Weight Maintenance up to 48 Weeks in Patients With Carcinoid Syndrome Treated With Telotristat Ethyl: Pooled Data From the Open-Label Extensions of the Phase III Clinical Trials TELESTAR and TELECAST

Reported incidences of neuroendocrine tumors (NETs) appear to be increasing, possibly due to greater disease awareness and increased accuracy of diagnosis. Approximately 20% of patients with NETs develop carcinoid syndrome (CS), which arises from elevated secretion of bioactive compounds, including serotonin, from NETs. This leads to symptoms including diarrhea and flushing, which result in weight loss and are associated with considerable negative impact on patients' quality of life. We previously reported significant weight gain and improved nutritional status in patients with NETs who were treated with telotristat ethyl (TE) for 12 weeks. In this follow-up analysis, using pooled data from the 36-week open-label extensions of the TELESTAR (NCT01677910) and TELECAST (NCT02063659) phase III trials, we demonstrate that improvements in weight and nutritional parameters were sustained or further improved in patients with CS through to week 48 of treatment with TE. At week 48/end of study, 68.7% of all patients maintained a stable weight or had weight gain and the mean changes from baseline in cholesterol and albumin levels in patients treated with TE were +0.41 mmol/L and -0.34 g/L, respectively. These results indicate that TE, alongside routine clinical practice, may provide long-term benefits in nutritional intake and weight evolution in patients with CS.

Use Of Temozolomide In Parathyroid Carcinoma With Negative Mgmt Promoter Methylation

Introduction: Parathyroid carcinoma (PC) is a rare malignancy with a high rate of recurrence and metastasis. Case: A 63-year-old man with a 13-year history of recurrent PC requiring 5 operations, including parathyroidectomies, thyroidectomy, and neck dissections presented with polyuria, polydipsia, and worsening rib pain. He had been recently treated with 6 monthly octreotide injections and maximal dose cinacalcet for gradually rising Ca/PTH levels. Tests revealed serum Ca 13.1mg/dL (8-10.5mg/dL), PTH 1750pg/mL (11-90 pg/mL), and serum Cr 3.34mg/dL (0.5-1.3mg/dL). Imaging identified tumor in the right 6^th rib (3.6cm lytic lesion), and soft tissue lesions in the left thyroid bed (3 masses, the largest 1.6cm) and the suprasternal notch (1.1cm). He underwent rib resection (metastasectomy) and PTH declined from 2334pg/mL to 671pg/mL. Although metastasectomy improved the PTH level, Ca levels began to rise from the residual tumor. A multidisciplinary team deemed the risk of complications from repeat neck surgery to be prohibitively high. Temozolomide (TEM) (150-200mg/m2/d x 5d, q28d) was instituted 3 months after the rib resection. 13 months later, PTH has stably ranged from 600-800 pg/mL with a normal serum Ca of 9.8mg/dL. Recent imaging shows stable disease in the neck, without distant disease. Discussion: The mainstay of therapy for initial and recurrent/metastatic PC is surgery. Inoperable disease has a poor prognosis because of lack of effective systemic therapies. Radiation and chemotherapy have not shown much efficacy. Results of treatment with octreotide have not been encouraging. Anti-PTH immunotherapy and Lutathera are promising but require further investigation. Usually, no targetable mutation is found. Anti-angiogenic TKI’s (sorafenib, lenvatinib) have been used with varying success. An exciting therapy used in this patient is TEM, an alkylating agent used for CNS tumors, neuroendocrine tumors (NET) and aggressive pituitary tumors. A previous report described successful use of TEM in a case of metastatic PC, whose tumor harbored high O6-methylguanine DNA methyltransferase (MGMT) promoter methylation status, a known predictor of positive response in CNS tumors. Promoter methylation is an epigenetic alteration that leads to low MGMT enzyme activity & enhances the cytotoxicity of TEM. Some studies in NET demonstrated tumor response irrespective of MGMT status. This leads to the question of whether the same is true in PC. Our patient has radiographic/biochemical stable disease on TEM, and a surprising retrospective discovery was that the MGMT promoter was unmethylated. This is a unique case of PC which seems to be responding to TEM despite absent promoter methylation. Further studies are warranted, as the incidence of PC is rising over the past decades. In the interim, clinicians could consider using TEM for in-operable PC irrespective of MGMT methylation status.

Recurrence Patterns After Surgical Resection of Gastroenteropancreatic Neuroendocrine Tumors: Analysis From the National Comprehensive Cancer Network Oncology Outcomes Database

OBJECTIVE

Current National Comprehensive Cancer Network guidelines for gastroenteropancreatic neuroendocrine tumors (GEPNETs) recommend complete (R0) surgical resection of the primary tumor and metastases, if feasible. However, large multicenter studies of recurrence patterns of GEPNETs after resection have not been performed.

METHODS

Patients 18 years or older who presented to 7 participating National Comprehensive Cancer Network institutions between 2004 and 2008 with a new diagnosis of a small bowel, pancreas, or colon/rectum neuroendocrine tumor (NET) and underwent R0 resection of the primary tumor, and synchronous metastases, if present, were included in this analysis. Descriptive statistics and Kaplan-Meier estimates were used to calculate recurrence rates and time-associated end points, respectively.

RESULTS

Of 294 patients with GEPNETs, 50% were male, 88% were White, and 99% had Eastern Cooperative Oncology Group performance status 0 to 1. The median age was 55 years (range, 20-90). The median follow-up time from R0 resection was 62.1 months. Recurrence rates were 18% in small bowel NETs (n = 110), 26% in pancreatic NETs (n = 141), and 10% in colon/rectum NETs (n = 50). The frequency of surveillance imaging was highly variable.

CONCLUSIONS

R0 resection was associated with variable risk of recurrence across subtypes. Further research to inform refinement of guidelines for the appropriate duration of surveillance after R0 resection is needed.

Updated Efficacy and Safety Outcomes for Patients with Well-Differentiated Pancreatic Neuroendocrine Tumors Treated with Sunitinib

BACKGROUND

Sunitinib prolonged progression-free survival (PFS) versus placebo in patients with metastatic pancreatic neuroendocrine tumors (panNETs) in a phase III trial. The efficacy and safety of sunitinib in patients with panNETs were confirmed in an open-label phase IV trial.

OBJECTIVE

To assess the clinical benefit with sunitinib using the combined data from these trials.

PATIENTS AND METHODS

An updated overall survival (OS) in patients with panNETs for the phase IV trial was provided, and an analysis of results from the sunitinib-treated combined cohort from the phase III and IV trials (combined cohort) was conducted to assess PFS, OS, and objective response rate (ORR).

RESULTS

The updated median OS for the phase IV trial was 54.1 months (95% CI 37.9-not reached). Investigator-assessed median PFS for the combined cohort (n = 102) was 12.9 months (95% CI 7.4-16.7) with a significant benefit versus placebo in the phase III trial (n = 35) (HR 0.429; 95% CI 0.245-0.752; p = 0.001). Median OS could not be calculated for the combined cohort or placebo group due to the high number of patients censored; however, the estimated HR of 0.303 (CI 0.100-0.921; p = 0.013) favored sunitinib. ORR for the combined cohort was 16.7% (95% CI 10.0-25.3). Sunitinib was well tolerated in both trials with a safety profile similar to previously seen in other studies.

CONCLUSIONS

The combined analysis of these studies confirms the objective tumor responses and improvements in PFS observed in the initial phase III trial, providing further support for the clinical benefit of sunitinib in patients with advanced panNETs. CLINICALTRIALS.

GOV IDENTIFIERS

NCT00428597 and NCT01525550.

Multicohort Retrospective Validation of a Predictive Biomarker for Topoisomerase I Inhibitors

PURPOSE

The camptothecin (CPT) analogs topotecan and irinotecan specifically target topoisomerase I (topoI) and are used to treat colorectal, gastric, and pancreatic cancer. Response rate for this class of drug varies from 10% to 30%, and there is no predictive biomarker for patient stratification by response. On the basis of our understanding of CPT drug resistance mechanisms, we developed an immunohistochemistry-based predictive test, P-topoI-Dx, to stratify the patient population into those who did and did not experience a response.

PATIENTS AND METHODS

The retrospective validation studies included a training set (n = 79) and a validation cohort (n = 27) of gastric cancer (GC) patients, and 8 cohorts of colorectal cancer (CRC) patient tissue (n = 176). Progression-free survival for 6 months was considered a positive response to CPT-based therapy. Formalin-fixed, paraffin-embedded slides were immunohistochemically stained with anti-phospho-specific topoI-Serine10 (topoI-pS10), quantitated, and analyzed statistically.

RESULTS

We determined a threshold of 35% positive staining to offer optimal test characteristics in GC. The GC (n = 79) training set demonstrated 76.6% (95% confidence interval, 64-86) sensitivity; 68.8% (41-88) specificity; positive predictive value (PPV) 92.5% (81-98); and negative predictive value (NPV) 42.3% (24-62). The GC validation set (n = 27) demonstrated 82.4% (56-95) sensitivity and 70.0% (35-92) specificity. Estimated PPV and NPV were 82.4% (56-95) and 70.0% (35-92) respectively. In the CRC validation set (n = 176), the 40% threshold demonstrated 87.5% (78-94) sensitivity; 70.0% (59-79) specificity; PPV 70.7% (61-79); and NPV 87.0 % (77-93).

CONCLUSION

The analysis of retrospective data from patients (n = 282) provides clinical validity to our P-topoI-Dx immunohistochemical test to identify patients with disease that is most likely to respond to topoI inhibitors.

Evaluation of meaningful change in bowel movement frequency for patients with carcinoid syndrome

Background

Carcinoid syndrome is associated with a reduced quality of life that can be attributed to symptoms such as diarrhea and fatigue as well as social and financial issues. This study was conducted to psychometrically assess meaningful change in bowel movement frequency among carcinoid syndrome patients using data from the TELESTAR clinical study.

Methods

An anchor-based approach for deriving meaningful change thresholds consisted of mapping change from baseline bowel movement frequency to other patient-reported assessments of change. These included the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire - Core Questionnaire (QLQ-C30) Diarrhea Symptom responders, the EORTC Gastrointestinal NET questionnaire (GI.NET21) GI Symptom responders, and reported adequate relief at Week 12 (≥ 10-point score decrease from Day 1 to Week 12). Parameters included within-group mean change from baseline to Week 12, t-tests of the change (Wilcoxon rank sum for adequate relief), and effect size.

Results

There were 135 carcinoid syndrome patients with a mean baseline frequency of 5.7 bowel movements a day. A distribution-based method yielded meaningful change estimates of 0.62 bowel movements a day for overall frequency and 0.83 bowel movements a day at Week 12. Anchor-based analysis indicated a large effect size among patients who reported adequate relief at Week 12 (− 1.58; n = 18; P = 0.014), the QLQ-C30 Diarrhea domain responders (− 1.24; n = 40; P < 0.001), and the GI.NET21 GI Symptoms Domain responders (− 1.49; n = 25; P = 0.005). Exit interview data for meaningful change yielded effect size estimates of − 1.57 for overall change during the Double-blind Treatment Period and − 1.97 for change between Baseline and Week 12.

Conclusions

Meaningful change derivation is critical to interpret patient outcomes for evaluating treatment efficacy. In this study, carcinoid syndrome patients experienced clinically meaningful reductions in bowel movement frequency of ≥30% over 12 weeks with telotristat ethyl treatment.

Trial registration

NCT01677910.

Pharmacogenomic analyses of sunitinib in patients with pancreatic neuroendocrine tumors

Aim: Evaluate associations between clinical outcomes and SNPs in patients with well-differentiated pancreatic neuroendocrine tumors receiving sunitinib. Patients & methods: Kaplan–Meier and Cox proportional hazards models were used to analyze the association between SNPs and survival outcomes using data from a sunitinib Phase IV (genotyped, n = 56) study. Fisher’s exact test was used to analyze objective response rate and genotype associations. Results: After multiplicity adjustment, progression-free and overall survivals were not significantly correlated with SNPs; however, a higher objective response rate was significantly associated with IL1B rs16944 G/A versus G/G (46.4 vs 4.5%; p = 0.001). Conclusion: IL1B SNPs may predict treatment response in patients with pancreatic neuroendocrine tumors. VEGF pathway SNPs are potentially associated with survival outcomes.

Enhanced detection of microsatellite instability using pre-PCR elimination of wild-type DNA homo-polymers in tissue and liquid biopsies

Detection of microsatellite-instability in colonoscopy-obtained polyps, as well as in plasma-circulating DNA, is frequently confounded by sensitivity issues due to co-existing excessive amounts of wild-type DNA. While also an issue for point mutations, this is particularly problematic for microsatellite changes, due to the high false-positive artifacts generated by polymerase slippage (stutter-bands). Here, we describe a nuclease-based approach, NaME-PrO, that uses overlapping oligonucleotides to eliminate unaltered micro-satellites at the genomic DNA level, prior to PCR. By appropriate design of the overlapping oligonucleotides, NaME-PrO eliminates WT alleles in long single-base homopolymers ranging from 10 to 27 nucleotides in length, while sparing targets containing variable-length indels at any position within the homopolymer. We evaluated 5 MSI targets individually or simultaneously, NR27, NR21, NR24, BAT25 and BAT26 using DNA from cell-lines, biopsies and circulating-DNA from colorectal cancer patients. NaME-PrO enriched altered microsatellites and detected alterations down to 0.01% allelic-frequency using high-resolution-melting, improving detection sensitivity by 500-1000-fold relative to current HRM approaches. Capillary-electrophoresis also demonstrated enhanced sensitivity and enrichment of indels 1-16 bases long. We anticipate application of this highly-multiplex-able method either with standard 5-plex reactions in conjunction with HRM/capillary electrophoresis or massively-parallel-sequencing-based detection of MSI on numerous targets for sensitive MSI-detection.

Abstract 942: Sensitive detection of microsatellite instability (MSI) in tumors and liquid biopsies using nuclease-based enrichment

The role of MSI in colorectal cancer (CRC) is well characterized, and colon tumors are classified as MSI-High or MSI-Stable by screening specific microsatellites. MSI-H compared to MSI-S is predictive for therapy outcome in chemotherapy and immunotherapy and has been associated with distinct characteristics and favorable results including better prognosis, a higher 5-year survival, and lesser metastasis. Several other tumors also present MSI changes reflecting mismatch repair deficiency. While tumor testing is the gold standard, a convenient approach to screen for MSI before and during cancer treatment is screening circulating DNA (liquid biopsy) using a blood draw, thereby interrogating ‘systemic' MSI reflecting primary or secondary (occult) tumor status at the time of blood collection. However, presence of excess unaltered, wild-type DNA often masks alterations such as MSI. Using capillary electrophoresis or next generation sequencing for MSI detection presents challenges at low levels of MSI due to polymerase slippage (‘stutter') that generate high false positive rates at positions of homo-polymers. We present a new approach for enrichment of altered micro-satellites prior to DNA-amplification thereby facilitating their detection. We recently developed nuclease-assisted minor-allele enrichment with probe-overlap, a single-step approach that removes WT-DNA and enriches mutation-containing alleles. Here we adapted NaME-PrO for detection of homopolymer indels, for MSI detection. The method employs a double-strand-DNA-specific nuclease and overlapping oligonucleotide-probes interrogating multiple micro-satellite targets. Following DNA denaturation, the probes form double-stranded regions with their targets, thereby guiding nuclease digestion to selected sites. Microsatellite indels create ‘bulges' that inhibit digestion, thus subsequent amplification yields DNA with microsatellite alterations enhanced at multiple targets. The assay is applied at the genomic or circulating-DNA level prior to amplification, thereby avoiding polymerase-introduced ‘stutter peaks' arising from WT DNA. Inclusion of organic solvents allows homogeneous application of the method in closed tube reactions. We validated the method by evaluating 5 MSI targets simultaneously, NR27, NR21, NR24, BAT25 and BAT26 using DNA from tumor biopsies and circulating-DNA from colorectal cancer patients. The technique enriched all altered targets and detected microsatellite alterations down to 0.01% altered allele frequency, thus improving detection sensitivity by &gt;100-fold relative to current approaches. We anticipate application of this highly- multiplex-able method either with standard 5-plex reactions in conjunction with capillary electrophoresis or with NGS-based detection of MSI on thousands of targets to enable sensitive detection in tumors and liquid biopsies.

Citation Format: Ioannis Ladas, Chen Song, Fangyan Yu, Ka Wai Leong, Katerina Troullinou, Matthew Kulke, Harvey Mamon, Mike G. Makrigiorgos. Sensitive detection of microsatellite instability (MSI) in tumors and liquid biopsies using nuclease-based enrichment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 942.

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.

ENETS Consensus Guidelines for the Standards of Care in Neuroendocrine Neoplasms. Systemic Therapy 2: Chemotherapy

Systemic chemotherapy is indicated in progressive or bulky advanced pancreatic neuroendocrine tumors (NETs) and in grade 3 (G3) neuroendocrine neoplasms (NENs) as per ENETS guidelines. Chemotherapy may be considered in NETs of other sites (lung, thymus, stomach, colon, and rectum) under certain conditions (e.g., when Ki-67 is at a high level [upper G2 range], in rapidly progressive disease and/or after failure of other therapies, or if somatostatin receptor imaging is negative). An ENETS Consensus Conference was held in Antibes (2015) to elaborate guidelines on the standards of care of different diagnostic procedures and therapeutic interventions in NENs. This article provides guidance on chemotherapy including therapeutic indications, dosing schedules, adverse events (including prevention and management), drug interactions, and evaluation of treatment effect for the chemotherapy agents most commonly used in NENs (streptozocin, dacarbazine, fluoropyrimidines, platinum compounds, etoposide, and irinotecan).

ENETS Consensus Guidelines for the Standards of Care in Neuroendocrine Tumors: Pathology: Diagnosis and Prognostic Stratification

The European Neuroendocrine Tumor Society (ENETS) proposed standard of care guidelines for pathology in 2009. Since then, profound changes in the classification have been made, dividing neuroendocrine neoplasia (NEN) into well-differentiated neuroendocrine tumors (NET) and poorly differentiated neuroendocrine carcinomas (NEC) in the 2010 WHO classification. The 7th edition of the TNM classification (2009) included NEN for the first time, widely adapting ENETS proposals but with some differences for NEC and for NET of the pancreas and the appendix. Therapy guidelines for gastroenteropancreatic NET were updated in 2016. The need for an update of the standards of care prompted the ENETS to organize a consensus conference which was held in Antibes in 2015; a working group was designated to propose pathological standards of care.

ENETS Consensus Guidelines for the Standards of Care in Neuroendocrine Neoplasms: Systemic Therapy - Biotherapy and Novel Targeted Agents

Systemic therapies established in the management of patients with neuroendocrine tumors (NETs) include somatostatin analogs and interferon-α, also referred to as biotherapy. Recent randomized controlled studies have extended the knowledge on the frequency of side effects associated with biotherapy. More recently, novel targeted drugs, such as the mammalian target of rapamycin inhibitor everolimus and the multiple tyrosine kinase inhibitor sunitinib, have been introduced in the management of NETs. Although targeted drugs are generally well tolerated, with most adverse events being of mild to moderate severity and manageable, novel targeted drugs exhibit a distinct adverse event profile that warrants guidance for appropriate diagnostic and therapeutic management. This is particularly important given the widespread and potentially long-term use of everolimus in a broad spectrum of NETs and of sunitinib in pancreatic NETs. This review will focus on the most relevant toxicities associated with biotherapy and novel targeted drugs and on their management. For each drug class indication, administration and dosing schedule, most frequent adverse events, actions and dose adjustments for adverse events as well as their monitoring are presented. This review further covers the evaluation of treatment effect, patient information, drug interactions, and information on pregnancy.

Abstract A53: ADAM12 contributes to the malignant potential of pancreatic cancer and may serve as a non-invasive biomarker for its detection

Pancreatic malignancies are the fourth leading cause of all cancer-related deaths of both men and women in the United States. A majority of patients with pancreatic ductal adenocarcinoma (PDAC) and pancreatic neuroendocrine tumors (pNET) present with advanced disease due to a lack of specific symptoms. The high mortality rate associated with pancreatic cancer can be attributed to both a lack of clinical diagnostic tests for early detection as well as an inadequate understanding of the underlying molecular mechanisms of its aggressive pathogenesis. We have recently become interested in the role that ADAM12 (a disintegrin and metalloprotease 12), a member of the disintegrin metalloprotease family, may play in the development and progression of pancreatic cancer. We have found that ADAM12 protein levels are significantly upregulated in human pancreatic cancer and in mouse models of PDAC and correlate with disease progression. ADAM12 levels were also upregulated in precursor PanIN lesions in a transgenic mouse model. ADAM12 transcript and protein expression is higher in poorly differentiated/quasi-mesenchymal pancreatic cancer cell lines such as Panc1 and MiaPaca2 compared to well-differentiated/classical cell lines such as AspC1 and BxPC3. Downregulation of ADAM12 in pancreatic tumor cells resulted in reduced cell migration, invasion and proliferation whereas apoptotic rates were significantly higher. In agreement with these findings, activation of common signaling pathways including pEGFR, pSTAT3 and pErk were also downregulated in response to ADAM12 silencing in these cells. We have also determined whether ADAM12 could be detected in the urine of patients with pancreatic malignancies and whether ADAM12 levels might serve as an independent predictor of disease status. Retrospective analyses of urine samples (n=130) from PDAC and pNET patients as well as age- and sex-matched controls were conducted. Urinary ADAM12 levels were determined using a monospecific ELISA system. Multivariable logistic regression analyses indicated that, when controlling for age and sex, urinary ADAM12 could serve as significant independent predictor for distinguishing PDAC (P&lt;0.001) and pNET (P&lt;0.008) patients from healthy controls. Kaplan-Meier analysis of estimated patient survival stratified by urinary ADAM12 levels indicated a significantly shorter patient survival time for PDAC patients with high ADAM12 levels (P=0.015) compared to patients with lower urinary ADAM12. Taken together, our results indicate that ADAM12 is aberrantly upregulated in PDAC tumors and contributes to the malignant properties of pancreatic tumor cells. These data also support the conclusion that the measurement of ADAM12 levels may have diagnostic value in detection and/or clinical monitoring of disease status in patients with pancreatic malignancies. [Supported by: The Advanced Medical Research Foundation]

Citation Format: Roopali Roy, Adelle Dagher, David Zurakowski, Matthew Kulke, Marsha A. Moses.{Authors}. ADAM12 contributes to the malignant potential of pancreatic cancer and may serve as a non-invasive biomarker for its detection. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr A53.

A Delphic consensus assessment: imaging and biomarkers in gastroenteropancreatic neuroendocrine tumor disease management

The complexity of the clinical management of neuroendocrine neoplasia (NEN) is exacerbated by limitations in imaging modalities and a paucity of clinically useful biomarkers. Limitations in currently available imaging modalities reflect difficulties in measuring an intrinsically indolent disease, resolution inadequacies and inter-/intra-facility device variability and that RECIST (Response Evaluation Criteria in Solid Tumors) criteria are not optimal for NEN. Limitations of currently used biomarkers are that they are secretory biomarkers (chromogranin A, serotonin, neuron-specific enolase and pancreastatin); monoanalyte measurements; and lack sensitivity, specificity and predictive capacity. None of them meet the NIH metrics for clinical usage. A multinational, multidisciplinary Delphi consensus meeting of NEN experts (n = 33) assessed current imaging strategies and biomarkers in NEN management. Consensus (>75%) was achieved for 78% of the 142 questions. The panel concluded that morphological imaging has a diagnostic value. However, both imaging and current single-analyte biomarkers exhibit substantial limitations in measuring the disease status and predicting the therapeutic efficacy. RECIST remains suboptimal as a metric. A critical unmet need is the development of a clinico-biological tool to provide enhanced information regarding precise disease status and treatment response. The group considered that circulating RNA was better than current general NEN biomarkers and preliminary clinical data were considered promising. It was resolved that circulating multianalyte mRNA (NETest) had clinical utility in both diagnosis and monitoring disease status and therapeutic efficacy. Overall, it was concluded that a combination of tumor spatial and functional imaging with circulating transcripts (mRNA) would represent the future strategy for real-time monitoring of disease progress and therapeutic efficacy.

Prognostic Impact of Novel Molecular Subtypes of Small Intestinal Neuroendocrine Tumor

PURPOSE

Small intestinal neuroendocrine tumors (SINET) are the commonest malignancy of the small intestine; however, underlying pathogenic mechanisms remain poorly characterized. Whole-genome and -exome sequencing has demonstrated that SINETs are mutationally quiet, with the most frequent known mutation in the cyclin-dependent kinase inhibitor 1B gene (CDKN1B) occurring in only ∼8% of tumors, suggesting that alternative mechanisms may drive tumorigenesis. The aim of this study is to perform genome-wide molecular profiling of SINETs in order to identify pathogenic drivers based on molecular profiling. This study represents the largest unbiased integrated genomic, epigenomic, and transcriptomic analysis undertaken in this tumor type.

EXPERIMENTAL DESIGN

Here, we present data from integrated molecular analysis of SINETs (n = 97), including whole-exome or targeted CDKN1B sequencing (n = 29), HumanMethylation450 BeadChip (Illumina) array profiling (n = 69), methylated DNA immunoprecipitation sequencing (n = 16), copy-number variance analysis (n = 47), and Whole-Genome DASL (Illumina) expression array profiling (n = 43).

RESULTS

Based on molecular profiling, SINETs can be classified into three groups, which demonstrate significantly different progression-free survival after resection of primary tumor (not reached at 10 years vs. 56 months vs. 21 months, P = 0.04). Epimutations were found at a recurrence rate of up to 85%, and 21 epigenetically dysregulated genes were identified, including CDX1 (86%), CELSR3 (84%), FBP1 (84%), and GIPR (74%).

CONCLUSIONS

This is the first comprehensive integrated molecular analysis of SINETs. We have demonstrated that these tumors are highly epigenetically dysregulated. Furthermore, we have identified novel molecular subtypes with significant impact on progression-free survival.

Baseline demographics of the randomized, placebo-controlled, double-blind, phase III RADIANT-4 study of everolimus in nonfunctional gastrointestinal (GI) or lung neuroendocrine tumors (NET)

276

Background: NET are malignant tumors arising from neuroendocrine cells throughout the body. Everolimus (EVE), a mammalian target of rapamycin inhibitor, is approved for the treatment of advanced, well-differentiated pancreatic NET. There is an unmet medical need in GI and lung NET; targeted therapies, such as everolimus, are of particular interest. Methods: Patients with advanced nonfunctional NET of GI or lung origin with progressive disease (PD) within the past 6 months were randomized (2:1) to EVE 10 mg/d or placebo, both with best supportive care. Concomitant use of somatostatin analogue (SSA) was not allowed during the study, except for control of emergent carcinoid symptoms not manageable by standard therapy. Patients were stratified based on tumor sites, prior SSA exposure, and WHO performance status (PS) at baseline. Primary endpoint was progression-free survival (PFS) as assessed by central radiology review using modified RECIST 1.0 criteria. Primary analysis is planned after ~176 PFS events. Crossover to open label EVE after progression would not be allowed prior to the primary analysis. Overall survival was the key secondary endpoint. Results: Recruitment is completed. Of 388 patients screened, 302 were randomized (planned, 285). Median age was 63 years, 53% were females, and majority of them (76.2%) were white. The most common tumor sites were lung (29.8%), ileum (23.5%), and rectum (13.2%). WHO PS was 0 in 219 (72.5%) patients and 1 in 82 (27.2%) patients; 52% had received SSA prior to study entry. As of Sep 16, 2013, 173 (57.3%) patients remain on treatment, 127 (42.1%) discontinued treatment and 2 (0.7%) were not treated. PD (24.2%) and adverse events (10.6%) were the most common reasons for treatment discontinuation. Results of primary analysis are expected by early 2015. Conclusions: RADIANT-4 is the first phase III study to assess the efficacy and safety of EVE in patients with nonfunctional NET of GI or lung origin. Non-crossover design and prospective stratification of the population based on known prognostic factors should minimize confounding in the estimation of the treatment effect. Clinical trial information: NCT01524783.

Abstract 891: Urinary ADAM12 levels detect the presence of pancreatic cancer

Pancreatic malignancies are the fourth leading cause of all cancer-related deaths of both men and women in the United States. Each year, approximately 32,000 new patients are diagnosed with this disease and nearly the same number die from it. A majority of patients with pancreatic malignancies, including both pancreatic ductal adenocarcinoma (PDAC) and pancreatic neuroendocrine tumors (pNET) present with advanced disease due to a lack of specific symptoms and current diagnostic limitations, making this disease extremely difficult to detect. The combination of poor prognosis and late presentation of pancreatic cancer patients highlights the urgent need for the development of effective, early detection strategies for this disease. Our laboratory has established a comprehensive biomarker discovery initiative whose objective is to identify proteins present in urine of cancer patients, to determine whether their presence might be relevant to disease status and stage and to validate their diagnostic and prognostic efficacy in large scale clinical trials. In the current study, our goal was to determine whether ADAM12 (a disintegrin and metalloprotease 12) could be detected in the urine of patients with pancreatic malignancies and whether ADAM12 levels might serve as an independent predictor of disease status. Retrospective analyses of urine samples (n=130) from PDAC and pNET patients as well as age- and sex-matched controls were conducted. Urinary ADAM12 levels were determined using a monospecific ELISA system. In addition, ADAM12 protein expression in tumor and normal pancreatic tissues was analyzed via immunohistochemistry (IHC). Multivariable logistic regression analyses indicated that, when controlling for age and sex, urinary ADAM12 could serve as significant independent predictor for distinguishing PDAC (P&lt;0.001) and pNET (P&lt;0.008) patients from healthy controls. Kaplan-Meier analysis of estimated patient survival stratified by urinary ADAM12 levels indicated a significantly shorter patient survival time for PDAC patients with high ADAM12 levels (P=0.015) compared to patients with lower urinary ADAM12. In addition, IHC analysis indicated that ADAM12 protein expression was upregulated ∼4-fold in Grade I-III PDAC compared to normal pancreatic tissue. Taken together, our results suggest that the measurement of ADAM12 levels may have diagnostic value in detection and/or clinical monitoring of disease status in patients with pancreatic malignancies. [Supported by: The Advanced Medical Foundation]

Citation Format: Roopali Roy, David Zurakowski, Matthew Kulke, Marsha A. Moses. Urinary ADAM12 levels detect the presence of pancreatic cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 891. doi:10.1158/1538-7445.AM2014-891

Targeting the mTOR signaling pathway in neuroendocrine tumors

OPINION STATEMENT

Neuroendocrine tumors (NETs) are a heterogeneous group of malignancies characterized by variable but most often indolent biologic behavior. Well-differentiated NETs can be broadly classified as either carcinoid or pancreatic NET. Although they have similar characteristics on routine histologic evaluation, the 2 tumor subtypes have different biology and respond differently to treatment, with most therapeutic agents demonstrating higher response rates in pancreatic NETs compared with carcinoid. Until recently, systemic treatment options for patients with advanced NETs were limited. However, improvements in our understanding of signaling pathways involved in the pathogenesis, growth, and spread of NETs have translated into an expansion of treatment options. Aberrant signaling through the mechanistic pathway of rapamycin (mTOR) pathway has been implicated in neuroendocrine tumorigenesis. Additionally, altered expression of mTOR pathway components has been observed in NETs and has been associated with clinical outcomes. Targeting the mTOR pathway has emerged as an effective treatment strategy in the management of advanced NETs. In a randomized, placebo-controlled study of patients with advanced pancreatic NET, treatment with the mTOR inhibitor everolimus was associated with improved progression-free survival (PFS). Largely based upon these data, everolimus has been approved in the United States and Europe for the treatment of patients with advanced pancreatic NET. The activity of everolimus remains under investigation in patients with carcinoid tumors. In a randomized study of patients with advanced carcinoid tumors associated with carcinoid syndrome, the addition of everolimus to octreotide was associated with improved PFS compared with octreotide. However, the results did not meet the prespecified level of statistical significance based on central review of radiographic imaging. Results from a randomized study examining the efficacy of everolimus in patients with nonfunctional gastrointestinal and lung NETs are awaited. In addition, further investigation is needed to determine whether primary tumor site or other clinical and molecular factors can impact response to mTOR inhibition. Although everolimus can slow tumor progression, significant tumor reduction is rarely obtained. Targeting multiple signaling pathways is a treatment strategy that may provide better tumor control and overcome resistance mechanisms involved with targeting a single pathway. Results of ongoing and future studies will provide important information regarding the added benefit of combining mTOR inhibitors with other targeted agents, such as VEGF pathway inhibitors, and cytotoxic chemotherapy in the treatment of advanced NETs.

Urinary TIMP-1 and MMP-2 levels detect the presence of pancreatic malignancies

Background:

A majority of patients with pancreatic malignancies, including both pancreatic ductal adenocarcinoma (PDAC) and pancreatic neuroendocrine tumours (pNETs), present with advanced disease due to a lack of specific symptoms and current diagnostic limitations, making this disease extremely difficult to detect. Our goal was to determine whether urinary matrix metalloproteases (uMMPs) and/or their endogenous inhibitors, urinary tissue inhibitor of metalloproteases (uTIMPs), could be detected in the urine of patients with pancreatic malignancies and whether they may serve as independent predictors of disease status.

Methods:

Retrospective analyses of urine samples (n=139) from PDAC and pNET patients as well as age- and sex-matched controls were conducted. Urinary MMP-2 and uTIMP-1 levels were determined using ELISA and zymography. Biomarker expression in tumour and normal pancreatic tissues was analysed via immunohistochemistry (IHC).

Results:

Multivariable logistic regression analyses indicated that, when controlling for age and sex, uMMP-2 (P<0.0001) and uTIMP-1 (P<0.0001) but not uMMP-9, were significant independent predictors for distinguishing between PDAC patients and healthy controls. Our data also indicated that uMMP-2 was an independent predictor of the presence of pNET. In addition, uTIMP-1 levels could differentiate the two cancer groups, PDAC and pNET, respectively. Immunohistochemistry analysis confirmed that MMP-2 and TIMP-1 protein expression is significantly upregulated in PDAC tissue compared with the normal pancreas.

Conclusions:

Taken together, our results suggest that the detection of uMMP-2 and uTIMP-1 may have diagnostic value in the detection of pancreatic malignancies and that uTIMP-1 may be useful in distinguishing between pancreatic adenocarcinoma and neuroendocrine tumours.

Early adulthood body mass index, cumulative smoking, and esophageal adenocarcinoma survival

10

Background: Little is known about the individual and combined effect of early-adulthood obesity and cumulative smoking on the survival of esophageal adenocarcinoma (EAC) patients. Methods: We analyzed two independent cohorts of EAC patients: 235 patients from Toronto, Canada (TO, 2006-2011) and 329 patients from Boston, USA (BO,1999-2004). Associations between early adulthood body mass index (EA-BMI) and smoking with overall survival (OS) were assessed using Cox proportional hazard models, adjusted for stage, treatment, and other relevant covariates. Results: Median age (range) for TO dataset was 64(29-88)yrs; for BO dataset, 64(21-91)yrs. Males comprised 86% of TO and 89% of BO datasets. 90% of TO and 98% of BO patients were Caucasians. The Median (range) for packyears was 34 (0.2-118; TO) and 34 (0.2-212; BO). The Median (range) for EA-BMI was 24(15-44; TO) and 24(15-47; BO). Median BMI 1 yr prior to diagnosis was 25(16-43; TO) and 25(20-49; BO). 92% of TO and 88% of BO patients had ECOG 0 or 1. Disease stage distribution (early/locally-advanced/metastatic) was 11%/64%/25% (TO) and 30%/52%/18% (BO). For TO, the aHR for smoking was 1.03 (95%CI: 1.02-1.04; p=8E-08) per packyear, while for BO, smoking also independently conferred worse OS, with aHR of 1.007 (95%CI: 1.002-1.01; p=0.003) for each packyear increase. The aHRs for being underweight (EA-BMI<18.5), overweight (EA-BMI 25-30), and obese (EA-BMI>30) in early adulthood were 2.19 (95%CI: 1.0-4.6), 1.89 (95%CI:1.2-3.0), and 2.49 (95%CI:1.5-4.2), respectively for the TO dataset (global p=0.003 for EA-BMI). In BO, the corresponding values were 1.30 (95%CI: 0.8-2.2), 1.45 (95%CI: 1.0-2.5), and 2.39 (95%CI:1.5-3.8), respectively (global p=0.002). In contrast, BMI at one year prior to diagnosis had no association with OS in either study. Conclusions: Elevated BMI in early adulthood and heavy cumulative smoking history are independently associated with increased mortality risk in two North American EAC populations. These survival differences may reflect comorbidity differences, biological differences or both, and offer insight into how key modifiable behaviors in prevention can also affect cancer prognoses. AS, LC, DCC and GL contributed equally.

Somatic mutation of CDKN1B in small intestine neuroendocrine tumors

The diagnosed incidence of small intestine neuroendocrine tumors (SI-NETs) is increasing, and the underlying genomic mechanisms have not yet been defined. Using exome- and genome-sequence analysis of SI-NETs, we identified recurrent somatic mutations and deletions in CDKN1B, the cyclin-dependent kinase inhibitor gene, which encodes p27. We observed frameshift mutations of CDKN1B in 14 of 180 SI-NETs, and we detected hemizygous deletions encompassing CDKN1B in 7 out of 50 SI-NETs, nominating p27 as a tumor suppressor and implicating cell cycle dysregulation in the etiology of SI-NETs.

Free somatostatin receptor fraction predicts the antiproliferative effect of octreotide in a neuroendocrine tumor model: implications for dose optimization

Somatostatin receptors (SSTR) are highly expressed in well-differentiated neuroendocrine tumors (NET). Octreotide, an SSTR agonist, has been used to suppress the production of vasoactive hormones and relieve symptoms of hormone hypersecretion with functional NETs. In a clinical trial, an empiric dose of octreotide treatment prolonged time to tumor progression in patients with small bowel neuroendocrine (carcinoid) tumors, irrespective of symptom status. However, there has yet to be a dose optimization study across the patient population, and methods are currently lacking to optimize dosing of octreotide therapy on an individual basis. Multiple factors such as total tumor burden, receptor expression levels, and nontarget organ metabolism/excretion may contribute to a variation in SSTR octreotide occupancy with a given dose among different patients. In this study, we report the development of an imaging method to measure surface SSTR expression and occupancy level using the PET radiotracer (68)Ga-DOTATOC. In an animal model, SSTR occupancy by octreotide was assessed quantitatively with (68)Ga-DOTATOC PET, with the finding that increased occupancy resulted in decreased tumor proliferation rate. The results suggested that quantitative SSTR imaging during octreotide therapy has the potential to determine the fractional receptor occupancy in NETs, thereby allowing octreotide dosing to be optimized readily in individual patients. Clinical trials validating this approach are warranted.

Dosing patterns for octreotide LAR in neuroendocrine tumor (NET) patients: NCCN NET outcomes database

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Background: Among patients (pts) with neuroendocrine histology, 10 mg – 30 mg of octreotide-LAR administered intramuscularly every 4 weeks is FDA-approved for the long term treatment of severe diarrhea and flushing episodes associated with metastatic carcinoid tumors and pancreatic VIPomas. In clinical practice, higher doses and/or more frequent administration is often prescribed for pts who experience refractory symptoms (e.g., flushing and/or diarrhea) on the maximal labeled dose. Methods: National Comprehensive Cancer Network (NCCN) created a comprehensive longitudinal database to characterize pts treated for NETs. This database was queried to identify pts presenting to 7 NCCN institutions, from 2004 to 2010, with a confirmed carcinoid or pancreatic NET (pNET) diagnosis who received octreotide LAR. The primary aim of this analysis was to describe octreotide LAR dosing patterns when beyond label recommendations, clinical characteristics, reasons for dose increase, and maximal dose. Results: Among 1,886 pts in the database, 271 carcinoid and pNET pts received octreotide LAR. 40% of carcinoid pts (n=82) and 23% of pNET pts (n=15) received octreotide LAR above-label dosing, defined by dose and/or frequency greater than 30 mg every 4 weeks. The primary tumor sites among carcinoid pts receiving above label dosing were small bowel (n=40), colorectal (n=4), and unknown (n=34). Reasons for above label dosing among carcinoid pts included uncontrolled symptoms (n=53, 65%), tumor progression (n=21, 25%), high urine 5-HIAA (n=1, 1%) and unknown (n=7, 9%). The most common dose/frequency combinations for carcinoid pts were 40 mg every 4 weeks (32 pts, 39%), 40 mg every 3 weeks (15 pts, 18%), and 30 mg every 2 weeks (14 pts 17%). Among pNET pts, reasons for change included uncontrolled symptoms (n=5, 33%), tumor progression (n=9, 60%), and unknown (n=1, 7%). The most common maximal dose/frequency combinations among pNET pts were 40mg every 4 weeks (n=5, 33%), 30mg every 2 weeks (n=4, 27%), and 60 mg every 4 weeks (n=4, 27). Conclusions: Above label dosing of octreotide LAR is common in NCCN institutions. The primary indication is refractory carcinoid syndrome. Prospective studies are planned to validate this strategy.

Treatment of liver metastases in patients with neuroendocrine tumors: A National Comprehensive Cancer Network analysis

4143

Background: The choice of therapy in patients with hepatic metastases from neuroendocrine tumors is controversial. The purpose of this study was to describe the utilization of liver resection and other locoregional therapies in the management of NET hepatic metastases in NCCN centers. Methods: The National Comprehensive Cancer Network (NCCN) Neuroendocrine Tumor Database tracks longitudinal care for patients treated at seven specialty cancer centers in the U.S. from 2004 to 2010. Patient and tumor characteristics, as well as the use of liver-directed therapy (LDT) in patients with neuroendocrine liver metastases (NELM) were evaluated. Results: Among 907 patients presenting with metastatic disease, 606 patients presenting with newly diagnosed disease or previously diagnosed disease with first distant recurrence of NELM were evaluated. LDT was used during some component of the patient care in only 43% of patients with NELM, the remainder received only systemic or no therapy. LDT varied by extent of disease (p=0.002) with a higher proportion of patients with liver-only disease receiving LDT (45%) compared to those with liver and extrahepatic disease (26%). There was a significant difference in LDT by functional tumor status (Χ2=6.84, p=0.03) and primary site of disease (Χ2=14.95, p=0.001) where a higher proportion of patients with hormonally functional tumors received LDT when compared to non-functional tumors (48% vs 42%) as well as those with primary small bowel carcinoid vs pancreatic NET (56% vs 39%). Among those treated with LDT, 39% underwent surgical resection, 57% intra-arterial therapy (IAT), and 4% ablation alone. Major hepatectomy was performed in 21%, multiple resections in 13%, and resection combined with ablation in 24% of patients receiving surgical therapy. Among the 147 patients treated with IAT, 52% received standard chemoembolization, 23% bland embolization, and 18% yttrium-90 therapy. Conclusions: Even at specialty centers less than half of patients received LDT, among which one-fifth had a hepatic resection. Future studies on this cohort will measure outcomes based on type of LDT.

Baseline demographics of neuroendocrine tumor patients presenting to seven National Comprehensive Cancer Network (NCCN) institutions: Development of a multi-institutional outcomes database

e14551

Background: Diagnostic strategies, management paradigms, and clinical outcomes of patients with neuroendocrine tumors (NETs) are diverse and poorly characterized. The National Comprehensive Cancer Network (NCCN) created a comprehensive database to characterize patients treated for NETs at seven participating institutions. Preliminary results from the database are reported. Methods: Member IRB approval was obtained to identify patients at least 18 years of age presenting to each of seven NCCN institutions between 2004 and 2007 with pathologically confirmed newly or previously diagnosed NETs via hospital medical records. Eligible patients included those with carcinoid (any site); goblet cell or adenocarcinoid; composite carcinoid; poorly differentiated gastrointestinal small cell tumor; pancreatic NET; NET of unknown primary site; pheochromocytoma; and paraganglioma. Baseline demographic characteristics were summarized for this analysis. Results: Among the 2,798 patients identified with a NET diagnosis, patients most frequently presented with carcinoid tumor (53%), pancreatic NET (26%) and NET of unknown primary site (8%). Median age at diagnosis was 56 (SD=14). Fifty-three percent of patients were female. Most (86%) were Caucasian and 8% were African American. Thirty percent of patients were diagnosed with NET before presenting to the NCCN. Among these, the median time between initial NET diagnosis and presentation to the NCCN was 2 years (SD=6). Significant differences in provider specialty referral patterns were observed between institutions. The institutional point of entry for the majority of patients was medical oncology (institutional range: 17-93%) or surgery (institutional range: 3-62%). Conclusions: The baseline demographic characteristics of NET patients in this new database are consistent with those previously reported in population-based registries. The database will provide a valuable resource for further exploration of patterns of diagnosis, treatment, and consistency with established guidelines, as well as clinical outcomes in patients with this condition.

Description of initial treatment for newly diagnosed metastatic carcinoid (cNET) and pancreatic neuroendocrine (pNET) patients

e14542

Background: There is limited descriptive information regarding treatment (tx) patterns for NET from clinic practice data. The primary aim of this analysis was to describe initial tx among NET pts as a first step in understanding tx patterns for NET. Methods: The National Comprehensive Cancer Network (NCCN) Oncology Outcomes Database was queried to identify newly diagnosed pts presenting to 7 NCCN institutions with a confirmed metastatic cNET or pNET diagnosis in 2004 or 2005. Pts with a minimum of 5 years of follow up or confirmed death were included in the analysis. Pt demographics, clinical characteristics, initial tx, and 5-year survival were described. Results: Among 187 cNET pts, 52% were male, median age at diagnosis was 58, and 51% alive. Approximately 58% had a known primary tumor; 65% of which were in the small bowel. Most cNET pts (85%) presented with symptoms, 33% had carcinoid syndrome. Initial tx included surgical therapy in 43%, drug therapy in 41%, and other therapies in 16%. The majority (82%) had imaging prior to treatment, among which 79% had a CT scan and 35% had somatostatin receptor scintigraphy (SRS). The most frequent biomarker test was for CGA (performed in 64 pts, elevated in 53). Of 76 cNET pts receiving initial drug therapy, 82% were treated with a somatostatin analog (SA); others received chemotherapy or targeted therapy. Kaplan-Meier (K-M) curves indicated a 5-year survival of 62% and 56% among pts receiving surgery or drug therapy as initial tx, respectively. Among 104 pNET pts, 61% were male, median age at diagnosis was 54, and 41% alive. Approximately 82% presented with symptoms among which 25% were hormone related. Among the 84% of pts imaged prior to treatment, CT scan was most common (79%) and 38% had SRS. The most common initial tx among pNET pts was drug therapy (56%); 60% received a SA; 31% received chemotherapy. Only 25% underwent surgery as initial tx. K-M curves indicated a 5-year survival of 63% among surgical pts in contrast to 31% for pts whose initial tx was drug therapy. Conclusions: Initial tx among the majority of pts was either surgery or drug therapy. Among cNET and pNET pts receiving drug therapy, 82% (n=62) and 60% (n=35) respectively, received an SA.

Functional SNPs in vascular endothelial growth factor (VEGF-A) and overall survival (OS) in bevacizumab-treated patients with metastatic colorectal cancer (mCRC)

3594

Background: Functional SNPs in VEGF-A are prognostic for OS in several malignancies, but not described definitively in mCRC. In bevacizumab-treated patients with advanced breast cancer, VEGF -2578AA and -1154A were predictive of OS—the latter SNP reported in a recent mCRC series as well. We examined the association between five functional VEGF-A SNPs and OS in a large cohort of bevacizumab-treated patients with mCRC. Methods: 403 patients with mCRC treated from 2004-2010 were included in a retrospective analysis. DNA extraction, genotyping, and SNP evaluation were performed according to standard protocols. Survival was calculated from the time of Stage IV diagnosis until death. Data were censored as of 12/31/2010. Results: There were 279 deaths in this group of 403 patients (69%). Median age was 55.7 (24-86 y), and 54% of patients were male. Age, sex, race, tumor grade, chemotherapies, and curative surgery (metastatectomy to negative margins) were considered. Significant clinical predictors of OS in univariate Cox modeling were cetuximab treatment [HR=1.46; 95% CI 1.13-1.88; p=0.0014], irinotecan treatment [HR=2.10; 1.32-3.35; p<0.001], and curative surgery [HR=0.36; 0.25-0.75; p<0.001]. Significant negative interaction was found between both cetuximab and irinotecan and curative surgery, and in modeling that included this interaction, only surgery remained predictive. In multivariate analysis, no association was found between VEGF-A and OS (Table). Conclusions: There was no association between five functional VEGF-A SNPs and OS in this large bevacizumab-treated mCRC cohort. [Table: see text]

A multi-institutional phase II open-label study of AMG 479 in advanced carcinoid and pancreatic neuroendocrine tumors

4125

Background: The IGF pathway is thought play an important role in neuroendocrine tumor progression. We therefore investigated AMG 479, a human monocolonal antibody against IGF1-R, in patients with metastatic progressive carcinoid and pancreatic neuroendocrine tumors (NETS). Methods: This open-label phase II study enrolled patients (≥18 yrs) with metastatic low and intermediate-grade carcinoid and pancreatic NETs. Key inclusion criteria included evidence of progressive disease (by RECIST) within 12 months of enrollment, ECOG PS 0-2, and fasting blood sugar <160mg/dL. Prior treatments were allowed, and concurrent somatostatin analog therapy was permitted as long as patients remained on a stable dose. The primary endpoint was objective response rate. Secondary endpoints included overall survival (OS), progression-free survival (PFS), and safety. Results: 60 patients (30 carcinoid, 30 pancreatic NET) were treated with AMG 479 18mg/kg every 3 weeks and 54 patients were evaluable for response. There were no objective responders by RECIST. When best response to therapy was evaluated, 10/27 (37%) evaluable carcinoid patients and 8/26 (31%) evaluable pancreatic NET patients experienced 1-29% tumor shrinkage, while 17/27 (63%) of the carcinoid patients and 15/26 (58%) of the pancreatic NET patients appeared to experience continued tumor growth. Median PFS was 6.3 months (95% CI 4.2-12.6) for the entire cohort; 10.5 months for carcinoid patients and 4.2 months for pancreatic NET patients. The OS rate at 12 months was 70% (55%-81%) for the entire cohort. Median OS has not been reached. Treatment related grade 3/4 AEs were rare and consisted of hyperglycemia (4%), neutropenia (4%), thrombocytopenia (4%) and infusion reaction (1%). Conclusions: While well-tolerated, single-agent AMG 479 was not found to result in major tumor responses among patients with metastatic low-intermediate grade carcinoid or pancreatic NET. Subgroup analysis to identify characteristics of patients who may have benefited from therapy with AMG 479 is ongoing.

Relief of bowel-related symptoms with telotristat etiprate in octreotide refractory carcinoid syndrome: Preliminary results of a double-blind, placebo-controlled multicenter study

4085

Background: Diarrhea associated with carcinoid syndrome has been attributed to tumor production of serotonin. Telotristat etiprate, (LX1032, LX1606), is an oral inhibitor of peripheral serotonin synthesis. This study explored the safety, tolerability, and efficacy of telotristat etiprate in carcinoid patients with octreotide-refractory diarrhea. Methods: Carcinoid patients with ≥4 bowel movements (BMs)/day on octreotide were randomized 3:1 to receive telotristat etiprate or placebo as double-blind treatment. Patients enrolled in sequential, escalating dose cohorts of 150, 250, 350, or 500 mg tid, followed by a 500 mg tid expansion cohort. Patients were followed for toxicity, 24-hr urinary 5-HIAA (u5-HIAA), BM frequency, and self-reported bowel-related symptoms. Subjects were asked “In the past 7 days, have you had adequate relief of your carcinoid syndrome bowel complaints such as diarrhea, urgent need to have a bowel movement, abdominal pain or discomfort?” Responses (yes or no) were analyzed as categorical variables. Results: 16 patients enrolled in the 4 escalating dose cohorts and 7 in the expansion cohort; 18 on telotristat etiprate and 5 on placebo. Median age: 62 yrs; mean 6.3 BMs/day (range, 4-10). AEs included primarily mild-moderate diarrhea, nausea, and abdominal discomfort. In treated subjects, adequate relief was reported as: Week 1 - 6/18 (33.3%), Week 2 - 5/16 (31.3%), Week 3 - 5/15 (33.3%), and Week 4 - 6/13 (46.0%). No placebo subjects reported improvement at any timepoint. Biochemical response (≥50%reduction in u5-HIAA) and BM response (≥30% reduction in daily BMs for 2 weeks) were associated with reporting of adequate relief. For evaluable telotristat etiprate-treated patients, 9/16 (56%) experienced a biochemical response and 5/18 (28%) experienced a clinical (BM) response; no placebo subjects achieved either biochemical or clinical response. Conclusions: Treatment with telotristat etiprate was associated with decreases in u5-HIAA and BM frequency, and with self-reported relief of bowel related symptoms. Treatment in an extension phase with open-label telotristat etiprate is ongoing.

Prevalence of functional tumors in neuroendocrine carcinoma: An analysis from the NCCN NET database

4126

Background: Neuroendocrine tumors (NETs) are increasing in incidence and prevalence. Identification and treatment of specific clinical NET syndromes are established, yet there is uncertainty regarding the prevalence of NET with hormone-related symptoms versus nonfunctional tumors. Methods: The National Comprehensive Cancer Network (NCCN) created a comprehensive database to characterize patients (pts) treated for NETs. This database was queried to identify pts presenting to 7 NCCN institutions with a confirmed NET diagnosis: including carcinoid (cNET), pancreatic NET (pNET), NET not otherwise specified (NOS), and pheochromocytoma (PCC) between 2004 and 2010. The primary aim of this analysis was to describe demographic and clinical characteristics of NET pts by functional (fxn) status at diagnosis (dx). Results: Among 1244 NET pts, 26% (n=327) had an fxn tumor. Carcinoid syndrome (CS) occurred in 28% of cNET pts. The most common primary tumor sites among CS pts were small bowel (69%) and unknown (15%). Prevalence of hormonal syndrome (HS) among pNET pts was 22%, 24% among NOS pts and 37% among PCC pts. The majority of CS pts (74%), pNET HS pts (67%), and NOS HS pts (91%) had distant disease at dx, in contrast to 31% of PCC HS patients. Among CS pts with a known histologic grade, 91% were well differentiated (G1). Similarly, 86% of pNET HS and 67% of NOS HS pts with a known histologic grade had G1 NETs. The most common symptoms at dx among pts with CS included abdominal cramping (53%), change in bowel habits (48%), and flushing (40%). Among those tested, 85% of CS pts had a positive 5-HIAA test at dx. Among pNET HS pts, the most common symptoms present at dx were abdominal cramping (39%) and change in bowel habits (46%). The most common symptoms present at dx among NOS HS pts were abdominal cramping (35%), change in bowel habits (47%) and flushing (38%). Conclusions: Prevalence of CS in this NCCN database (28%) was slightly higher than the 10% previously reported in the literature. In contrast, the prevalence of HS among pNET pts (22%) was lower than previously reported. Approximately one quarter of cNET pts without metastatic disease had CS, warranting further analysis as CS most often occurs in the presence of liver metastasis.

Pheochromocytoma and paraganglioma: imaging characteristics

The accurate diagnosis of adult pheochromocytoma and paraganglioma necessitates a multidisciplinary approach that includes clinical history, biochemical testing, and multimodality imaging such as computed tomography, magnetic resonance imaging, and nuclear medicine studies. This review illustrates the different imaging characteristics of primary adult pheochromocytomas as well as both sympathetic and parasympathetic paragangliomas. The review also describes known genetic associations and shows common metastatic patterns. Knowledge of the diverse appearance of pheochromocytomas and paragangliomas can result in early initial diagnosis or detection of disease recurrence thereby affecting patient management and prognosis.

Relief of bowel-related symptoms with telotristat etiprate in octreotide refractory carcinoid syndrome: Preliminary results of a placebo-controlled, multicenter study

312

Background: Diarrhea associated with carcinoid syndrome (CS) has been attributed to tumor production of serotonin. Telotristat etiprate, (LX1032, LX1606), is an oral inhibitor of peripheral serotonin synthesis. This study explored the safety, tolerability, and efficacy of telotristat etiprate in carcinoid patients with octreotide-refractory diarrhea.

Methods: Carcinoid patients with >4 bowel movements (BM)/day on octreotide were randomized 3:1 to receive telotristat etiprate or placebo. Patients enrolled in sequential, escalating dose cohorts of 150, 250, 350, or 500 mg tid, followed by a 500 mg tid expansion cohort. Patients were followed for toxicity, 24-hr urinary 5-HIAA (u5-HIAA) secretion, BM frequency, and self-reported relief of bowel-related symptoms. Subjects were asked “In the past 7 days, have you had adequate relief of your carcinoid syndrome bowel complaints such as diarrhea, urgent need to have a bowel movement, abdominal pain or discomfort?” Responses (yes or no) were analyzed as categorical variables.

Results: 16 patients enrolled in the 4 escalating dose cohorts and 7 in the expansion cohort; 18 on telotristat etiprate and 5 on placebo. Median age was 62 yrs with a mean 6.2 BMs/day (range 4-10). AEs included primarily mild-moderate diarrhea, nausea, and abdominal discomfort. In treated subjects, adequate relief was reported as follows: Week 1 – 6/18 (33.3%), Week 2 – 5/16 (31.3%), Week 3 - 5/15 (33.3%), and Week 4 – 6/12 (50.0%). No placebo subjects reported improvement at any timepoint. Biochemical response (>50%reduction in u5-HIAA) and BM response (>30% reduction in daily BM for 2 weeks) were associated with reporting of adequate relief. For evaluable telotristat etiprate-treated patients, 9/16 (56%) experienced a biochemical response and 5/18 (28%) experienced a clinical (BM) response; no placebo subjects achieved either biochemical or clinical response.

Conclusions: Treatment with telotristat etiprate was associated with decreases in u5-HIAA and BM frequency, and with self-reported relief of bowel related symptoms. Treatment in an extension phase with open-label telotristat etiprate is ongoing.

Baseline demographics of patients with neuroendocrine tumors presenting to seven National Comprehensive Cancer Network (NCCN) institutions: Development of a multi-institutional outcomes database

187

Background: Diagnostic strategies, management paradigms, and clinical outcomes of patients with neuroendocrine tumors (NETs) are diverse and poorly characterized. The National Comprehensive Cancer Network (NCCN) created a comprehensive longitudinal database to characterize patients treated for NETs at seven participating institutions. Preliminary results from the database are reported.

Methods: Member IRB approval was obtained to identify patients at least 18 years of age presenting to each of seven NCCN institutions between 2004 and 2007 with pathologically confirmed newly or previously diagnosed NETs via hospital medical records. Eligible patients included those with carcinoid (any site); goblet cell or adenocarcinoid; composite carcinoid; poorly differentiated gastrointestinal small cell tumor; pancreatic NET; NET of unknown primary site; pheochromocytoma; and paraganglioma. Baseline demographic characteristics were summarized for this analysis.

Results: Among the 2,542 patients identified with a NET diagnosis, patients most frequently presented with carcinoid tumor (51%), pancreatic NET (27%) and NET of unknown primary site (8%). Median age at diagnosis was 55 (SD=13) and median age at first presentation to the NCCN was 57 (SD=13). Fifty-three percent of patients were female. Most (88%) were Caucasian and 8% were African American. Forty percent of patients were diagnosed with NET before presenting to the NCCN. Among these, the median time between initial NET diagnosis and presentation to the NCCN was 2 years (SD=6). Significant differences in provider specialty referral patterns were observed between institutions.

Conclusions: The baseline demographic characteristics of NET patients in this new database are consistent with those previously reported in population-based registries. The NCCN database will provide a valuable resource for further exploration of patterns of diagnosis, treatment, consistency with established guidelines, as well as clinical outcomes in patients with this condition. Existing differences among institutions in referral patterns will be further explored.