Initiation of Somatostatin analogues for neuroendocrine tumor patients: a cost-effectiveness analysis

BACKGROUND & AIMS

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are heterogeneous neoplasms. Although some have a relatively benign and indolent natural history, others can be aggressive and ultimately fatal. Somatostatin analogues (SSAs) improve both quality of life and survival for these patients once they develop metastatic disease. However, these drugs are costly and their cost-effectiveness is not known.

METHODS

A decision-analytic model was developed and analyzed to compare two treatment strategies for patients with Stage IV GEP-NETs. The first strategy had all patients start SSA immediately while the second strategy waited, reserving SSA initiation until the patient showed signs of progression. Sensitivity analysis was performed to explore model parameter uncertainty.

RESULTS

Our model of patients age 60 with metastatic GEP-NETs suggests empiric initiation of SSA led to an increase 0.62 unadjusted life-years and incremental increase in quality-adjusted life years (QALYs) of 0.44. The incremental costs were $388,966 per QALY and not cost-effective at a willingness-to-pay threshold of $100,000. Death was attributed to GEP-NETs for 94.1% of patients in the SSA arm vs. 94.9% of patients in the DELAY SSA arm. Sensitivity analysis found that the model was most sensitive to costs of SSAs. Using probabilistic sensitivity analysis, the SSA strategy was only cost-effective 1.4% of the time at a WTP threshold of $100,000 per QALY.

CONCLUSIONS

Our modeling study finds it is not cost-effective to initiate SSAs at time of presentation for patients with metastatic GEP-NETs. Further clinical studies are needed to identify the optimal timing to initiate these drugs.

Racial Differences in Gastroenteropancreatic Neuroendocrine Tumor Treatment and Survival in the United States

OBJECTIVES

The objective of this study was to evaluate racial differences in cancer treatment and survival in gastroenteropancreatic neuroendocrine tumor (GEP-NET) patients.

METHODS

Using the Surveillance, Epidemiology, and End Results Registry, we identified patients with GEP-NETs of the stomach, small intestine (SI), colon, rectum, appendix, and pancreas diagnosed between 1973 and 2014. Demographic, cancer, and treatment information were collected and compared using χ2 tests. Multivariable logistic and Cox regression were used to determine disparities in receiving treatment and overall survival.

RESULTS

We identified 19,031 GEP-NET patients: 2839 were non-Hispanic Blacks, 12,832 non-Hispanic Whites, 2098 Hispanics, and 1262 Asians. African Americans and Hispanics with SI and pancreatic NETs were less likely to be treated with surgery (odds ratio, 0.6; 95% confidence interval [CI], 0.46-0.69; odds ratio, 0.71; 95% CI, 0.51-0.99, respectively). African American race was not an independent predictor of survival; there was a strong trend in stomach, SI, and pancreas NETs (hazard ratio [HR], 1.31; 95% CI, 1-1.7; HR, 1.2; 95% CI, 0.99-1.45; HR, 1.22; 95% CI, 1-1.48, respectively).

CONCLUSIONS

Our study provides evidence of racial disparities in treatment and survival across GEP-NET primary sites and racial groups. Further studies should be performed to improve our understanding of the reason for these disparities.

French patient-reported experience of diagnosis, management and burden of neuroendocrine tumors

Background: There is a lack of knowledge regarding the experience of patients with neuroendocrine tumors (NET) in France. Materials & methods: A patient survey that captured information on diagnosis, disease impact/management and awareness was conducted. Data of respondents from France were analyzed and compared with US data as a reference. Results: Key topics included delays in diagnosis, negative impact on quality of life, patient access to NET medical experts and treatments, and information on NET and treatments. Significant differences were observed between France and the USA regarding NET diagnosis. Conclusion: This survey highlights the considerable burden experienced by patients in France with NET and differences in patient experience between France and the USA that may result from different healthcare and social systems.

Prognostic Factors Associated With Progression for Advanced-Stage/G1 and G2 Small-Bowel Neuroendocrine Tumors After Multimodal Therapy: Experience From a Tertiary Referral Center

OBJECTIVES

Neuroendocrine tumors represent approximately 40% of primary small bowel malignancies. However, factors predictive of progression after multimodal surgical therapy have not been well described. We evaluated the characteristics of small bowel neuroendocrine tumor patients associated with progression after multimodal surgical resection.

METHODS

A retrospective chart review identified 99 stage III and stage IV small bowel neuroendocrine tumor patients at Mount Sinai diagnosed and treated with surgery between 2005 and 2019. Progression-free survival (PFS) was defined as time from surgery until progression in surveillance radiologic imaging. Kaplan-Meier method was used to calculate PFS. Cox proportional hazard models were used to study the prognostic factors for PFS.

RESULTS

Of 99 patients, 48 had tumor progression during the follow-up period. Median PFS was 5.7 years (95% confidence interval [CI], 3.73-8.66) for the entire cohort. Prognostic factors for PFS were age at diagnosis (hazard ratio [HR], 1.04; 95% CI, 1.01-1.07), perineural invasion (HR, 2.19; 95% CI, 1.13-4.23), and elevated preoperative chromogranin level (HR, 2.31; 95% CI, 1.01-5.27).

CONCLUSIONS

Age at diagnosis, perineural invasion, and elevated preoperative chromogranin level may play a prognostic role in PFS.

Impact of liver tumour burden, alkaline phosphatase elevation, and target lesion size on treatment outcomes with 177Lu-Dotatate: an analysis of the NETTER-1 study

PURPOSE

To assess the impact of baseline liver tumour burden, alkaline phosphatase (ALP) elevation, and target lesion size on treatment outcomes with ¹⁷⁷Lu-Dotatate.

METHODS

In the phase 3 NETTER-1 trial, patients with advanced, progressive midgut neuroendocrine tumours (NET) were randomised to 177Lu-Dotatate (every 8 weeks, four cycles) plus octreotide long-acting release (LAR) or to octreotide LAR 60 mg. Primary endpoint was progression-free survival (PFS). Analyses of PFS by baseline factors, including liver tumour burden, ALP elevation, and target lesion size, were performed using Kaplan-Meier estimates; hazard ratios (HRs) with corresponding 95% CIs were estimated using Cox regression.

RESULTS

Significantly prolonged median PFS occurred with ¹⁷⁷Lu-Dotatate versus octreotide LAR 60 mg in patients with low (< 25%), moderate (25-50%), and high (> 50%) liver tumour burden (HR 0.187, 0.216, 0.145), and normal or elevated ALP (HR 0.153, 0.177), and in the presence or absence of a large target lesion (diameter > 30 mm; HR, 0.213, 0.063). Within the ¹⁷⁷Lu-Dotatate arm, no significant difference in PFS was observed amongst patients with low/moderate/high liver tumour burden (P = 0.7225) or with normal/elevated baseline ALP (P = 0.3532), but absence of a large target lesion was associated with improved PFS (P = 0.0222). Grade 3 and 4 liver function abnormalities were rare and did not appear to be associated with high baseline liver tumour burden.

CONCLUSIONS

¹⁷⁷Lu-Dotatate demonstrated significant prolongation in PFS versus high-dose octreotide LAR in patients with advanced, progressive midgut NET, regardless of baseline liver tumour burden, elevated ALP, or the presence of a large target lesion. Clinicaltrials.gov : NCT01578239, EudraCT: 2011-005049-11.

A phase 2 study of an oral mTORC1/mTORC2 kinase inhibitor (CC-223) for non-pancreatic neuroendocrine tumors with or without carcinoid symptoms

Second-generation mammalian target of rapamycin (mTOR) inhibitors such as CC-223 may have theoretical advantages over first-generation drugs by inhibiting TOR kinase in mTOR complex 1 (mTORC1) and 2 (mTORC2), potentially improving clinical efficacy for well-differentiated neuroendocrine tumors (NET).Enrolled patients had metastatic, well-differentiated NET of non-pancreatic gastrointestinal or unknown origin, with/without carcinoid symptoms, had failed ≥1 systemic chemotherapy, and were taking a somatostatin analog (SSA). Oral once-daily CC-223 was administered in 28-day cycles starting at 45 mg (n = 24), with a subsequent cohort starting at 30 mg (n = 23). Objectives were to evaluate tolerability, preliminary efficacy, and pharmacokinetic and biomarker profiles of CC-223. Forty-seven patients completed the study, with mean treatment duration of 378 days and mean dose of 26 mg; 26% of patients remained on the starting dose. Most frequent grade ≥3 toxicities were diarrhea (38%), fatigue (21%), and stomatitis (11%). By investigator, 3 of 41 evaluable patients (7%) showed partial response (PR) and 34 (83%) had stable disease (SD) for a disease control rate (DCR) of 90% (95% confidence interval [CI] 76.9–97.3%). Duration of PR was 125–401 days; median SD duration was 297 days (min–max, 50–1519 days). Median progression-free survival was 19.5 months (95% CI 10.4–28.5 months). Carcinoid symptoms of flushing, diarrhea, or both improved in 50%, 41%, and 39% of affected patients, respectively. For the first time, this study describes that a second-generation mTOR pathway inhibitor can result in highly durable tumor regression and control of NET carcinoid symptoms. The manageable safety profile, high DCR, and durable response, coupled with reduction in carcinoid symptoms refractory to SSA, make CC-223 a promising agent for further development.

Health-Related Quality of Life in Patients With Progressive Midgut Neuroendocrine Tumors Treated With 177Lu-Dotatate in the Phase III NETTER-1 Trial

Purpose Neuroendocrine tumor (NET) progression is associated with deterioration in quality of life (QoL). We assessed the impact of ¹⁷⁷Lu-Dotatate treatment on time to deterioration in health-related QoL. Methods The NETTER-1 trial is an international phase III study in patients with midgut NETs. Patients were randomly assigned to treatment with ¹⁷⁷Lu-Dotatate versus high-dose octreotide. European Organisation for Research and Treatment of Cancer quality-of-life questionnaires QLQ C-30 and G.I.NET-21 were assessed during the trial to determine the impact of treatment on health-related QoL. Patients completed the questionnaires at baseline and every 12 weeks until tumor progression. QoL scores were converted to a 100-point scale according to European Organisation for Research and Treatment of Cancer instructions, and individual changes from baseline scores were assessed. Time to QoL deterioration (TTD) was defined as the time from random assignment to the first QoL deterioration ≥ 10 points for each patient in the corresponding domain scale. All analyses were conducted on the intention-to-treat population. Patients with no deterioration were censored at the last QoL assessment date. Results TTD was significantly longer in the ¹⁷⁷Lu-Dotatate arm (n = 117) versus the control arm (n = 114) for the following domains: global health status (hazard ratio [HR], 0.406), physical functioning (HR, 0.518), role functioning (HR, 0.580), fatigue (HR, 0.621), pain (HR, 0.566), diarrhea (HR, 0.473), disease-related worries (HR, 0.572), and body image (HR, 0.425). Differences in median TTD were clinically significant in several domains: 28.8 months versus 6.1 months for global health status, and 25.2 months versus 11.5 months for physical functioning. Conclusion This analysis from the NETTER-1 phase III study demonstrates that, in addition to improving progression-free survival, ¹⁷⁷Lu-Dotatate provides a significant QoL benefit for patients with progressive midgut NETs compared with high-dose octreotide.

Everolimus in Neuroendocrine Tumors of the Gastrointestinal Tract and Unknown Primary

PURPOSE

The RADIANT-4 randomized phase 3 study demonstrated significant prolongation of median progression-free survival (PFS) with everolimus compared to placebo (11.0 [95% CI 9.2-13.3] vs. 3.9 [95% CI 3.6-7.4] months) in patients with advanced, progressive, nonfunctional gastrointestinal (GI) and lung neuroendocrine tumors (NET). This analysis specifically evaluated NET patients with GI and unknown primary origin.

METHODS

Patients in the RADIANT-4 trial were randomized 2:1 to everolimus 10 mg/day or placebo. The effect of everolimus on PFS was evaluated in patients with NET of the GI tract or unknown primary site.

RESULTS

Of the 302 patients enrolled, 175 had GI NET (everolimus, 118; placebo, 57) and 36 had unknown primary (everolimus, 23; placebo, 13). In the GI subset, the median PFS by central review was 13.1 months (95% CI 9.2-17.3) in the everolimus arm versus 5.4 months (95% CI 3.6-9.3) in the placebo arm; the hazard ratio (HR) was 0.56 (95% CI 0.37-0.84). In the unknown primary patients, the median PFS was 13.6 months (95% CI 4.1-not evaluable) for everolimus versus 7.5 months (95% CI 1.9-18.5) for placebo; the HR was 0.60 (95% CI 0.24-1.51). Everolimus efficacy was also demonstrated in both midgut and non-midgut populations; a 40-46% reduction in the risk of progression or death was reported for patients in the combined GI and unknown primary subgroup. Everolimus had a benefit regardless of prior somatostatin analog therapy.

CONCLUSIONS

Everolimus showed a clinically meaningful PFS benefit in patients with advanced progressive nonfunctional NET of GI and unknown primary, consistent with the overall RADIANT-4 results, providing an effective new standard treatment option in this patient population and filling an unmet treatment need for these patients.

Everolimus in advanced, progressive, well-differentiated, non-functional neuroendocrine tumors: RADIANT-4 lung subgroup analysis

In the phase III RADIANT-4 study, everolimus improved median progression-free survival (PFS) by 7.1 months in patients with advanced, progressive, well-differentiated (grade 1 or grade 2), non-functional lung or gastrointestinal neuroendocrine tumors (NETs) vs placebo (hazard ratio, 0.48; 95% confidence interval [CI], 0.35-0.67; P < .00001). This exploratory analysis reports the outcomes of the subgroup of patients with lung NETs. In RADIANT-4, patients were randomized (2:1) to everolimus 10 mg/d or placebo, both with best supportive care. This is a post hoc analysis of the lung subgroup with PFS, by central radiology review, as the primary endpoint; secondary endpoints included objective response rate and safety measures. Ninety of the 302 patients enrolled in the study had primary lung NET (everolimus, n = 63; placebo, n = 27). Median PFS (95% CI) by central review was 9.2 (6.8-10.9) months in the everolimus arm vs 3.6 (1.9-5.1) months in the placebo arm (hazard ratio, 0.50; 95% CI, 0.28-0.88). More patients who received everolimus (58%) experienced tumor shrinkage compared with placebo (13%). Most frequently reported (≥5% incidence) grade 3-4 drug-related adverse events (everolimus vs. placebo) included stomatitis (11% vs. 0%), hyperglycemia (10% vs. 0%), and any infections (8% vs. 0%). In patients with advanced, progressive, well-differentiated, non-functional lung NET, treatment with everolimus was associated with a median PFS improvement of 5.6 months, with a safety profile similar to that of the overall RADIANT-4 cohort. These results support the use of everolimus in patients with advanced, non-functional lung NET. The trial is registered with ClinicalTrials.gov (no. NCT01524783).

Phase 3 Trial of 177Lu-Dotatate for Midgut Neuroendocrine Tumors

BACKGROUND

Patients with advanced midgut neuroendocrine tumors who have had disease progression during first-line somatostatin analogue therapy have limited therapeutic options. This randomized, controlled trial evaluated the efficacy and safety of lutetium-177 (¹⁷⁷Lu)-Dotatate in patients with advanced, progressive, somatostatin-receptor-positive midgut neuroendocrine tumors.

METHODS

We randomly assigned 229 patients who had well-differentiated, metastatic midgut neuroendocrine tumors to receive either ¹⁷⁷Lu-Dotatate (116 patients) at a dose of 7.4 GBq every 8 weeks (four intravenous infusions, plus best supportive care including octreotide long-acting repeatable [LAR] administered intramuscularly at a dose of 30 mg) (¹⁷⁷Lu-Dotatate group) or octreotide LAR alone (113 patients) administered intramuscularly at a dose of 60 mg every 4 weeks (control group). The primary end point was progression-free survival. Secondary end points included the objective response rate, overall survival, safety, and the side-effect profile. The final analysis of overall survival will be conducted in the future as specified in the protocol; a prespecified interim analysis of overall survival was conducted and is reported here.

RESULTS

At the data-cutoff date for the primary analysis, the estimated rate of progression-free survival at month 20 was 65.2% (95% confidence interval [CI], 50.0 to 76.8) in the ¹⁷⁷Lu-Dotatate group and 10.8% (95% CI, 3.5 to 23.0) in the control group. The response rate was 18% in the ¹⁷⁷Lu-Dotatate group versus 3% in the control group (P<0.001). In the planned interim analysis of overall survival, 14 deaths occurred in the ¹⁷⁷Lu-Dotatate group and 26 in the control group (P=0.004). Grade 3 or 4 neutropenia, thrombocytopenia, and lymphopenia occurred in 1%, 2%, and 9%, respectively, of patients in the ¹⁷⁷Lu-Dotatate group as compared with no patients in the control group, with no evidence of renal toxic effects during the observed time frame.

CONCLUSIONS

Treatment with ¹⁷⁷Lu-Dotatate resulted in markedly longer progression-free survival and a significantly higher response rate than high-dose octreotide LAR among patients with advanced midgut neuroendocrine tumors. Preliminary evidence of an overall survival benefit was seen in an interim analysis; confirmation will be required in the planned final analysis. Clinically significant myelosuppression occurred in less than 10% of patients in the ¹⁷⁷Lu-Dotatate group. (Funded by Advanced Accelerator Applications; NETTER-1 ClinicalTrials.gov number, NCT01578239 ; EudraCT number 2011-005049-11 .).

Phase 3 Trial of 177Lu-Dotatate for Midgut Neuroendocrine Tumors

BACKGROUND

Patients with advanced midgut neuroendocrine tumors who have had disease progression during first-line somatostatin analogue therapy have limited therapeutic options. This randomized, controlled trial evaluated the efficacy and safety of lutetium-177 (¹⁷⁷Lu)-Dotatate in patients with advanced, progressive, somatostatin-receptor-positive midgut neuroendocrine tumors.

METHODS

We randomly assigned 229 patients who had well-differentiated, metastatic midgut neuroendocrine tumors to receive either ¹⁷⁷Lu-Dotatate (116 patients) at a dose of 7.4 GBq every 8 weeks (four intravenous infusions, plus best supportive care including octreotide long-acting repeatable [LAR] administered intramuscularly at a dose of 30 mg) (¹⁷⁷Lu-Dotatate group) or octreotide LAR alone (113 patients) administered intramuscularly at a dose of 60 mg every 4 weeks (control group). The primary end point was progression-free survival. Secondary end points included the objective response rate, overall survival, safety, and the side-effect profile. The final analysis of overall survival will be conducted in the future as specified in the protocol; a prespecified interim analysis of overall survival was conducted and is reported here.

RESULTS

At the data-cutoff date for the primary analysis, the estimated rate of progression-free survival at month 20 was 65.2% (95% confidence interval [CI], 50.0 to 76.8) in the ¹⁷⁷Lu-Dotatate group and 10.8% (95% CI, 3.5 to 23.0) in the control group. The response rate was 18% in the ¹⁷⁷Lu-Dotatate group versus 3% in the control group (P<0.001). In the planned interim analysis of overall survival, 14 deaths occurred in the ¹⁷⁷Lu-Dotatate group and 26 in the control group (P=0.004). Grade 3 or 4 neutropenia, thrombocytopenia, and lymphopenia occurred in 1%, 2%, and 9%, respectively, of patients in the ¹⁷⁷Lu-Dotatate group as compared with no patients in the control group, with no evidence of renal toxic effects during the observed time frame.

CONCLUSIONS

Treatment with ¹⁷⁷Lu-Dotatate resulted in markedly longer progression-free survival and a significantly higher response rate than high-dose octreotide LAR among patients with advanced midgut neuroendocrine tumors. Preliminary evidence of an overall survival benefit was seen in an interim analysis; confirmation will be required in the planned final analysis. Clinically significant myelosuppression occurred in less than 10% of patients in the ¹⁷⁷Lu-Dotatate group. (Funded by Advanced Accelerator Applications; NETTER-1 ClinicalTrials.gov number, NCT01578239 ; EudraCT number 2011-005049-11 .).

Patient-Reported Burden of a Neuroendocrine Tumor (NET) Diagnosis: Results From the First Global Survey of Patients With NETs

Purpose

Despite the considerable impact of neuroendocrine tumors (NETs) on patients’ daily lives, the journey of the patient with a NET has rarely been documented, with published data to date being limited to small qualitative studies. NETs are heterogeneous malignancies with nonspecific symptomology, leading to extensive health care use and diagnostic delays that affect survival. A large, international patient survey was conducted to increase understanding of the experience of the patient with a NET and identify unmet needs, with the aim of improving disease awareness and care worldwide.

Methods

An anonymous, self-reported survey was conducted (online or on paper) from February to May 2014, recruiting patients with NETs from > 12 countries as a collaboration between the International Neuroendocrine Cancer Alliance and Novartis Pharmaceuticals. Survey questions captured information on sociodemographics, clinical characteristics, NET diagnostic experience, disease impact/management, interaction with medical teams, NET knowledge/awareness, and sources of information. This article reports the most relevant findings on patient experience with NETs and the impact of NETs on health care system resources.

Results

A total of 1,928 patients with NETs participated. A NET diagnosis had a substantially negative impact on patients’ personal and work lives. Patients reported delayed diagnosis and extensive NET-related health care resource use. Patients desired improvement in many aspects of NET care, including availability of a wider range of NET-specific treatment options, better access to NET experts or specialist centers, and a more knowledgeable, better-coordinated/-aligned NET medical team.

Conclusion

This global patient-reported survey demonstrates the considerable burden of NETs with regard to symptoms, work and daily life, and health care resource use, and highlights considerable unmet needs. Further intervention is required to improve the patient experience among those with NETs.

Everolimus for the treatment of advanced, non-functional neuroendocrine tumours of the lung or gastrointestinal tract (RADIANT-4): a randomised, placebo-controlled, phase 3 study

BACKGROUND

Effective systemic therapies for patients with advanced, progressive neuroendocrine tumours of the lung or gastrointestinal tract are scarce. We aimed to assess the efficacy and safety of everolimus compared with placebo in this patient population.

METHODS

In the randomised, double-blind, placebo-controlled, phase 3 RADIANT-4 trial, adult patients (aged ≥18 years) with advanced, progressive, well-differentiated, non-functional neuroendocrine tumours of lung or gastrointestinal origin were enrolled from 97 centres in 25 countries worldwide. Eligible patients were randomly assigned in a 2:1 ratio by an interactive voice response system to receive everolimus 10 mg per day orally or identical placebo, both with supportive care. Patients were stratified by tumour origin, performance status, and previous somatostatin analogue treatment. Patients, investigators, and the study sponsor were masked to treatment assignment. The primary endpoint was progression-free survival assessed by central radiology review, analysed by intention to treat. Overall survival was a key secondary endpoint. This trial is registered with ClinicalTrials.gov, number NCT01524783.

FINDINGS

Between April 3, 2012, and Aug 23, 2013, a total of 302 patients were enrolled, of whom 205 were allocated to everolimus 10 mg per day and 97 to placebo. Median progression-free survival was 11·0 months (95% CI 9·2-13·3) in the everolimus group and 3·9 months (3·6-7·4) in the placebo group. Everolimus was associated with a 52% reduction in the estimated risk of progression or death (hazard ratio [HR] 0·48 [95% CI 0·35-0·67], p<0·00001). Although not statistically significant, the results of the first pre-planned interim overall survival analysis indicated that everolimus might be associated with a reduction in the risk of death (HR 0·64 [95% CI 0·40-1·05], one-sided p=0·037, whereas the boundary for statistical significance was 0·0002). Grade 3 or 4 drug-related adverse events were infrequent and included stomatitis (in 18 [9%] of 202 patients in the everolimus group vs 0 of 98 in the placebo group), diarrhoea (15 [7%] vs 2 [2%]), infections (14 [7%] vs 0), anaemia (8 [4%] vs 1 [1%]), fatigue (7 [3%] vs 1 [1%]), and hyperglycaemia (7 [3%] vs 0).

INTERPRETATION

Treatment with everolimus was associated with significant improvement in progression-free survival in patients with progressive lung or gastrointestinal neuroendocrine tumours. The safety findings were consistent with the known side-effect profile of everolimus. Everolimus is the first targeted agent to show robust anti-tumour activity with acceptable tolerability across a broad range of neuroendocrine tumours, including those arising from the pancreas, lung, and gastrointestinal tract.

FUNDING

Novartis Pharmaceuticals Corporation.

Differences and Similarities in the Clinicopathological Features of Pancreatic Neuroendocrine Tumors in China and the United States: A Multicenter Study

The presentation, pathology, and prognosis of pancreatic neuroendocrine tumors (PNETs) in Asian patients have not been studied in large cohorts. We hypothesized that the clinicopathological features of PNETs of Chinese patients might be different from those of US patients. The objectives of this study were to address whether PNETs in Chinese patients exhibit unique clinicopathological features and natural history, and can be graded and staged using the WHO/ENETS criteria. This is a retrospective review of medical records of patients with PNETs in multiple academic medical centers in China (7) and the United States (2). Tumor grading and staging were based on WHO/ENETS criteria. The clinicopathological features of PNETs of Chinese and US patients were compared. Univariate and multivariate analyses were performed to find associations between survival and patient demographics, tumor grade and stage, and other clinicopathological characteristics. A total of 977 (527 Chinese and 450 US) patients with PNETs were studied. In general, Chinese patients were younger than US patients (median age 46 vs 56 years). In Chinese patients, insulinomas were the most common (52.2%), followed by nonfunctional tumors (39.7%), whereas the order was reversed in US patients. Tumor grade distribution was similar in the 2 countries (G1: 57.5% vs 55.0%; G2: 38.5% vs 41.3%; and G3: 4.0% vs 3.7%). However, age, primary tumor size, primary tumor location, grade, and stage of subtypes of PNETs were significantly different between the 2 countries. The Chinese nonfunctional tumors were significantly larger than US ones (median size 4 vs 3 cm) and more frequently located in the head/neck region (54.9% vs 34.8%). The Chinese and US insulinomas were similar in size (median 1.5 cm) but the Chinese insulinomas relatively more frequently located in the head/neck region (48.3% vs 26.1%). Higher grade, advanced stage, metastasis, and larger primary tumor size were significantly associated with unfavorable survival in both countries. Several clinicopathological differences are found between Chinese and US PNETs but the PNETs of both countries follow a similar natural history. The WHO tumor grading and ENETS staging criteria are applicable to both Chinese and US patients.

Consensus on biomarkers for neuroendocrine tumour disease

Management of neuroendocrine neoplasia represents a clinical challenge because of its late presentation, lack of treatment options, and limitations in present imaging modalities and biomarkers to guide management. Monoanalyte biomarkers have poor sensitivity, specificity, and predictive ability. A National Cancer Institute summit, held in 2007, on neuroendocrine tumours noted biomarker limitations to be a crucial unmet need in the management of neuroendocrine tumours. A multinational consensus meeting of multidisciplinary experts in neuroendocrine tumours assessed the use of current biomarkers and defined the perquisites for novel biomarkers via the Delphi method. Consensus (at >75%) was achieved for 88 (82%) of 107 assessment questions. The panel concluded that circulating multianalyte biomarkers provide the highest sensitivity and specificity necessary for minimum disease detection and that this type of biomarker had sufficient information to predict treatment effectiveness and prognosis. The panel also concluded that no monoanalyte biomarker of neuroendocrine tumours has yet fulfilled these criteria and there is insufficient information to support the clinical use of miRNA or circulating tumour cells as useful prognostic markers for this disease. The panel considered that trials measuring multianalytes (eg, neuroendocrine gene transcripts) should also identify how such information can optimise the management of patients with neuroendocrine tumours.

Primary hepatocellular carcinoma ("hepatoid" carcinoma) of the pancreas: a case report and review of the literature

Key Clinical Message

We present a case of hepatocellular carcinoma located within the pancreas. These tumors occur in the body and tail of the pancreas, with a male predominance, and at a younger age. Tumors with pure hepatocellular histopathology have better survival and recurrence rates and should be offered surgical therapy if possible.

Small bowel carcinoid: Location isn’t everything!

AIM: To investigate the prognostic significance of the primary site of disease for small bowel carcinoid (SBC) using a population-based analysis.

METHODS: The Surveillance, Epidemiology and End Results (SEER) database was queried for histologically confirmed SBC between the years 1988 and 2009. Overall survival (OS) and disease-specific survival (DSS) were analyzed using the Kaplan-Meier method and compared using Log rank testing. Log rank and multivariate Cox regression analyses were used to identify predictors of survival using age, year of diagnosis, race, gender, tumor histology/size/location, tumor-node-metastasis stage, number of lymph nodes (LNs) examined and percent of LNs with metastases.

RESULTS: Of the 3763 patients, 51.2% were male with a mean age of 62.13 years. Median follow-up was 50 mo. The 10-year OS and DSS for duodenal primaries were significantly better when compared to jejunal and ileal primaries (P = 0.02 and < 0.0001, respectively). On multivariate Cox regression analysis, after adjusting for multiple factors, primary site location was not a significant predictor of survival (P = 0.752 for OS and P = 0.966 DSS) while age, number of primaries, number of LNs examined, T-stage and M-stage were independent predictors of survival.

CONCLUSION: This 21-year, population-based study of SBC challenges the concept that location of the primary lesion alone is a significant predictor of survival.

Single Subcutaneous Nodule as Initial Presentation of Atypical Lung Carcinoid

We report a 50-year-old woman whose atypical lung carcinoid presented as a single subcutaneous nodule. Biopsy of the nodule revealed neuroendocrine carcinoma likely from the lungs. Imaging studies revealed masses in lungs, pelvis and right axilla, and a seizure a few months later lead to discovery of brain metastasis. This case illustrates that an apparently innocuous subcutaneous nodule could be the initial presentation of an otherwise asymptomatic but widely metastatic atypical lung carcinoid. Physicians should be aware of signs of skin metastasis from lung malignancies and judiciously select patients with subcutaneous nodule for biopsy.

Precise measurement of the neutron magnetic form factor G(M)n in the few-GeV2 region

The neutron elastic magnetic form factor was extracted from quasielastic electron scattering on deuterium over the range Q;{2}=1.0-4.8 GeV2 with the CLAS detector at Jefferson Lab. High precision was achieved with a ratio technique and a simultaneous in situ calibration of the neutron detection efficiency. Neutrons were detected with electromagnetic calorimeters and time-of-flight scintillators at two beam energies. The dipole parametrization gives a good description of the data.

Search for the photoexcitation of exotic mesons in the pi+pi+pi- system

A search for exotic mesons in the pi;{+}pi;{+}pi;{-} system photoproduced by the charge exchange reaction gammap-->pi;{+}pi;{+}pi;{-}(n) was carried out by the CLAS Collaboration at Jefferson Lab. A tagged-photon beam with energies in the 4.8 to 5.4 GeV range, produced through bremsstrahlung from a 5.744 GeV electron beam, was incident on a liquid-hydrogen target. A partial wave analysis was performed on a sample of 83 000 events, the highest such statistics to date in this reaction at these energies. The main objective of this study was to look for the photoproduction of an exotic J;{PC}=1;{-+} resonant state in the 1 to 2 GeV mass range. Our partial wave analysis shows production of the a_{2}(1320) and the pi_{2}(1670) mesons, but no evidence for the a_{1}(1260), nor the pi_{1}(1600) exotic state at the expected levels. An upper limit of 13.5 nb is determined for the exotic pi_{1}(1600) cross section, less than 2% of the a_{2}(1320) production.

Measurement of direct f0(980) photoproduction on the proton

We report on the results of the first measurement of exclusive f_{0}(980) meson photoproduction on protons for E_{gamma}=3.0-3.8 GeV and -t=0.4-1.0 GeV2. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. The resonance was detected via its decay in the pi;{+}pi;{-} channel by performing a partial wave analysis of the reaction gammap-->ppi;{+}pi;{-}. Clear evidence of the f_{0}(980) meson was found in the interference between P and S waves at M_{pi;{+}pi;{-}} approximately 1 GeV. The S-wave differential cross section integrated in the mass range of the f_{0}(980) was found to be a factor of about 50 smaller than the cross section for the rho meson. This is the first time the f_{0}(980) meson has been measured in a photoproduction experiment.

Measurement of deeply virtual compton scattering beam-spin asymmetries

The beam-spin asymmetries in the hard exclusive electroproduction of photons on the proton (e p-->epgamma) were measured over a wide kinematic range and with high statistical accuracy. These asymmetries result from the interference of the Bethe-Heitler process and of deeply virtual Compton scattering. Over the whole kinematic range (x(B) from 0.11 to 0.58, Q2 from 1 to 4.8 GeV2, -t from 0.09 to 1.8 GeV2), the azimuthal dependence of the asymmetries is compatible with expectations from leading-twist dominance, A approximately a sinphi/(1+c cosphi). This extensive set of data can thus be used to constrain significantly the generalized parton distributions of the nucleon in the valence quark sector.

Bayesian analysis of pentaquark signals from CLAS data

We examine the results of two measurements by the CLAS collaboration, one of which claimed evidence for a Theta(+) pentaquark, while the other found no such evidence. The unique feature of these two experiments was that they were performed with the same experimental setup. Using a Bayesian analysis, we find that the results of the two experiments are in fact compatible with each other, but that the first measurement did not contain sufficient information to determine unambiguously the existence of a Theta(+). Further, we suggest a means by which the existence of a new candidate particle can be tested in a rigorous manner.

Search for medium modifications of the rho meson

The photoproduction of vector mesons on various nuclei has been studied using the CLAS detector at Jefferson Laboratory. The vector mesons, rho, omega, and varphi, are observed via their decay to e;{+}e;{-}, in order to reduce the effects of final-state interactions in the nucleus. Of particular interest are possible in-medium effects on the properties of the rho meson. The rho mass spectrum is extracted from the data on various nuclei, 2H, C, Fe, and Ti. We observe no significant mass shift and some broadening consistent with expected collisional broadening for the rho meson.

Experimental study of exclusive 2H(e,e'p)n reaction mechanisms at high Q2

The reaction 2H(e,e'p)n has been studied with full kinematic coverage for photon virtuality 1.75<Q2<5.5 GeV2. Comparisons of experimental data with theory indicate that for very low values of neutron recoil momentum (p(n)<100 MeV/c) the neutron is primarily a spectator and the reaction can be described by the plane-wave impulse approximation. For 100<p(n)<750 MeV/c, proton-neutron rescattering dominates the cross section, while Delta production followed by the NDelta-->NN transition is the primary contribution at higher momenta.

Measurement of the N-->Delta(+)(1232) transition at high-momentum transfer by pi(0) electroproduction

We report a new measurement of the exclusive electroproduction reaction gamma(*)p-->pi(0)p to explore the evolution from soft nonperturbative physics to hard processes via the Q(2) dependence of the magnetic (M(1+)), electric (E(1+)), and scalar (S(1+)) multipoles in the N-->Delta transition. 9000 differential cross section data points cover W from threshold to 1.4 GeV/c(2), 4pi center-of-mass solid angle, and Q(2) from 3 to 6 GeV(2)/c(2), the highest yet achieved. It is found that the magnetic form factor G(M)(*) decreases with Q(2) more steeply than the proton magnetic form factor, the ratio E(1+)/M(1+) is small and negative, indicating strong helicity nonconservation, and the ratio S(1+)/M(1+) is negative, while its magnitude increases with Q(2).

Search for Theta++ pentaquarks in the exclusive reaction gammap-->K+K-p

The reaction gammap --> pK+K- was studied at Jefferson Lab with photon energies from 1.8 to 3.8 GeV using a tagged photon beam. The goal was to search for a Theta++ pentaquark, a narrow, doubly charged baryon state having strangeness S=+1 and isospin I=1, in the pK+ invariant mass spectrum. No statistically significant evidence of a Theta++ was found. Upper limits on the total and differential cross section for the reaction gammap --> K-Theta++ were obtained in the mass range from 1.5 to 2.0 GeV/c2, with an upper limit for a narrow resonance with a mass M(Theta++) = 1.54 GeV/c2 of about 0.15 nb, 95% C.L.. This result places a stringent upper limit on the Theta++ width Gamma(Theta++) <0.1 MeV/c2.

Measurement of deeply virtual compton scattering with a polarized-proton target

The longitudinal target-spin asymmetry AUL for the exclusive electroproduction of high-energy photons was measured for the first time in ep-->e;'pgamma. The data have been accumulated at JLab with the CLAS spectrometer using 5.7 GeV electrons and a longitudinally polarized NH3 target. A significant azimuthal angular dependence was observed, resulting from the interference of the deeply virtual Compton scattering and Bethe-Heitler processes. The amplitude of the sinvarphi moment is 0.252+/-0.042stat+/-0.020sys. Theoretical calculations are in good agreement with the magnitude and the kinematic dependence of the target-spin asymmetry, which is sensitive to the generalized parton distributions H and H.

Search for the Theta+ Pentaquark in the gammad--> DeltanK+ reaction measured with the CLAS spectrometer

For the first time, the reaction gammad-->DeltanK+ has been analyzed in order to search for the exotic pentaquark baryon Theta+(1540). The data were taken at Jefferson Laboratory, using the Hall-B tagged-photon beam of energy between 0.8 and 3.6 GeV and the CEBAF Large Acceptance Spectrometer (CLAS). No statistically significant structures were observed in the nK+ invariant-mass distribution. The upper limit on the gammad-->DeltaTheta+ integrated cross section has been calculated and found to be between 5 and 25 nb, depending on the production model assumed. The upper limit on the differential cross section is also reported.

Search for the Theta+ pentaquark in the reaction gammad --> pK-K+n

A search for the Theta+ in the reaction gammad --> pK-K+n was completed using the CLAS detector at Jefferson Lab. A study of the same reaction, published earlier, reported the observation of a narrow Theta+ resonance. The present experiment, with more than 30 times the integrated luminosity of our earlier measurement, does not show any evidence for a narrow pentaquark resonance. The angle-integrated upper limit on Theta+ production in the mass range of 1.52-1.56 GeV/c2 for the gammad --> pK-Theta+ reaction is 0.3 nb (95% C.L.). This upper limit depends on assumptions made for the mass and angular distribution of Theta+ production. Using Lambda(1520) production as an empirical measure of rescattering in the deuteron, the cross section upper limit for the elementary gamman --> K-Theta+ reaction is estimated to be a factor of 10 higher, i.e., approximately 3 nb (95% C.L.).

Measurement of two- and three-nucleon short-range correlation probabilities in nuclei

The ratios of inclusive electron scattering cross sections of 4He, 12C, and 56Fe to 3He have been measured at 1 < xB <. At Q2 > 1.4 GeV2, the ratios exhibit two separate plateaus, at 1.5 < xB < 2 and at xB > 2.25. This pattern is predicted by models that include 2- and 3-nucleon short-range correlations (SRC). Relative to A = 3, the per-nucleon probabilities of 3-nucleon SRC are 2.3, 3.1, and 4.4 times larger for A = 4, 12, and 56. This is the first measurement of 3-nucleon SRC probabilities in nuclei.