A Phase II Trial of Ziv-Aflibercept in Patients With Advanced Pancreatic Neuroendocrine Tumors

OBJECTIVES

Therapies for patients with advanced well-differentiated pancreatic neuroendocrine tumors (pNETs) are insufficient, with patients succumbing to disease despite recent treatment advances. Ziv-aflibercept is a fusion protein of portions of the vascular endothelial growth factor (VEGF) receptors 1 and 2, fused to the Fc portion of immunoglobulin G1, forming a VEGF trap. Perfusion computed tomography (CT) has previously defined hyperperfused neuroendocrine tumors, potentially predicting antiangiogenic benefit.

METHODS

We performed a single-arm open-label study, using the Simon optimal 2-stage design, of 6 mg/kg ziv-aflibercept in patients with advanced pNETs. The primary end point was objective radiographic response, with a hierarchically tested co-primary end point of response prediction by baseline hyperperfusion, defined as blood volume greater than 5.25 mL/100 g and permeability surface area product greater than 25 mL/min per 100 g.

RESULTS

Between July 3, 2014, and September 28, 2016, 21 patients were treated. Two patients (9.5%; 95% confidence interval, 1.1%-30.4%) demonstrated objective response, satisfying criteria to open the second stage, but the study was terminated for accrual. Perfusion CT could not be confirmed to predict radiographic response. Toxicities include 1 grade 5 gastrointestinal hemorrhage and 5 incidents of proteinuria requiring treatment discontinuation.

CONCLUSIONS

Responses with ziv-aflibercept were consistent with other VEGF inhibitors in pNET, but perfusion CT could not be confirmed to predict outcome.

Field-Echo Pulse Sequences Used under Suspended Respiration for Detection of Liver Metastases

To obtain a fast MRI sequence for detection of liver metastases under suspended respiration, two healthy volunteers were examined with the field echo sequence FLASH, using a large number of repetition times, echo times, flip angles and matrix sizes. The spleen was used to simulate liver metastases and contrast-to-noise ratios between liver and spleen were calculated and the sequence with the highest ratio was considered optimal. The different FLASH sequences were also compared with spin echo sequences using short repetition and echo times. A FLASH sequence with a repetition time of 140 ms, an echo time of 14 ms, a flip angle of 80 to 100 degrees and a matrix size of 128×256 was considered the most suitable for detecting liver metastases. This sequence, together with other FLASH and spin echo sequences, were used for examination of five patients with liver metastases from endocrine gastrointestinal tumours.

Evaluation of Intrahepatic Tumour Extent and Prediction of Resection Size in Liver Tumours by Computed Tomography, Ultrasonography and Angiography

Preoperative radiologic examinations were reviewed in 110 patients planned for liver resection. Forty-five patients had a CT examination within a month before the operation; 22 of these also had ultrasonography (US) and 38 had angiography. In a numeric analysis of lesions, true positive findings were observed at CT and US in 69 per cent and 61 per cent, respectively. Angiography, mainly performed to show the vascular anatomy and patency of the portal vein and not to optimize tumour detection, showed 55 per cent of the lesions. Attempts were made to predict resection size with CT by estimating intrahepatic tumour extent. CT showed correct tumour extent in 73 per cent but was inaccurate in 12 of 45 examinations. In 5 of these, tumour growth across the main and sagittal fissures was misinterpreted, with both under- and overestimations. Improvements of current imaging methods are needed to make the radiologic assessment prior to liver surgery more reliable.

CT, MR Imaging and Angiography in Pancreatic Apudomas

Findings at CT, MR imaging and angiography in 29 patients with pancreatic apudomas are presented. CT and angiography were performed in all the patients, MR imaging in 10. Twenty-five patients underwent laparotomy. The ability of the different imaging methods to localize the primary tumor and detect hepatic metastases was compared. CT and MR imaging depicted the primary tumor in 79% and 88% of the cases respectively, angiography in 72%. Enhancement patterns at CT and signal intensity variations at MR imaging were unspecific parameters regarding different types of tumors. CT and MR imaging were considerably more accurate than angiography in evaluating local tumor resectability. Angiography revealed more numerous small hepatic metastases (<0.5 cm) than CT or MR imaging, but missed metastases in the left lobe in 5 patients. MR imaging seems promising in localizing and characterizing pancreatic apudomas, but further evaluation is needed before any conclusion can be drawn. At present dynamic incremental CT seems mandatory in the evaluation of pancreatic apudomas. Angiography is of value for preoperative and preembolization vascular mapping, and in localizing small pancreatic apudomas not shown at CT or MR imaging. Faster dynamic thin slice CT scanning and fast-sequence MR imaging may increase the sensitivity of detecting small primary pancreatic apudomas.

Neuroendocrine gastro-enteropancreatic tumors - from eminence based to evidence-based medicine - A Scandinavian view

Neuroendocrine tumors (NETs) comprise a heterogenous group of neoplasms with variable clinical expression and progression. The primary tumors most frequently occur in the lungs, intestine and the pancreas. The NET incidence is approximately 6.1/100,000 per year with a prevalence higher than 35/100,000 per year. A NET may be functioning with symptoms related to hormone overproduction or non-functioning, not presenting any hormone-related symptoms. From the early 1980s and onwards, Uppsala University Hospital has contributed significantly to diagnosis, just to mention immunohistochemistry, radio-immunoassays for hormones and peptides and molecular imaging. On the therapeutic side, treatments with cytotoxics as well as biologicals such as, somatostatin analogs and interferons have been evaluated. We have furthermore been involved in important phase III trials for registration of so called, new targeted agents such as, RADIANT-3 and RADIANT-2. Our group were also the first to localize the gene for MEN I on chromosome 11 locus q13. Most recent developments have been the establishments of new biomarkers such as, olfactory receptor E51E1 as well as micro-RNAs in carcinoid tumors of the intestine and lung. A new oncolytic virus, Ad-Vince, for treatment of most NETs has been developed and is ready for the clinic. Furthermore, we have been involved in establishing Nordic and international collaborations. Today, NETs is an area with rapid development and recognized by international organizations at conferences, with large attendance. The Nordic countries continue to be significant contributors to the field.

Diagnostic, surgical and medical aspect of the midgut carcinoids

This review covers the incidence, prognosis, diagnosis and treatment of midgut carcinoids with emphasis on the surgical and peri-operative aspects. Midgut carcinoids are rare neuro-endocrine tumours which become manifest once they have metastasized to the liver. Treatment of metastatic disease may include radical resection but is usually palliative. The tumour grows relatively slow. Besides the biochemical effects resulting in the carcinoid syndrome, patients may suffer from mechanical mass effects of the tumour. Medical treatment can alleviate the biochemical effects of the tumour, but has a limited effect on tumour growth. The introduction of octreotide was a milestone in palliation of these symptoms and has led to more aggressive treatment protocols. Treatment aimed at cytoreduction of hepatic metastasis and diminished secretion of bioactive amines may achieve good palliation. Cytoreduction may be performed by means of surgery, hepatic arterial ligation, (chemo)embolization, cryosurgery, radio-frequency ablation, internal radiation or even liver transplantation. The role of these options will be discussed in this review.

Carcinoid disease: review of the literature

Carcinoid syndrome is the product of a rare but fascinating malignant neoplasm. Carcinoid syndrome was described more than 100 years ago, and recent advances in diagnostic localization, elucidation of the mechanisms of oncogenesis, treatment options, and, consequently, patient prognosis have been made. Current modalities of treatment, possible therapeutic implications of new avenues of research, and current literature on the chemotherapeutic combinations used are reviewed.

Detection of hepatocellular carcinoma by intraarterially enhanced ultrasonography with CO2 microbubbles. Comparison with DSA, dynamic CT, and Lipiodol CT

PURPOSE

To evaluate the diagnostic value of contrast-enhanced US with CO2 microbubbles (EU) for HCCs. Detectability was compared with DSA, dynamic CT, and Lipiodol CT.

MATERIAL AND METHODS

Forty-seven histologically proven HCCs detected with US were evaluated with EU, DSA, and dynamic CT. In 23 patients (35 lesions), Lipiodol CT was also performed. The size of the tumors ranged from 8 to 71 mm (average 28.1 mm); 24 lesions were smaller than 20 mm and 23 lesions were larger than 20 mm.

RESULTS

Overall detection was possible in 40 of 47 lesions (85%) by EU, in 32 of 47 (68%) by DSA, in 33 of 47 (74%) by dynamic CT, and in 27 of 35 (77%) by Lipiodol CT. In tumors smaller than 20 mm, detection was possible in 21 of 24 lesions (88%) by EU, 14 of 24 (58%) by DSA, 14 of 24 (58%) by dynamic CT, and 11 of 17 (65%) by Lipiodol CT.

CONCLUSION

EU has significant diagnostic value for detection of HCCs, particularly tumors smaller than 20 mm.

Prospective comparative study of ability of MR imaging and other imaging modalities to localize tumors in patients with Zollinger-Ellison syndrome

The role of magnetic resonance (MR) imaging in patients with pancreatic endocrine tumors such as Zollinger-Ellison syndrome (ZES) is controversial. In the present study we have examined the ability of current MR imaging compared with other imaging modalities, to localize gastrinomas in 43 patients with ZES. All results were subsequently assessed at exploratory laparotomy (N = 34) or by liver biopsy (N = 9). For the 18 patients with metastatic gastrinoma in the liver, MR imaging had a sensitivity of 83%, ultrasound 50%, CT 56%, and angiography 61%. The combination of MR imaging, ultrasound, and CT were the same as MR imaging alone. For MR imaging, both T1 and STIR sequences had equal sensitivity, although tumors were more easily seen with STIR sequences. Specificity of MR imaging was slightly lower (88%) than the other modalities (96-100%) because MR imaging incorrectly identified small hemangiomas as possible tumors in four patients. MR imaging was better than CT in identifying metastatic lesions in the liver. For the localization of primary gastrinoma, assessed in 32 patients, MR imaging had a sensitivity of 25%, ultrasound 19%, CT 28%, all three together 38%, and angiography 59%. Localization of metastatic gastrinoma in the liver or primary gastrinomas in 16 patients was assessed before and after gadolinium-DTPA (0.1 mmol/kg). The sensitivity and specificity of MR imaging was unchanged but bolus injection and rapid MR acquisition techniques were not used. These results indicate that recent advances in MR imaging have greatly improved its sensitivity for the detection and assessment of the extent of metastatic gastrinoma. MR imaging is now the imaging study of choice to assess metastatic pancreatic endocrine tumors in the liver. In contrast, the detection of primary tumors by MR imaging has not improved; therefore, angiography remains the study of choice.

Surgical treatment of mid-gut carcinoid tumors

Coincident with medical antitumor treatment of 138 patients suffering from mid-gut carcinoid tumors, 51 patients were subjected to surgery with the principal aims of removing primary tumors and debulking mesenteric or liver metastases. Sixteen patients had previously been operated with intestinal resection or, when the tumors had been considered inexcisable, with intestinal bypass or laparotomy alone. Apart from exhibiting symptoms related to the carcinoid syndrome, the majority (approximately 60%) of the 51 patients had generally intermittent, subileus-like abdominal pain and weight loss. In 18 patients, these symptoms were pronounced and associated with intestinal obstruction or severe malnutrition. Computed tomography and arteriography efficiently demonstrated mesenteric and liver metastases. At laparotomy, the primary intestinal tumors were small, mainly less than 1 cm in diameter, and they were multiple in 39% of the patients. Mesenteric metastases measuring up to 12 cm in diameter were present in 86% of the patients. These metastases were frequently associated with a pronounced mesenteric and retroperitoneal fibrosis causing fixation, angulation, and obstruction of the bowel as well as incipient intestinal gangrene in 8 patients. In all but 6 patients, the primary tumors could be removed by comparatively limited intestinal resections although bulky mesenteric metastases were often dissected from the mesenteric vessels. Liver metastases, found in 49% of the patients, were generally bilateral and multiple, and major hepatic metastases were resected in 6 patients. The results support a role for surgery also in the more compromised patients with mid-gut carcinoid tumors and that such intervention may be associated with considerable symptomatic relief and substantial periods of survival.

APUD update

Apudomas are a diffuse group of tumors that have interested surgeons for a long time. With recent developments in their radiological localization and pharmacological control, they are now treated in a truly multidisciplinary approach. In this chapter, recent developments in the radiological, surgical, and medical approaches to these tumors are reviewed. Emphasis is placed on how non-surgical developments have affected the surgical treatment of specific apudomas. Resulting changes in surgical philosophy are also reviewed.

Zollinger-Ellison Syndrome in the Intensive Care Setting

Management of patients with Zollinger-Ellison syn drome differs markedly from management of patients with idiopathic gastric acid hypersecretion or routine peptic ulcer disease. Because of the possible complica tions arising from gastric acid hypersecretion or from complications caused by the gastrinoma itself, patients with these disorders frequently present to critical care physicians. It is important that critical care physicians be familiar with the acute presentation of patients with Zollinger-Ellison syndrome as well as the appropriate treatment. We review the important points pertaining to the recognition and treatment of Zollinger-Ellison syn drome in the acute care setting.

Treatment of malignant metastatic midgut carcinoid tumours with recombinant human alpha2b interferon with or without prior hepatic artery embolization

Nineteen patients with histologically verified midgut carcinoid tumours and liver metastases were included in a prospective study with daily recombinant human alpha 2b interferon injections of 5 million IU subcutaneously for 1 year. All had as much as possible of the primary tumour removed at laparotomy. Whenever technically possible (in seven cases), an embolization of the hepatic arteries was performed before interferon start. The response rate of the combined embolization and interferon treatment (n = 7) was 86% after 1 year, as judged from either a 50% reduction in excretion of 5-hydroxy-3-indoleacetic acid in the urine or a 50% reduction in the area of the largest liver metastasis as evaluated by computed tomography. All patients experienced an improvement in diarrhoea and/or flushing. When interferon was given alone (n = 12), 40% responded on the basis of objective criteria (50% after 6 months), whereas an improvement in either diarrhoea or flushing was experienced by 70% (75% after 6 months). In this group one patient had died and one had decided to withdraw after 6 months, at which time both were responders. We conclude that interferon seems to be an effective treatment of malignant metastatic midgut carcinoid tumours and that embolization of the liver arteries seems to increase the response rate, as judged after 1 year.

Recombinant alpha-2 interferon with or without hepatic artery embolization in the treatment of midgut carcinoid tumours. A preliminary report

Nineteen patients with histologically verified midgut carcinoid tumours and liver metastases were included in a prospective study with daily interferon therapy 3 mill IU x m-2 subcutaneously for one year. All had the primary tumour removed at laparotomy, and whenever technically possible, an embolization of the hepatic arteries was performed prior to interferon start. Recombinant human alpha-2b interferon from Schering was employed. When interferon was given alone for one year 40% responded, judged from either a 50% reduction in excretion of 5-hydroxy-indoleacetic acid in the urine or a 50% reduction in the area of the largest liver metastasis, as evaluated by computer tomography. One patient died later on and one withdrew from therapy of her own will; both were responders at the evaluation at 6 months. When prior embolization of the liver arteries had been performed, the response rate was 85% after one year. When diarrhoea and/or flushing was evaluated, 70% had response on interferon alone, while all patients experienced improvement after the combined procedure. We conclude that interferon is an effective treatment of malignant metastatic midgut carcinoid and that embolization of the liver arteries seems to increase the response rate.