Sensitivity and Specificity of the NETest: A Validation Study.

BACKGROUND: Secretory tumor markers traditionally measured in patients with neuroendocrine tumors (NET) are lacking sensitivity and specificity, and consequently they are of limited clinical utility. The NETest, a novel blood multigene RNA transcript assay, has been found to be highly sensitive and specific. We sought to validate the sensitivity of the NETest in a population of metastatic well-differentiated NETs of gastroenteropancreatic and lung origin and to evaluate NETest specificity in a mixed population of metastatic non-NET gastrointestinal (GI) malignancies and healthy individuals. DESIGN AND METHODS: Forty-nine patients with metastatic NETs, 21 patients with other metastatic GI cancers, and 26 healthy individuals were enrolled in the study. Samples were sent in a blinded fashion to a central laboratory, and an NETest value of 0-13% was considered normal. RESULTS: Using 13% as the upper limit of normal, the sensitivity of the NETest was 98% (95% CI 89-100%). The overall specificity was 66% (95% CI 51-79%), with 16 false-positive results. Specificity was 81% (95% CI 62-92%) among 26 healthy individuals and 48% (95% CI 26-70%) among patients with other GI malignancies. Using an updated normal range of 0-20%, sensitivity was unchanged, but specificity improved to 100% among healthy participants and to 67% among patients with other cancers. CONCLUSIONS: The sensitivity of the NETest is exceptionally high (>95%) in a population of metastatic, well-differentiated NETs. Specificity within a healthy population of patients is exceptionally high when using a normal range of 0-20% but relatively low when evaluating patients with other GI malignancies.

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

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

Neoadjuvant GTX chemotherapy and IMRT-based chemoradiation for borderline resectable pancreatic cancer.

BACKGROUND AND OBJECTIVES: To improve the likelihood of achieving a margin-free resection, neoadjuvant induction chemotherapy with GTX (gemcitabine, docetaxel, and capecitabine) followed by 5-FU-IMRT was administered to patients with borderline resectable pancreatic cancer. The utility of computed tomography (CT), endoscopic ultrasound (EUS), positron emission tomography (PET), and CA 19-9 during diagnostic workup and assessment of response was also examined. METHODS: Seventeen patients with borderline resectable pancreatic cancer received a median of three cycles of neoadjuvant GTX induction chemotherapy followed by 5-FU-IMRT with dose painting. CA 19-9, CT mass size, and PET SUV were examined before and after neoadjuvant treatment. RESULTS: Diagnostic EUS and CT scans displayed similar mean mass sizes and extent of vascular involvement. Eight of the 17 patients achieved an R0 resection. Median CA 19-9 levels, CT mass size, and PET SUV all significantly decreased after neoadjuvant therapy. The median progression-free survival and overall survival were 10.48 and 15.64 months, respectively. Six patients are still alive. CONCLUSIONS: Neoadjuvant GTX induction chemotherapy followed by 5-FU-IMRT shows promise in improving the likelihood of resectability with negative margins in borderline resectable pancreatic cancer. CT and EUS play complimentary roles during diagnostic workup. CT scans, CA 19-9, and PET scans are useful in judging response to neoadjuvant therapy.

Optimizing the Management of Carcinoid Syndrome to Reduce the Impact of Diarrhea.

Diarrhea is often a presenting symptom in patients with neuroendocrine tumors (NETs). Frequently diagnosed in advanced stages, carcinoid syndrome diarrhea negatively impacts patients' well-being and quality of life. This article will review the diagnostic work-up for neuroendocrine tumors and etiology and management of NET-related carcinoid syndrome diarrhea and provide guidance for advanced practitioners, including nurse practitioners, physician assistants, pharmacists, and dieticians, focusing on their role in patient and caregiver education regarding disease, symptom monitoring and management, development of patient-specific treatment, and survivorship plans.

A phase II study of RO4929097 in metastatic colorectal cancer.

BACKGROUND: The Notch signalling pathway is activated in a variety of malignancies and has been implicated in colorectal cancer progression. One of the first steps in the Notch pathway activation is mediated by γ-secretase, a proteolytic enzyme which produces an activated intracellular Notch (ICN). RO4929097 is a selective inhibitor of γ-secretase. We tested the activity of RO4929097 in patients with metastatic, refractory colorectal cancer. PATIENTS AND METHODS: Patients with metastatic colorectal cancer who had received at least two prior lines of systemic chemotherapy were enrolled on the study. Patients were treated with RO4929097 at its recommended phase II dose of 20mg daily, 3 days on and 4 days off continuously. Cycle length was 28 days. Imaging was performed every two cycles. Archival tissue specimens were stained immunohistochemically for components of the notch pathway: Notch1, ICN and the downstream target HES1. RESULTS: Thirty-seven patients were enrolled of whom 33 were evaluable for toxicity and response. Immunohistochemical analysis of archival tissues demonstrated positive staining for the notch receptor as well as intracellular notch and the downstream gene HES1 in the majority of patients. Nevertheless, no objective radiographic responses were observed in this group and only six patients had stable disease as their best response. Median PFS was 1.8 months and median overall survival (OS) was 6.0 months. CONCLUSION: In this study of RO4929097 in patients with refractory metastatic colorectal cancer, no radiographic responses were seen and time to progression was short, which suggests that RO4929097 at the study dose and schedule has minimal single agent activity in this malignancy.