NETest: serial liquid biopsies in gastroenteropancreatic NET surveillance

Objective: Up to now, serial NETest measurements in individuals assessing the disease course of gastroenteropancreatic neuroendocrine tumors (GEPNETs) at long-term follow-up and treatment response were not studied. Design: The study was a longitudinal validation study of serial NETest measurements – a blood-based gene expression signature – in 132 patients with GEPNETs on therapy or watch-and-wait strategy. Methods: Serial samples were collected during 46 (range: 6–71) months of follow-up. NETest scores were compared with Response Evaluation Criteria in Solid Tumors version 1.1-defined treatment response (e.g. no evidence of disease (NED), stable disease (SD) or progressive disease (PD)). Results: Consecutive NETest scores fluctuated substantially (range: 0–100) over time in individuals with SD (n = 28) and NED (n = 30). Follow-up samples were significantly higher in SD (samples 3–5) and NED subgroups (samples 2–5) compared with baseline results, without changes in imaging. In 82% of untreated patients with PD, consecutive NETest scores consistently remained high. In patients undergoing systemic treatment, the median pre-treatment NETest score in treatment-responders was 76.5 (n = 22) vs 33 (n = 12) in non-responders (P = 0.001). Patients with low pre-treatment scores had 21 months reduced progression-free survival (10 vs 31 months; P = 0.01). The accuracy of the NETest for treatment response prediction was 0.73 (P = 0.009). Conclusion: In patients not undergoing treatment, consecutive low NETest scores are associated with indolent behavior. Patients who develop PD exhibit elevated scores. Elevated results have important predictive value for treatment responsiveness and could be used for individualizing decisions on systemic therapy. The clinical value of follow-up NETest scores for patients who choose to watch and wait requires further study

Patient-Derived Organoid Models of Human Neuroendocrine Carcinoma

Gastroenteropancreatic neuroendocrine carcinoma (GEP-NEC) is a poorly understood disease with limited treatment options. A better understanding of this disease would greatly benefit from the availability of representative preclinical models. Here, we present the potential of tumor organoids, three-dimensional cultures of tumor cells, to model GEP-NEC. We established three GEP-NEC organoid lines, originating from the stomach and colon, and characterized them using DNA sequencing and immunohistochemistry. Organoids largely resembled the original tumor in expression of synaptophysin, chromogranin and Ki-67. Models derived from tumors containing both neuroendocrine and non-neuroendocrine components were at risk of overgrowth by non-neuroendocrine tumor cells. Organoids were derived from patients treated with cisplatin and everolimus and for the three patients studied, organoid chemosensitivity paralleled clinical response. We demonstrate the feasibility of establishing NEC organoid lines and their potential applications. Organoid culture has the potential to greatly extend the repertoire of preclinical models for GEP-NEC, supporting drug development for this difficult-to-treat tumor type

Advances in Radionuclide Therapies for Patients with Neuro-endocrine Tumors

Purpose of Review: To provide insights into the role of peptide receptor radionuclide therapy (PRRT) in patients with advanced neuroendocrine tumors (NET) and an overview of possible strategies to combine PRRT with locoregional and systemic anticancer treatments. Recent Findings: Research on combining PRRT with other treatments encompasses a wide variety or treatments, both local (transarterial radioembolization) and systemic therapies, chemotherapy (i.e., capecitabine and temozolomide), targeted therapies (i.e., olaparib, everolimus, and sunitinib), and immunotherapies (e.g., nivolumab and pembrolizumab). Furthermore, PRRT shows promising first results as a treatment prior to surgery. Summary: There is great demand to enhance the efficacy of PRRT through combination with other anticancer treatments. While research in this area is currently limited, the field is rapidly evolving with numerous ongoing clinical trials aiming to address this need and explore novel therapeutic combinations

Survival in patients with neuroendocrine tumours of the small intestine: Nomogram validation and predictors of survival

Neuroendocrine tumours of the small intestine (SI‐NETs) are rare and heterogeneous. There is an unmet need for prognostication of disease course and to aid treatment strategies. A previously developed nomogram based on clinical and tumour characteristics aims to predict disease‐specific survival (DSS) in patients with a SI‐NET. We aimed to validate the nomogram and identify predictors of survival. Four hundred patients with a grade 1 or 2 SI‐NET were included, between January 2000 and June 2016. Predicted 5‐ and 10‐year survival was compared to actual DSS. Multivariable analysis identified predictors for actual DSS. We found that in low‐, medium-and high‐risk groups 5‐year nomogram DSS vs. actual DSS was 0.86 vs. 0.82 (p 6x ULN and elevated liver tests were identified as independent predictors for a worse DSS. This shows that the nomogram was able to differentiate, but underestimated DSS for patients with a SI‐NET. Improvement of prognostication incorporating new emerging biomarkers is necessary to adequately estimate survival

Nephrotoxicity as a Dose-Limiting Factor in a High-Dose Cisplatin-Based Chemoradiotherapy Regimen for Head and Neck Carcinomas

Purpose: Loco-regional control and organ preservation are significantly improved with concomitant cisplatin/radiotherapy and are compromised with less than 5% grade 3 nephrotoxicity (creatinine clearance 15–29 mL/min). However, although clinically important, in none of the randomized trials is grade 2 nephrotoxicity (defined as creatinine clearance 59–30 mL/min) mentioned. In this study, we assessed nephrotoxicity in daily practice among patients treated with high-dose cisplatin (100 mg/m2 on days 1, 22, and 43), concurrently with chemoradiotherapy (CCRT) and the impact on treatment modifications. Methods: 208 patients with advanced-stage malignancies of the head and neck region were evaluated. All patients were treated with high-dose cisplatin CCRT. The main outcome parameters were nephrotoxicity (defined as creatinine clearance grade 2 or more) and cumulative doses of cisplatin and radiation. Results: 133 patients (64%) completed all pre-planned courses of cisplatin. Nephrotoxicity was the main reason to discontinue the chemotherapy. Grade 3 nephrotoxicity was seen in 16 patients (8%) while grade 2 nephrotoxicity was seen in 53 patients (25%). Thirty six patients (17%) could not complete the pre-planned chemotherapy due to nephrotoxicity. Conclusions: In head and neck cancer patients, nephrotoxicity grade 2 is under-reported but is the major factor for discontinuing cisplatin during CCRT

Inflammatory markers and long term hematotoxicity of holmium-166-radioembolization in liver-dominant metastatic neuroendocrine tumors after initial peptide receptor radionuclide therapy

Purpose: In patients with neuroendocrine tumor liver metastases, additional tumor reduction can be achieved by sequential treatment with [166Ho]-radioembolization after peptide receptor radionuclide therapy (PRRT). The aim of this study was to analyze hematotoxicity profiles, (i.e. lymphocyte and neutrophile toxicity) and the prognostic value of neutrophil-to-lymphocyte ratio (NLR) and thrombocyte-to-lymphocyte ratio (TLR). Methods: All patients included in the prospective HEPAR PLuS study were included in this study. Blood testing was performed at baseline (before radioembolization) and at regular intervals during 1-year follow-up. Radiological response was assessed at 3, 6, 9, and 12 months according to RECIST 1.1. Logistic regression was used to analyze the prognostic value of NLR and TLR on response. Results: Thirty-one patients were included in the toxicity analysis; thirty were included in the response analysis. Three weeks after radioembolization, a significant decrease in lymphocyte count (mean change − 0.26 × 109/L) was observed. Ten patients (32.2%) experienced grade 3–4 lymphocyte toxicity. This normalized at 6 weeks and 3 months after treatment, while after 6 months a significant increase in lymphocyte count was observed. An increase in NLR and TLR at 3 weeks, compared to baseline, significantly predicted response at 3 months (AUC = 0.841 and AUC = 0.839, respectively) and at 6 months (AUC = 0.779 and AUC = 0.765). No significant relation with survival was found. Conclusions: Toxicity after sequential treatment with PRRT and [166Ho]-radioembolization is limited and temporary, while significant additional benefit can be expected. Change in NLR and TLR at 3-weeks follow-up may be valuable early predictors of response. Trial registration ClinicalTrials.gov, NCT02067988. Registered 20 February 2014, https://clinicaltrials.gov/ct2/show/record/NCT02067988

A serum and platelet-rich plasma serotonin assay using liquid chromatography tandem mass spectrometry for monitoring of neuroendocrine tumor patients

Background Serotonin is used for the diagnosis and follow-up of neuroendocrine tumors (NET). We describe the analytical and clinical validation of a liquid chromatography tandem mass spectrometry (LC-MS/MS) based serotonin assay for serum and platelet-rich plasma (PRP). Methods An LC-MS/MS based method for serum and PRP serotonin was validated by determination of assay imprecision, carry-over, linearity, interference, recovery, sample stability and a matrix/method comparison of serum and PRP serotonin was made with whole blood serotonin. Furthermore, upper limits of normal were determined and serotonin concentrations of healthy individuals, 14 NET patients without evidence of disease and 51 NET patients with evidence of disease were compared. Results For serum and PRP fractions, total assay imprecision was <5%. All correlation coefficients were 0.98 and the serum and platelet-rich serotonin upper limit of normal were 5.5nmol/109 platelet and 5.1nmol/109 platelet, respectively. NET patients with confirmed evidence of disease had significantly higher serum and PRP serotonin levels when compared to NET patients without evidence of disease and healthy volunteers. Conclusions LC-MS/MS based serum and PRP serotonin assays were developed with suitable analytical characteristics. Furthermore, serum and PRP serotonin was found to be useful for monitoring NET patients

Survival in Patients with Neuroendocrine Tumours of the Small Intestine: Nomogram Validation and Predictors of Survival

Neuroendocrine tumours of the small intestine (SI-NETs) are rare and heterogeneous. There is an unmet need for prognostication of disease course and to aid treatment strategies. A previously developed nomogram based on clinical and tumour characteristics aims to predict disease-specific survival (DSS) in patients with a SI-NET. We aimed to validate the nomogram and identify predictors of survival. Four hundred patients with a grade 1 or 2 SI-NET were included, between January 2000 and June 2016. Predicted 5- and 10-year survival was compared to actual DSS. Multivariable analysis identified predictors for actual DSS. We found that in low-, medium- and high-risk groups 5-year nomogram DSS vs. actual DSS was 0.86 vs. 0.82 (p &lt; 0.001), 0.52 vs. 0.71 (p &lt; 0.001) and 0.26 vs. 0.53 (p &lt; 0.001), respectively. Ten-year nomogram DSS vs. actual DSS was 0.68 vs. 0.69 (p &lt; 0.001), 0.40 vs. 0.50 (p &lt; 0.001) and 0.20 vs. 0.35 (p &lt; 0.001), respectively. Age, WHO-performance score of 2, Ki-67 index &ge;10, unknown primary tumour, CgA &gt; 6x ULN and elevated liver tests were identified as independent predictors for a worse DSS. This shows that the nomogram was able to differentiate, but underestimated DSS for patients with a SI-NET. Improvement of prognostication incorporating new emerging biomarkers is necessary to adequately estimate survival