Gastroenteropancreatic Neuroendocrine Tumors.

Neuroendocrine tumors (NETs) are heterogeneous malignancies arising from the diffuse neuroendocrine system. They frequently originate in the gastroenteropancreatic (GEP) tract and the bronchopulmonary tree, and their incidence has steadily increased in the last 3 decades. Fundamental biologic and genomic differences underlie the clinical heterogeneity of NETs, and distinct molecular features characterize NETs of different grades and different primary sites. Although surgery remains the cornerstone of treatment for localized tumors, systemic treatment options for patients with metastatic NETs have expanded considerably. Somatostatin analogs have demonstrated both antisecretory and antitumor efficacy. Peptide receptor radionuclide therapy with lutetium-177 dotatate (177 Lu-DOTATATE) has been approved for advanced GEP-NETs. The antitumor activity of everolimus has been demonstrated across a wide spectrum of NETs, and the antiangiogenic agent sunitinib has been approved for pancreatic NETs (pNETs). Chemotherapy with temozolomide and capecitabine has recently demonstrated an unprecedented prolongation of progression-free survival in a randomized trial of pNETs. Multiple retrospective series have reported the efficacy of liver-directed therapies both for palliating symptoms of hormone excess and for controlling tumor growth. Telotristat, an oral inhibitor of tryptophan hydroxylase, has been shown to reduce diarrhea in patients with carcinoid syndrome. Defining the therapeutic algorithm and identifying biomarkers predictive of response to treatments are among the main priorities for the next decade of research in the NET field.

EGFR is a potential therapeutic target for highly glycosylated and aggressive pancreatic neuroendocrine neoplasms.

pNENs are relative indolent tumors with heterogeneous clinical presentation at diagnosis. It is important to establish aggressive subgroups of pNENs and identify potential therapeutic targets. Patients with pNEN (322 cases) were included to examine the association between glycosylation biomarkers and clinical/pathological traits. The molecular and metabolic features stratified by glycosylation status were assessed by RNA-seq/whole exome sequencing and immunohistochemistry. A considerable proportion of patients had elevated glycosylation biomarkers (carbohydrate antigen [CA] 19-9, 11.9%; CA125, 7.5%; carcinoembryonic antigen [CEA], 12.8%). CA19-9 (hazard ratio [HR] = 2.26, P = .019), CA125 (HR = 3.79, P = .004) and CEA (HR = 3.16, P = .002) were each independent prognostic variables for overall survival. High glycosylation group, defined as pNENs with elevated level of circulating CA19-9, CA125 or CEA, accounted for 23.4% of all pNENs. High glycosylation (HR = 3.14, P = .001) was an independent prognostic variable for overall survival and correlated with G3 grade (P < .001), poor differentiation (P = .001), perineural invasion (P = .004) and distant metastasis (P < .001). Epidermal growth factor receptor (EGFR) was enriched in high glycosylation pNENs using RNA-seq. EGFR was expressed in 21.2% of pNENs using immunohistochemistry and associated with poor overall survival (P = .020). A clinical trial focusing on EGFR expressed pNENs was initiated (NCT05316480). Thus, pNEN with aberrant glycosylation correlates with a dismal outcome and suggests potential therapeutic target of EGFR.

177Lu-Dotatate plus long-acting octreotide versus high­dose long-acting octreotide in patients with midgut neuroendocrine tumours (NETTER-1): final overall survival and long-term safety results from an open-label, randomised, controlled, phase 3 trial.

BACKGROUND: The primary analysis of the phase 3 NETTER-1 trial showed significant improvement in progression-free survival with 177Lu-Dotatate plus long-acting octreotide versus high-dose long-acting octreotide alone in patients with advanced midgut neuroendocrine tumours. Here, we report the prespecified final analysis of overall survival and long-term safety results. METHODS: This open-label, randomised, phase 3 trial enrolled patients from 41 sites in eight countries across Europe and the USA. Patients were 18 years and older with locally advanced or metastatic, well differentiated, somatostatin receptor-positive midgut neuroendocrine tumours (Karnofsky performance status score ≥60) and disease progression on fixed-dose long-acting octreotide. Patients were randomly assigned (1:1) via an interactive web-based response system to intravenous 177Lu-Dotatate 7·4 GBq (200 mCi) every 8 weeks (four cycles) plus intramuscular long-acting octreotide 30 mg (177Lu-Dotatate group) or high-dose long-acting octreotide 60 mg every 4 weeks (control group). The primary endpoint of progression-free survival has been previously reported; here, we report the key secondary endpoint of overall survival in the intention-to-treat population. Final overall survival analysis was prespecified to occur either after 158 deaths or 5 years after the last patient was randomised, whichever occurred first. During long-term follow-up, adverse events of special interest were reported in the 177Lu-Dotatate group only. This trial is registered with ClinicalTrials.gov, NCT01578239. FINDINGS: From Sept 6, 2012, to Jan 14, 2016, 231 patients were enrolled and randomly assigned for treatment. The prespecified final analysis occurred 5 years after the last patient was randomly assigned (when 142 deaths had occurred); median follow-up was 76·3 months (range 0·4-95·0) in the 177Lu-Dotatate group and 76·5 months (0·1-92·3) in the control group. The secondary endpoint of overall survival was not met: median overall survival was 48·0 months (95% CI 37·4-55·2) in the 177Lu-Dotatate group and 36·3 months (25·9-51·7) in the control group (HR 0·84 [95% CI 0·60-1·17]; two-sided p=0·30). During long-term follow-up, treatment-related serious adverse events of grade 3 or worse were recorded in three (3%) of 111 patients in the 177Lu-Dotatate group, but no new treatment-related serious adverse events were reported after the safety analysis cutoff. Two (2%) of 111 patients given 177Lu-Dotatate developed myelodysplastic syndrome, one of whom died 33 months after randomisation (this person was the only the only reported 177Lu-Dotatate treatment-related death). No new cases of myelodysplastic syndrome or acute myeloid leukaemia were reported during long-term follow-up. INTERPRETATION: 177Lu-Dotatate treatment did not significantly improve median overall survival versus high-dose long-acting octreotide. Despite final overall survival not reaching statistical significance, the 11·7 month difference in median overall survival with 177Lu-Dotatate treatment versus high-dose long-acting octreotide alone might be considered clinically relevant. No new safety signals were reported during long-term follow-up. FUNDING: Advanced Accelerator Applications, a Novartis company.

Preclinical evaluation of [225Ac]Ac-DOTA-TATE for treatment of lung neuroendocrine neoplasms.

PURPOSE: There is significant interest in the development of targeted alpha-particle therapies (TATs) for treatment of solid tumors. The metal chelator-peptide conjugate, DOTA-TATE, loaded with the ß-particle emitting radionuclide 177Lu ([177Lu]Lu-DOTA-TATE) is now standard care for neuroendocrine tumors that express the somatostatin receptor 2 (SSTR2) target. A recent clinical study demonstrated efficacy of the corresponding [225Ac]Ac-DOTA-TATE in patients that were refractory to [177Lu]Lu-DOTA-TATE. Herein, we report the radiosynthesis, toxicity, biodistribution (BD), radiation dosimetry (RD), and efficacy of [225Ac]Ac-DOTA-TATE in small animal models of lung neuroendocrine neoplasms (NENs). METHODS: [225Ac]Ac-DOTA-TATE was synthesized and characterized for radiochemical yield, purity and stability. Non-tumor-bearing BALB/c mice were tested for toxicity and BD. Efficacy was determined by single intravenous injection of [225Ac]Ac-DOTA-TATE into SCID mice-bearing human SSTR2 positive H727 and H69 lung NENs. RD was calculated using the BD data. RESULTS: [225Ac]Ac-DOTA-TATE was synthesized with 98% yield, 99.8% purity, and displayed 97% stability after 2 days incubation in human serum at 37 °C. All animals in the toxicity study appeared healthy 5 months post injection with no indications of toxicity, except that animals that received ≥111 kBq of [225Ac]Ac-DOTA-TATE had chronic progressive nephropathy. BD studies revealed that the primary route of elimination is by the renal route. RD calculations determined pharmacokinetics parameters and absorbed α-emission dosages from 225Ac and its daughters. For both tumor models, a significant tumor growth delay and time to experimental endpoint were observed following a single administration of [225Ac]Ac-DOTA-TATE relative to controls. CONCLUSIONS: These results suggest significant potential for the clinical translation of [225Ac]Ac-DOTA-TATE for lung NENs.

Efficacy and Toxicity Analysis of Capecitabine and Temozolomide in Neuroendocrine Neoplasms.

BACKGROUND: The capecitabine/temozolomide (CAPTEM) regimen has significant activity in advanced neuroendocrine tumors (NETs). Questions exist regarding activity in pancreatic versus nonpancreatic NETs, risk of opportunistic infections, long-term myelotoxicity, and safety of prolonged treatment duration. Analysis of large patient cohorts is needed for the evaluation of rare toxicities and assessment of risk factors. METHODS: We conducted a retrospective study of all patients with advanced NETs seen at Moffitt Cancer Center between January 2008 and June 2019 who received treatment with CAPTEM. RESULTS: A total of 462 patients were eligible. The objective radiographic response rate was 46%, and the disease control rate was 81%. Median progression-free survival (PFS) was 18 months (95% CI, 14.0-21.9 months) and median overall survival was 51 months (95% CI, 42.8-59.2 months): 62 months in well-differentiated NETs versus 14 months in poorly differentiated neuroendocrine carcinomas (P<.0001). Patients with primary pancreatic tumors had the highest partial response rates and longest median PFS. Incidences of grade 4 thrombocytopenia and neutropenia were 7% and 3%, respectively, and substantially higher in women than men (P=.02 and P=.004, respectively). Only 1 case (0.2%) of suspected Pneumocystis pneumonia (PCP) was observed in a patient receiving corticosteroids. Three patients developed myelodysplastic disease, all of whom had received prior peptide receptor radiotherapy (PRRT). There were no acute treatment-related deaths; 1 patient died 2 months after a thrombocytopenic bleed. CONCLUSIONS: The CAPTEM regimen is exceptionally safe. Efficacy is particularly robust in well-differentiated pancreatic NETs. Severe myelotoxicity is rare; the risk of grade 4 cytopenias is significantly increased in women, and therefore sex-based dosing should be considered. There were no cases of myelodysplastic syndromes, except among patients who had received PRRT, a known risk factor. The risk of PCP is negligible.

Neuroendocrine and Adrenal Tumors, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology.

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Neuroendocrine and Adrenal Gland Tumors focus on the diagnosis, treatment, and management of patients with neuroendocrine tumors (NETs), adrenal tumors, pheochromocytomas, paragangliomas, and multiple endocrine neoplasia. NETs are generally subclassified by site of origin, stage, and histologic characteristics. Appropriate diagnosis and treatment of NETs often involves collaboration between specialists in multiple disciplines, using specific biochemical, radiologic, and surgical methods. Specialists include pathologists, endocrinologists, radiologists (including nuclear medicine specialists), and medical, radiation, and surgical oncologists. These guidelines discuss the diagnosis and management of both sporadic and hereditary neuroendocrine and adrenal tumors and are intended to assist with clinical decision-making. This article is focused on the 2021 NCCN Guidelines principles of genetic risk assessment and counseling and recommendations for well-differentiated grade 3 NETs, poorly differentiated neuroendocrine carcinomas, adrenal tumors, pheochromocytomas, and paragangliomas.

Pembrolizumab monotherapy in patients with previously treated metastatic high-grade neuroendocrine neoplasms: joint analysis of two prospective, non-randomised trials.

BACKGROUND: Metastatic high-grade neuroendocrine neoplasms (G3NENs) have limited treatment options after progression on platinum-based therapy. We addressed the role of Pembrolizumab in patients with previously treated metastatic G3NENs. METHODS: Two open-label, phase 2 studies enrolled patients with G3NEN (Ki-67 > 20%) to receive Pembrolizumab at 200 mg I.V. every 3 weeks. Radiographic evaluation was conducted every 9 weeks with overall response rate as the primary endpoint. RESULTS: Between November 2016 and May 2018, 29 patients (13 males/16 females) with G3NENs were enrolled. One patient (3.4%) had an objective response and an additional six patients (20.7%) had stable disease, resulting in a disease control rate of 24.1%. Disease control rate (DCR) at 18 weeks was 10.3% (3/29). There was no difference in the DCR, PFS or OS between the PD-L1-negative and -positive groups (p 0.56, 0.88 and 0.55, respectively). Pembrolizumab was well tolerated with only 9 grade 3, and no grade 4 events considered drug-related. CONCLUSIONS: Pembrolizumab can be safely administered to patients with G3NENs but has limited activity as a single agent. Successful completion of our trials suggest studies in G3NENs are feasible and present an unmet need. Further research to identify active combination therapies should be considered. CLINICAL TRIAL REGISTRATION NUMBER: NCT02939651 (10/20/2016).

A Phase II Study of Ibrutinib in Advanced Neuroendocrine Neoplasms.

BACKGROUND: Ibrutinib is an orally administered inhibitor of Bruton's tyrosine kinase (Btk). Preclinical data suggest that mast cells are recruited within neuroendocrine neoplasms (NENs) where they stimulate angiogenesis and tumor growth. Ibrutinib inhibits mast cell degranulation and has been associated with regression of tumors in a mouse insulinoma model. METHODS: A prospective, phase II trial evaluated patients with advanced gastrointestinal (GI)/lung NENs and pancreatic NENs (pNENs) who had evidence of progression within 12 months of study entry on at least one prior therapy. Patients received ibrutinib 560 mg daily until unacceptable toxicity, progression of disease, or withdrawal of consent. The primary endpoint was objective response rate. RESULTS: Twenty patients were enrolled on protocol from November 2015 to December 2017 (15 advanced GI/lung NENs and 5 pNENs). No patient reached an objective response. Median PFS was 3.0 months. A total of 44 drug-related adverse events (AEs) were captured as probably or definitely associated with ibrutinib. Five patients experienced probably or definitely related grade 3 AEs, and 1 patient experienced a probably related grade 4 AE. Five patients discontinued treatment prior to radiographic assessment. CONCLUSIONS: Ibrutinib does not show significant evidence of activity in well-differentiated gastroenteropancreatic and lung NENs.

The Role of Perioperative Systemic Therapy in Localized Pancreatic Neuroendocrine Neoplasms.

BACKGROUND: The role of perioperative systemic therapy (PST) in the management of localized pancreatic neuroendocrine neoplasms (PanNEN) is unclear. OBJECTIVES: We aimed to evaluate the benefit of PST compared to surgery alone (SA) in patients with localized PanNEN. METHOD: We selected patients with stages I-III PanNEN who underwent curative-intent surgical resection in National Cancer Database from 2006 to 2014. Patients who had both PST and surgical resection were matched with patients who received SA by propensity score at 1-to-1 ratio with nearest neighbor method. RESULTS: Four thousand eight hundred and ninety-two patients were included in this study with median age of 60 years. Factors associated with significant more use of PST compared to SA included age <65 years, community medical facilities, grade 3 tumor, tumor in the pancreatic head, T34 tumor, and N1 tumor. Three hundred and one PST patients were matched with 301 SA patients. In the matched cohort, the PST group had significantly shorter overall survival (OS) compared to the SA group (median overall both not reached, p = 0.037). This finding was confirmed by multivariable Cox proportional hazards regression in the original cohort (hazard ratio [HR] 1.45, 95% CI 1.11-1.89, p = 0.006). Subgroup analyses showed that adjuvant therapy was not associated with improved OS in grades 1-2 PanNEN (HR 2.03, 95% CI 1.31-3.16, p = 0.002). CONCLUSIONS: PST stratified by grade and neoadjuvant or adjuvant therapy compared to SA was not associated with improved OS in patients with localized PanNEN. PST for localized PanNEN should be used with caution until prospective data are available.

The Evolving Treatment Algorithm for Advanced Neuroendocrine Neoplasms: Diversity and Commonalities Across Tumor Types.

Neuroendocrine neoplasms (NEN) most commonly arise in the gastroenteropancreatic system and lungs. The incidence of NEN is increasing globally, with improved diagnostic techniques identifying patients with early-stage disease. The number of approved therapies for the treatment of advanced disease has grown substantially in the past decade. The treatment algorithm for advanced NEN is evolving from one that is directed by primary site-specific classification to one that is directed by biologic classification, as evidenced by overlapping systemic treatments across the primary tumor sites. Commonalities in biologic characteristics across primary sites include functional status, differentiation status, grade, level of somatostatin receptor expression, and genetic alterations. In this review, we discuss current clinical evidence and available therapies for the treatment of advanced NEN and highlight the need for prospective trials in patients with well-differentiated, high-grade NEN. IMPLICATIONS FOR PRACTICE: This review raises awareness of the evolution of the treatment algorithm for advanced neuroendocrine neoplasms (NEN) from one that is directed by primary tumor site-specific classification to one that is directed by biologic classification. In addition, this review promotes understanding of the new pathologic category of well-differentiated G3 pancreatic neuroendocrine tumors and highlights the need for prospective trials in this patient population, for whom there is currently no standard of care. This review further provides a conceptual treatment schematic that categorizes the recommendations for systemic treatments for advanced disease by biologic classification, including the new and established categories of NEN.

Follow-Up for Resected Gastroenteropancreatic Neuroendocrine Tumours: A Practice Survey of the Commonwealth Neuroendocrine Tumour Collaboration (CommNETS) and the North American Neuroendocrine Tumor Society (NANETS).

OBJECTIVES: There is no consensus regarding optimal follow-up in resected gastroenteropancreatic neuroendocrine tumours (NETs). We aimed to perform a practice survey to ascertain follow-up patterns by health care practitioners and highlight areas of variation that may benefit from further quantitative research. METHODS: A Web-based survey targeted at NET health care providers in Australia, New Zealand, Canada, and the USA was developed by a steering committee of medical oncologists and a research methodologist. Thirty-seven questions elicited information regarding adherence to guidelines, the influence of risk factors on follow-up, and the frequency and choice of modality in follow-up. RESULTS: There were 163 respondents: 59 from Australia, 25 from New Zealand, 46 from Canada, and 33 from the USA (50% medical oncology, 23% surgery, 13% nuclear medicine, and 15% other). Thirty-eight percent of the respondents were "very familiar" with the NCCN NET guidelines, 33% with the ENETS guidelines, and 17% with the ESMO guidelines; however, only 15, 27, and 10%, respectively, found them "very useful"; 63% reported not using guidelines at their institution. The commonest investigations used were CT scans (66%) and chromogranin A (86%). The US respondents were more likely to follow patients up past 5 years, and the Australian respondents utilized more functional and less cross-sectional imaging. When poor prognostic factors were introduced, the respondents recommended more visits and tests. CONCLUSIONS: This large international survey highlights variation in current follow-up practices not well addressed by the current guidelines. More quantitative research is required to inform the development of evidence-based guidelines tailored to the pattern of recurrence in NETs.

NCCN Guidelines Insights: Neuroendocrine and Adrenal Tumors, Version 2.2018.

The NCCN Guidelines for Neuroendocrine and Adrenal Tumors provide recommendations for the management of adult patients with neuroendocrine tumors (NETs), adrenal gland tumors, pheochromocytomas, and paragangliomas. Management of NETs relies heavily on the site of the primary NET. These NCCN Guidelines Insights summarize the management options and the 2018 updates to the guidelines for locoregional advanced disease, and/or distant metastasis originating from gastrointestinal tract, bronchopulmonary, and thymus primary NETs.

Health-related quality of life for everolimus versus placebo in patients with advanced, non-functional, well-differentiated gastrointestinal or lung neuroendocrine tumours (RADIANT-4): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: In the phase 3 RADIANT-4 trial, everolimus increased progression-free survival compared with placebo in patients with advanced, progressive, non-functional, well-differentiated gastrointestinal or lung neuroendocrine tumours (NETs). We now report the health-related quality of life (HRQOL) secondary endpoint. METHODS: RADIANT-4 is a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial done in 97 centres in 25 countries worldwide. Adults (aged ≥18 years) were eligible for the study if they had pathologically confirmed, advanced (unresectable or metastatic), non-functional, well-differentiated (grade 1 or 2) NETs of lung or gastrointestinal origin. Patients were randomly allocated (2:1) using block randomisation (block size of three) by an interactive voice response system to receive oral everolimus (10 mg per day) or placebo, both with best supportive care, with stratification by tumour origin, WHO performance status, and previous somatostatin analogue treatment. HRQOL was assessed with the Functional Assessment of Cancer Therapy-General (FACT-G) questionnaire at baseline (visit 2, day 1), every 8 weeks (±â€ˆ1 week) during the study for the first 12 months after randomisation, and every 12 weeks thereafter until study drug discontinuation. The primary endpoint, reported previously, was progression-free survival assessed by central review; HRQOL was a prespecified secondary endpoint. The prespecified secondary outcome measure was time to definitive deterioration (≥7 points) in FACT-G total score. Analyses were done on the full analysis set, consisting of all randomised patients, by intention to treat. Only data obtained while receiving the randomly allocated treatment were included in this analysis. Enrolment for RADIANT-4 was completed on Aug 23, 2013, but the trial is ongoing pending final analysis of the key secondary endpoint of overall survival. This trial is registered with ClinicalTrials.gov, number NCT01524783. FINDINGS: Between April 3, 2012, and Aug 23, 2013, 302 patients were enrolled; 205 were randomly allocated everolimus and 97 were assigned placebo. At baseline, 193 (94%) of 205 patients assigned everolimus and 95 (98%) of 97 allocated placebo had completed either fully or partly the FACT-G questionnaire; at week 48, 70 (83%) of 84 patients assigned everolimus and 22 (85%) of 26 allocated placebo completed FACT-G. Median time to definitive deterioration in FACT-G total score was 11·27 months (95% CI 9·27-19·35) with everolimus and 9·23 months (5·52-not estimable) with placebo (adjusted hazard ratio 0·81, 95% CI 0·55-1·21; log-rank p=0·31). INTERPRETATION: HRQOL was maintained for patients with advanced, non-functional, gastrointestinal or lung NETs, with no relevant differences noted between the everolimus and placebo groups. In view of the previous RADIANT-4 findings of longer progression-free survival with everolimus, our findings suggest that everolimus delays disease progression while preserving overall HRQOL, even with the usual toxic effects related to active targeted drug treatment for cancer. FUNDING: Novartis Pharmaceuticals.

A phase II trial of bevacizumab plus temsirolimus in patients with advanced hepatocellular carcinoma.

BACKGROUND: There is strong rationale to combine temsirolimus (TEM) with Bevacizumab (BEV) for patients with advanced HCC. METHODS: A modified two-stage Simon phase II trial was performed with plans to advance to stage 2 if more than 2 patients had confirmed PR or >18 patients were progression free at 6 months out of 25 in stage 1. Toxicity, PFS and overall survival were secondary endpoints. Eligible pts had advanced HCC, Child Pugh A liver status and no prior systemic therapy involving the VEGF or m-TOR targeted agents. Patients were treated with temsirolimus 25 mg IV on Days 1, 8, 15, and 22 of a 28 day cycle and bevacizumab 10 mg/kg IV on Days 1 and 15 of the cycle. RESULTS: Twenty-eight eligible patients were enrolled, 26 evaluable receiving a median of 6.5 cycles (range 1-18). Drug related toxicities were common including cytopenias, fatigue, mucositis, diarrhea and mild bleeds. Dose reductions or discontinuation of TEM were common. Accrual closed for presumed futility after interim analysis of the first 25 evaluable patients showed only one PR and 16/25 were progression-free at 6 months. However, the final data update in March 2013 demonstrated 4 confirmed PRs, a 5th unconfirmed PR and 16 /26 progression-free at 6 months. Median PFS and OS were 7 and 14 months respectively. CONCLUSION: This first-line HCC trial evaluating the BEV/TEM doublet reports an ORR of 19 % and OS of 14 months which is favorable but requires further study at a more optimized dose and schedule.

Temozolomide in Advanced Neuroendocrine Neoplasms: Pharmacological and Clinical Aspects.

Alkylating agents, such as streptozocin and dacarbazine, have been reported as active in neuroendocrine neoplasms (NENs). Temozolomide (TMZ) is an oral, potentially less toxic derivative of dacarbazine, which has shown activity both as a single agent and in combination with other drugs. Nevertheless, its role in NENs has not been well defined. Several retrospective and prospective phase I-II studies have been published describing its use in a variety of NENs. In a retrospective series, the combination of capecitabine and TMZ was reported to be associated with a particularly high tumour response in pancreatic NENs as a first-line treatment. Although in NENs, determination of the O6-methylguanine-DNA methyltransferase (MGMT) status has been suggested as a predictive biomarker of response, its role still remains investigational, awaiting validation along with the establishment of the optimal detection method. Metronomic schedules have been reported to potentially overcome MGMT-related drug resistance. Toxicity is manageable if well monitored. We reviewed the literature regarding pharmacological and clinical aspects of TMZ, focusing on specific settings of NENs, different schedules, toxicity and safety profiles, and potential predictive biomarkers of response.

Neuroendocrine tumors, version 1.2015.

Neuroendocrine tumors (NETs) comprise a broad family of tumors that may or may not be associated with symptoms attributable to hormonal hypersecretion. The NCCN Clinical Practice Guidelines in Oncology for Neuroendocrine Tumors discuss the diagnosis and management of both sporadic and hereditary NETs. This selection from the guidelines focuses on sporadic NETs of the pancreas, gastrointestinal tract, lung, and thymus.

Familial gastrointestinal stromal tumor syndrome: report of 2 cases with KIT exon 11 mutation.

BACKGROUND: As with cases of sporadic gastrointestinal stromal tumor (GIST), familial GIST syndrome arises from mutations in KIT or PDGFRA. Only a few dozen such families have been described in the literature. METHODS: Cases of 2 individuals from 2 different newly described kindreds with familial GIST syndrome were retrospectively reviewed. Pertinent immunohistochemical stains, including CD117, CD34, DOG1, desmin, and S100, were performed. Samples from each case were sent to outside facilities for molecular analysis. A review of the relevant literature was performed and the number of familial GIST syndrome cases reported was updated through July 2014. RESULTS: In case 1, a woman 40 years of age with a family history of GIST presented with abdominal pain and gastrointestinal bleeding. Biopsy of a gastric mass revealed spindle-cell type GIST. Molecular analysis revealed a heterozygous mutation of p.Asp579del in exon 11 of KIT. The patient was placed on imatinib therapy and an initial positive response was demonstrated by imaging. Disease regression was seen on computed tomography, and several GIST tumors were surgically resected. The patient has had stable disease since surgery. In case 2, an asymptomatic woman 29 years of age presented for screening due to a family history of GIST. One small nodule was noted in her stomach and another was noted in the duodenum; both were surgically resected. The patient recovered well following surgery. The GIST in this patient was noted to have similar histological, immunohistochemical, and molecular findings as case 1. CONCLUSIONS: Imatinib has often been shown to be an effective therapy in both the familial and sporadic forms of GIST. There is no standard protocol for addressing the surveillance of patients with spindle-cell type GIST seen in the setting of familial GIST syndrome and with a p.Asp579del mutation of exon 11 on KIT.

Clinical benefits of above-standard dose of octreotide LAR in patients with neuroendocrine tumors for control of carcinoid syndrome symptoms: a multicenter retrospective chart review study.

BACKGROUND: Octreotide LAR is used in patients for control of carcinoid syndrome (CS) and other symptoms of hormone hypersecretion. The aim of this study was to examine reasons for octreotide LAR dose escalation and observe CS symptom improvement in patients with neuroendocrine tumors (NETs) who underwent octreotide LAR dose escalation at three cancer referral centers. METHODS: Medical records for patients with diagnosis of carcinoid or pancreatic NET who had received one dose or more of octreotide LAR above 30 mg every 4 weeks from 2000 to 2012 were reviewed. Reasons for dose escalation and symptomatic outcomes were abstracted for each patient 3 months prior to and up to 12 months following the dose escalation. RESULTS: Of the evaluated 239 NET patients, 53% were male, mean age at first dose escalation was 60 years (standard deviation [SD]: 11 years), and mean time from octreotide LAR initiation to first dose escalation was 1.7 years (SD: 2.0 years). The primary reasons reported for dose escalation were carcinoid or hormonal syndrome (62%) or radiographic progression (28%). The most common dose changes at the first dose escalation were 40 mg every 4 weeks (71%) and 60 mg every 4 weeks (18%). Of 90 patients in whom flushing was reported prior to first dose escalation, 73 (81%) were reported to have experienced improvement or resolution of their symptoms following the dose escalation. Of 107 patients who were reported to have experienced diarrhea before the first dose escalation, 85 (79%) were reported to have experienced improvement or resolution after first dose escalation. CONCLUSION: The goal of improved symptom control is a common reason for dose escalation of octreotide LAR. This study suggests that escalation to above the standard dose of octreotide LAR of 30 mg every 4 weeks may result in improved CS symptom control.

Systemic treatment of gastroenteropancreatic neuroendocrine tumors (GEP-NETS): current approaches and future options.

OBJECTIVE: To describe recent advances in the treatment of gastroenteropancreatic neuroendocrine tumors (GEP-NETs). METHODS: A review of the published English language literature on GEP-NET therapy with a focus on practice-changing clinical trials. RESULTS: Somatostatin analog (SSA) treatment remains a cornerstone of GEP-NET therapy, primarily for patients with hormonally functional tumors and midgut carcinoids. The biologic agents everolimus and sunitinib have similar tumor-stabilizing effects in pancreatic NETs and are both approved to treat progressive low-intermediate-grade tumors. Their role in nonpancreatic NETs remains controversial. Cytotoxic chemotherapy is effective against pancreatic NETs, but modern prospective data is lacking. Radiolabeled SSAs will likely become more widely available once phase III randomized studies are completed. CONCLUSIONS: New treatment options for GEP-NETs have become available and highlight the necessity of developing predictive biomarkers that will allow for appropriate and individualized therapy selection.