLUSIONS

These data suggest that patients with atypical pulmonary carcinoid tumors with regional lymph node metastases have a high likelihood of developing recurrent disease if treated with surgical resection alone and have significantly worse outcome (p < 0.001) compared to those patients with typical carcinoid tumors with thoracic lymph node involvement.

Primary carcinoid tumor in a horseshoe kidney

A case of primary carcinoid tumor arising within a horseshoe kidney in a 51-year-old woman is reported. The tumor was found incidentally by computed tomography (CT) during a check-up for a suspected gall bladder polyp. Histologic, immunohistochemical and electron microscopic analyses of this tumor revealed features typical of carcinoid tumor. Primary carcinoid tumor of the kidney is extremely rare and only 32 cases were previously reported, including five cases in horseshoe kidneys. None of these five cases in horseshoe kidneys demonstrated any evidence of local or distant metastases and all were alive at the time of reporting without evidence of disease after up to 3 years of follow up. The present case, even with accompanying lymph nodal metastasis, also has had no evidence of local recurrence or distant metastasis for 3 years post operation. Primary carcinoid tumor arising within horseshoe kidneys appear to be more benign than those within non-horseshoe kidneys.

Recent advances in systemic therapy for gastrointestinal neuroendocrine tumors

Neuroendocrine tumors of the gastrointestinal tract are rare tumors which can be classified as amine precursor uptake and decarboxylation tumors (APU-Domas). Although the majority of clinically apparent tumors are malignant, they are frequently slow growing. Despite this characteristic, they may generate disabling hormonal syndromes requiring aggressive treatment to achieve palliation. Recent advances in understanding the pathophysiology of these tumors has led to better medical therapy with chemotherapeutic agents, somatostatin analogues, and biologic therapies. This review will update the recent efforts in systemic therapies of the gastrointestinal neuroendocrine tumors.

Middle ear carcinoid: an indolent tumor with metastatic potential

BACKGROUND

Neuroendocrine tumors of the head and neck region may present problems in diagnosis. Middle ear carcinoid is a rare, recently recognized tumor, which to date has not been reported to metastasize.

METHODS

We report the case of a 64-year-old man with a 9-year history of recurrent middle ear neoplasm and ipsilateral cervical lymphadenopathy. A microscopic parathyroid tumor was also identified. The approach to the diagnosis of this unusual combination is presented.

RESULTS

The patient had a neuroendocrine tumor metastatic to multiple unilateral cervical lymph nodes, which was morphologically identical to his recurrent middle ear neoplasm. The neoplasm had the morphologic, immunohistochemical, and ultrastructural features of a carcinoid tumor.

CONCLUSIONS

This case illustrates that middle ear carcinoids may metastasize. We suggest that immunohistochemical studies be performed on all biopsy specimens from neoplasms of the middle ear, as distinction from the more common paraganglioma may be difficult on morphologic grounds alone.

Antitumor effect of a neutralizing antibody to vascular endothelial growth factor on liver metastasis of endocrine neoplasm

Distant metastasis of gastrointestinal endocrine neoplasm is resistant to currently available treatments. Because hematogenic metastasis is dominant, anti-angiogenic drugs are expected to be a novel therapy for this neoplasm. In the present study, the therapeutic effect of vascular endothelial growth factor neutralizing antibody (VEGFAb) on liver metastasis of an endocrine neoplasm was investigated experimentally. Cecal transplantation into nude mice of small pieces of EN-1, a xenotransplanted human intestinal endocrine neoplasm, resulted in liver metastasis. A treated group (n = 19) received 100 micrograms/mouse of VEGFAb intraperitoneally on alternate days from day 10 after tumor transplantation, and the control group (n = 19) received saline. Five of the 19 control mice died of tumor progression, of which 2 could not be evaluated. The cecal tumor weighed 6316 +/- 2333 mg (n = 17) in the control group and 1209 +/- 837 mg (n = 19) in the treated group (P < 0.01) 6 weeks after transplantation. Liver metastasis developed in 16 of 17 control mice and in 2 of 19 treated mice (P < 0.01). The VEGF level of the whole cecal tumor in the control group was significantly higher than that in the treated group (305.1 +/- 174.1 vs. 54.7 +/- 41.2 mg; P < 0.001). VEGFAb did not cause any body weight loss (28.52 +/- 1.63 in the control vs. 28.44 +/- 1.71 g in the treated group). These results indicate that VEGFAb may be a novel therapeutic agent for endocrine neoplasm with distant metastasis.

Carcinoid disease: review of the literature

Carcinoid syndrome is the product of a rare but fascinating malignant neoplasm. Carcinoid syndrome was described more than 100 years ago, and recent advances in diagnostic localization, elucidation of the mechanisms of oncogenesis, treatment options, and, consequently, patient prognosis have been made. Current modalities of treatment, possible therapeutic implications of new avenues of research, and current literature on the chemotherapeutic combinations used are reviewed.

Clinicopathologic studies of thymic carcinoids in multiple endocrine neoplasia type 1

Thymic carcinoid is part of the multiple endocrine neoplasia type 1 (MEN1) syndrome occurring predominantly in male patients who were heavy smokers, presenting most commonly in middle age. In contrast with metastatic midgut carcinoids, MEN1-related thymic carcinoid is not associated with carcinoid syndrome, nor is it associated with Cushing syndrome, in contrast with sporadic thymic carcinoids. Local invasion and metastasis are common. Prognosis is poor because of late detection, lack of effective treatment, and the aggressive nature of the tumor. All patients with thymic carcinoids should be investigated for MEN1, including thorough clinical evaluation and family studies. Anterior mediastinal lesions in MEN1 male patients should be considered thymic carcinoids until proven otherwise. All male MEN1 patients and asymptomatic gene carriers should be warned of the risk of thymic carcinoids and the possible link to smoking. Computed tomography (CT) of the chest is recommended on first screening for MEN1 in male patients more than 25 years of age, followed by yearly chest X-rays and chest CT every 3 years. Prophylactic thymectomy should be carried out during subtotal or total parathyroidectomy on MEN1 patients.